Publications by authors named "Wonnop Visessanguan"

74 Publications

In Vitro Mechanism Assessment of Zearalenone Removal by Plant-Derived BCC 47723.

Toxins (Basel) 2021 04 19;13(4). Epub 2021 Apr 19.

National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Thailand Science Park, Phahonyothin Road, Pathum Thani 12120, Thailand.

Zearalenone (ZEA) is a harmful secondary fungal metabolite, produced primarily by plant pathogenic fungi mostly belonging to the genus . It is involved in reproductive disorders in animals since its structure is similar to the estrogen hormone. This induces precocious pubertal changes, fertility problems, and hyper estrogenic disorders. The main objectives of this study were to evaluate the ZEA removal capacity of plant-derived lactic acid bacteria (LAB) and to investigate the possible components and mechanisms involved in the removal of ZEA by physically and chemically treated plant-derived LAB. The bacterial cells were characterized using scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), and the analysis of zeta potential, and hydrophobic index. Results revealed that 17 out of 33 plant-derived LAB exhibited ZEA removal from liquid medium. The percentage of removal ranged from 0.5-23% and BCC 47723, isolated from wild spider flower pickle (Pag-sian-dorng), exhibited the highest removal. The alteration of proteins on BCC 47723 structure by Sodium dodecyl sulphate (SDS) treatment was positively affected on ZEA removal, whereas that of lipids on ZEA removal was negatively observed. Heat treatment influenced the higher ZEA adsorption. SEM images showed that the morphologies of modified bacterial cells were distinctly deformed and damaged when compared with untreated control. FTIR analysis indicated that the original functional groups, which included amide (C=O, C-N), carboxyl (C=O, C-O, O-H), methylene (C=C), and alcohol (O-H) groups, were not changed after ZEA adsorption. The zeta potential indicated that electrostatic interaction was not involved in the ZEA removal, while hydrophobicity was the main force to interact with ZEA. These findings can conclude that adsorption by hydrophobicity is the main mechanism for ZEA removal of plant-derived BCC 47723. The alteration of bacterial cell structure by heat treatment enhanced the efficiency of BCC 47723 for ZEA reduction. Its activity can be protected by the freeze-drying technique. Hence, plant-derived BCC 47723 can be considered as an organic adsorbent for ZEA reduction in food and feedstuff.
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http://dx.doi.org/10.3390/toxins13040286DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8073407PMC
April 2021

Influence of non-phosphate and low-sodium salt marination in combination with tumbling process on properties of chicken breast meat affected by white striping abnormality.

J Food Sci 2021 Feb 12;86(2):319-326. Epub 2021 Jan 12.

National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phahonyothin Rd, Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand.

This study investigated the effects of non-phosphate and low-sodium (NPLS) marination on properties of white striping chicken breasts (WSCB). Chicken breasts were collected from slaughterhouse and classified as normal (NCB, n = 24) and severe WS (WSCB, n = 120). Sixty WSCB samples were vacuum-tumbled (30 min, 2 °C) with NPLS solution, containing 2.8% (w/v) potassium bicarbonate, 2.9% (w/v) potassium chloride, and 1.5% (w/v) sorbitol at the ratio of meat-to-marinade of 4 to 1 (w/w). The other 60 WSCB received no marination were assigned as nonmarinated WSCB. Properties of marinated (n = 12) and nonmarinated (n = 12) WSCB samples were determined at 0, 3, 7, 10, and 14 days of the storage at 4 °C. Properties of the NCB were also determined on day 0. Concerning day 0, the marinated WSCB exhibited higher (p < 0.05) pH, moisture content, total cooked yield, protein solubility, hardness, cohesiveness, and chewiness along with lower (p < 0.05) cooked loss, expressible water, and shear force than those of nonmarinated WSCB and NCB. Based on nuclear magnetic resonance spectroscopy, bound, intra-myofibrillar, and extra-myofibrillar water of cooked marinated WSCB were greater (p < 0.05) than those of cooked nonmarinated WSCB. The greater (p < 0.05) weight loss, moisture content, and total cooking yield were observed in marinated samples compared to those of nonmarinated WSCB throughout the storage period. Although microbial stability was reduced (p < 0.05), no difference (p ≥ 0.05) in lipid oxidation was detected between the treatments. The findings suggest the NPLS marination as a promising process for improving water holding capacity of the WSCB. PRACTICAL APPLICATION: This study presents the promising application of non-phosphate, low-sodium (NPLS) marination combined with vacuum-tumbling in improving water holding capacity of chicken breast meat affected with white striping condition. Although microbial stability of the marinated breast was negatively affected, no adverse impacts on lipid oxidation was observed during storage up to 14 days.
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http://dx.doi.org/10.1111/1750-3841.15565DOI Listing
February 2021

Genome sequences of antibiotic-resistant Streptococcus suis strains isolated from human patients and diseased and asymptomatic pigs in Thailand.

Infect Genet Evol 2021 Jan 13;87:104674. Epub 2020 Dec 13.

Department of Biomedical Informatics, University of Arkansas for Medical Sciences, Little Rock, AR, USA. Electronic address:

Streptococcus suis, a zoonotic bacterial pathogen, has negative economic impacts on both intensive swine production and human health worldwide. Whole-genome sequencing and comparative genomic analysis have been widely used for comprehensive classification and investigation of the genetic basis of several S. suis strains obtained from distinct hosts in different geographic areas, revealing great genetic diversity of this zoonotic pathogen. In this study, whole-genome sequences of antibiotic-resistant S. suis strains isolated from human patients (2 strains), diseased pigs (4 strains), and asymptomatic pigs (3 strains) in Thailand were compared with known genomes of 1186 S. suis strains. Single-nucleotide polymorphism-based phylogenetic analysis indicated that the Thai-isolated S. suis strains have close genetic relatedness to S. suis strains isolated from Canada, China, Denmark, Netherlands, United Kingdom, and United States of America. The genome analysis revealed genes conferring antibiotic resistance (aad(6), ant(6)-Ia, ermB, tet(O), patB, and sat4) and gene clusters (aph(3')-IIIa and aac(6')-Ie-aph(2″)-Ia) associated with aminoglycoside, macrolide, and fluoroquinolone resistance in S. suis in Thailand. This work provides additional resources for future genomic epidemiology investigation of S. suis.
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http://dx.doi.org/10.1016/j.meegid.2020.104674DOI Listing
January 2021

Nutritional Properties and Oxidative Indices of Broiler Breast Meat Affected by Wooden Breast Abnormality.

Animals (Basel) 2020 Dec 2;10(12). Epub 2020 Dec 2.

National Center for Genetic Engineering and Biotechnology (BIOTEC), Pathum Thani 12120, Thailand.

Wooden breast (WB) abnormality adversely impacts the quality of chicken meat and has been linked with oxidative stress. In this study, breast samples were taken from carcasses of 7-week-old Ross 308 broilers 20-min and 24-h postmortem. Five WB and seven non-WB control samples were assigned based on palpatory hardness (non-WB = no unusual characteristics and WB = focal or diffused hardness). WB exhibited lower contents of protein and the amino acids, i.e., isoleucine, leucine and valine, lighter surface color, lower shear force, greater drip loss and altered mineral profiles ( ≤ 0.05). Despite no difference in lipid oxidation, a greater degree of protein oxidation was found in the WB meat ( ≤ 0.05). Absolute transcript abundances of superoxide dismutase, hypoxia inducible factor 1 alpha and pyruvate dehydrogenase kinase 1 were greater in WB ( ≤ 0.05), whereas lactate dehydrogenase A expression was lower in WB ( ≤ 0.05). The findings support an association between oxidative stress and the altered nutritional and technological properties of chicken meat in WB.
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http://dx.doi.org/10.3390/ani10122272DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7759853PMC
December 2020

An efficient ABC transporter signal peptide directs heterologous protein secretion in food-grade hosts.

World J Microbiol Biotechnol 2020 Sep 19;36(10):154. Epub 2020 Sep 19.

Microbial Cell Factory Research Team, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Road, Klong 1, Klong Luang, 12120, Pathumthani, Thailand.

An efficient expression-secretion system for heterologous protein production in food-grade hosts, Lactobacillus plantarum and Bacillus subtilis, is still required to broaden their applications. The optimal signal peptide compatible with both the desired protein and the target host is important for the system. Here, we constructed new expression-secretion vectors to be used in both bacteria. A natural plasmid originating from food-grade L. plantarum BCC9546 was used as a core vector combined with a strong constitutive promoter, L-ldh promoter, and various signal peptides from several types of L. plantarum proteins: ABC transporter, cell wall-associated and extracellular proteins. A gene encoding 88-kDa amylase isolated from starch-related L. plantarum TBRC470 was used as a gene model to evaluate the systems. By comparing the amounts of secreted amylase from the recombinant strains to that of wild type, all signal peptides gave higher yields of secreted amylase in recombinant B. subtilis. Interestingly, two ABC transporter signal peptides from glutamine and mannose ABC transporters provided noticeably high levels of secreted amylase in recombinant L. plantarum. Moreover, these signal peptides also gave high yields of secreted amylase in recombinant B. subtilis. From the results, the signal peptide of glutamine ABC transporter, which functions in essential amino acid transportation that is a precursor for synthesis of nitrogen-containing compounds and nitrogen homeostasis, has a potential use in development of an efficient expression-secretion system for heterologous protein production in both food-grade hosts.
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http://dx.doi.org/10.1007/s11274-020-02932-0DOI Listing
September 2020

Metagenomics in bioflocs and their effects on gut microbiome and immune responses in Pacific white shrimp.

Fish Shellfish Immunol 2020 Nov 26;106:733-741. Epub 2020 Aug 26.

National Center for Genetic Engineering and Biotechnology (BIOTEC), Phahonyothin Rd., Pathumthani, 12120, Thailand.

Biofloc systems generate and accumulate microbial aggregates known as bioflocs. The presence of bioflocs has been shown to change gut bacterial diversity and stimulate innate immunity in shrimp. The microbial niche of bioflocs may therefore have the potential to drive shifts in the shrimp gut microbiota associated with stimulation of innate immunity. We performed shotgun metagenomic analysis and 16S rRNA-based amplicon sequencing to characterize complex bacterial members in bioflocs and the shrimp digestive tract, respectively. Moreover, we determined whether biofloc-grown shrimp with discrete gut microbiomes had an elevation in local immune-related gene expression and systemic immune activities. Our findings demonstrated that the bacterial community in bioflocs changed dynamically during Pacific white shrimp cultivation. Metagenomic analysis revealed that Vibrio comprised 90% of the biofloc population, while Pseualteromonas, Photobacterium, Shewanella, Alteromonas, Bacillus, Lactobacillus, Acinetobacter, Clostridium, Marinifilum, and Pseudomonas were also detected. In the digestive tract, biofloc-grown shrimp maintained the presence of commensal bacteria including Vibrio, Photobacterium, Shewanella, Granulosicoccus, and Ruegeria similar to control shrimp. However, Vibrio and Photobacterium were significantly enriched and declined, respectively, in biofloc-grown shrimp. The presence of bioflocs upregulated immune-related genes encoding serine proteinase and prophenoloxidase in digestive organs which are routinely exposed to gut microbiota. Biofloc-grown shrimp also demonstrated a significant increase in systemic immune status. As a result, the survival rate of biofloc-grown shrimp was substantially higher than that of the control shrimp. Our findings suggested that the high relative abundance of vibrios in bioflocs enriched the number of vibrios in the digestive tract of biofloc-grown shrimp. This shift in gut microbiota composition may be partially responsible for local upregulation of immune-related gene expression in digestive organs and systemic promotion of immune status in circulating hemolymph.
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http://dx.doi.org/10.1016/j.fsi.2020.08.042DOI Listing
November 2020

Investigation on the Double CutOff Phenomenon Observed in Protocatechuic Acid and Its Alkyl Esters under Various CAT-Based Assays.

J Agric Food Chem 2020 Sep 24;68(35):9568-9575. Epub 2020 Aug 24.

Food Biotechnology Research Team,f Functional Ingredients and Food Innovation Research Group, National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phaholyothin Rd., Klong Luang, Pathumthani 12120, Thailand.

A strange cutoff phenomenon of a series of protocatechuic acid alkyl esters had been noticed using the conjugated autoxidizable triene (CAT) assay. Two parabolic shapes of antioxidant activities of protocatechuic acid alkyl esters described as ″the double cutoff effect″ have been speculated as a result of an oxidative driving force generated in the aqueous phase. The aim of this research was to investigate the double cutoff effect using various types of oxidation driving forces in different CAT-based assays. To further explain the phenomenon, the natural oxidation of conjugated autoxidizable triene (NatCAT) assay has been developed for the first time by relying solely on only the lipid autoxidation of tung oil-in-water (O/W) emulsions. In conclusion, NatCAT exhibited different antioxidant and oxidation patterns from both CAT and apolar radical-initiated CAT assays, and only one cutoff point was obtained. This discovery would lead to a greater understanding of the complexity of antioxidant/lipid oxidation dynamics in O/W emulsion systems.
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http://dx.doi.org/10.1021/acs.jafc.0c03825DOI Listing
September 2020

Aflatoxin B-degrading activity from BCC 42005 isolated from fermented cereal products.

Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2020 Sep 28;37(9):1579-1589. Epub 2020 Jul 28.

School of Food Science and Technology, Faculty of Science and Technology, Thammasat University (Rangsit Campus) , Khong Luang, Pathumthani, Thailand.

Aflatoxin B is a naturally occurring mycotoxin that is produced as secondary metabolite by spp., especially and . This is the most severe toxin due to its carcinogenic, mutagenic, and teratogenic properties. Hence, methods for toxin degradation have been received increasing interest from both scientific communities and industries. In this study, 32 isolates of spp. from various fermented cereal products were screened for their aflatoxin B degradation ability. The results indicated the extracellular fraction of BCC 42005 isolated from Iru (African locust bean) potentially possessed aflatoxin B-degrading ability. The maximum activity of the active fraction was at 50°C and pH 8.0. The activity was stable in a wide range of pH (5.0-8.0) and temperature (25-60°C). The aflatoxin B-degrading mechanisms of this strain may be possibly involved by enzyme(s). This extracellular fraction was not toxic at IC 4 mg/ml and it can be combined with water as a soaking agent for maize, which results in 54% of aflatoxin B reduction after contact time 120 min. Hence, the extracellular fraction of BCC 42005 can be further applied as an effective soaking agent in a pretreatment process with a practical and easy-to-implement condition and also probably used to reduce the aflatoxin B contamination in other foods and feeds commodities.
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http://dx.doi.org/10.1080/19440049.2020.1778182DOI Listing
September 2020

Transcriptional Profiles of Skeletal Muscle Associated With Increasing Severity of White Striping in Commercial Broilers.

Front Physiol 2020 16;11:580. Epub 2020 Jun 16.

National Center for Genetic Engineering and Biotechnology (BIOTEC), Thailand Science Park, Pathum Thani, Thailand.

Development of the white striping (WS) abnormality adversely impacts overall quality of broiler breast meat. Its etiology remains unclear. This study aimed at exploring transcriptional profiles of broiler skeletal muscles exhibiting different WS severity to elucidate molecular mechanisms underlying the development and progression of WS. Total RNA was isolated from pectoralis major of male 7-week-old Ross 308 broilers. The samples were classified as mild ( = 6), moderate ( = 6), or severe ( = 4), based on number and thickness of the white striations on the meat surface. The transcriptome was profiled using a chicken gene expression microarray with one-color hybridization technique. Gene expression patterns of each WS severity level were compared against each other; hence, there were three comparisons: moderate vs. mild (C1), severe vs. moderate (C2), and severe vs. mild (C3). Differentially expressed genes (DEGs) were identified using the combined criteria of false discovery rate ≤ 0.05 and absolute fold change ≥1.2. Differential expression of 91, 136, and 294 transcripts were identified in C1, C2, and C3, respectively. There were no DEGs in common among the three comparisons. Based on pathway analysis, the enriched pathways of C1 were related with impaired homeostasis of macronutrients and small biochemical molecules with disrupted Ca-related pathways. Decreased abundance of the period circadian regulator suggested the shifted circadian phase when moderate WS developed. The enriched pathways uniquely obtained in C2 were RNA degradation, Ras signaling, cellular senescence, axon guidance, and salivary secretion. The DEGs identified in those pathways might play crucial roles in regulating cellular ion balances and cell-cycle arrest. In C3, the pathways responsible for phosphatidylinositol 3-kinase-Akt signaling, p53 activation, apoptosis, and hypoxia-induced processes were modified. Additionally, pathways associated with a variety of diseases with the DEGs involved in regulation of [Ca], collagen formation, microtubule-based motor, and immune response were identified. Eight pathways were common to all three comparisons (i.e., calcium signaling, Ras-associated protein 1 signaling, ubiquitin-mediated proteolysis, vascular smooth muscle contraction, oxytocin signaling, and pathway in cancer). The current findings support the role of intracellular ion imbalance, particularly Ca, oxidative stress, and impaired programmed cell death on WS progression.
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http://dx.doi.org/10.3389/fphys.2020.00580DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7308426PMC
June 2020

Safety Assessment of a Nham Starter Culture Lactobacillus plantarum BCC9546 via Whole-genome Analysis.

Sci Rep 2020 06 24;10(1):10241. Epub 2020 Jun 24.

National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand.

The safety of microbial cultures utilized for consumption is vital for public health and should be thoroughly assessed. Although general aspects on the safety assessment of microbial cultures have been suggested, no methodological detail nor procedural guideline have been published. Herein, we propose a detailed protocol on microbial strain safety assessment via whole-genome sequence analysis. A starter culture employed in traditional fermented pork production, nham, namely Lactobacillus plantarum BCC9546, was used as an example. The strain's whole-genome was sequenced through several next-generation sequencing techniques. Incomplete plasmid information from the PacBio sequencing platform and shorter chromosome size from the hybrid Oxford Nanopore-Illumina platform were noted. The methods for 1) unambiguous species identification using 16S rRNA gene and average nucleotide identity, 2) determination of virulence factors and undesirable genes, 3) determination of antimicrobial resistance properties and their possibility of transfer, and 4) determination of antimicrobial drug production capability of the strain were provided in detail. Applicability of the search tools and limitations of databases were discussed. Finally, a procedural guideline for the safety assessment of microbial strains via whole-genome analysis was proposed.
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http://dx.doi.org/10.1038/s41598-020-66857-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7314741PMC
June 2020

Levansucrase from KK9 and Its Y237S Variant Producing the High Bioactive Levan-Type Fructooligosaccharides.

Biomolecules 2020 04 29;10(5). Epub 2020 Apr 29.

Department of Chemistry, Faculty of Liberal Arts and Science, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand.

Levan-typed fructooligosaccharide (LFOS), a β-2,6 linked oligofructose, displays the potential application as a prebiotic and therapeutic dietary supplement. In the present study, LFOS was synthesized using levansucrase from KK9 (LsKK9). The wild-type LsKK9 was cloned and expressed in , and purified by cation exchanger chromatography. Additionally, Y237S variant of LsKK9 was constructed based on sequence alignment and structural analysis to enhance the LFOS production. High-performance anion-exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD) analysis indicated that Y237S variant efficiently produced a higher amount of short-chain LFOS than wild type. Also, the concentration of enzyme and sucrose in the reactions was optimized. Finally, prebiotic activity assay demonstrated that LFOS produced by Y237S variant had higher prebiotic activity than that of the wild-type enzyme, making the variant enzyme attractive for food biotechnology.
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http://dx.doi.org/10.3390/biom10050692DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7277640PMC
April 2020

The Effectiveness of Durian Peel as a Multi-Mycotoxin Adsorbent.

Toxins (Basel) 2020 02 8;12(2). Epub 2020 Feb 8.

Institute of Sciences of Food Production (ISPA), National Research Council (CNR), Via Amendola 122/O, 70126 Bari, Italy.

Durian peel (DP) is an agricultural waste that is widely used in dyes and for organic and inorganic pollutant adsorption. In this study, durian peel was acid-treated to enhance its mycotoxin adsorption efficacy. The acid-treated durian peel (ATDP) was assessed for simultaneous adsorption of aflatoxin B (AFB), ochratoxin A (OTA), zearalenone (ZEA), deoxynivalenol (DON), and fumonisin B (FB). The structure of the ATDP was also characterized by SEM-EDS, FT-IR, a zetasizer, and a surface-area analyzer. The results indicated that ATDP exhibited the highest mycotoxin adsorption towards AFB (98.4%), ZEA (98.4%), and OTA (97.3%), followed by FB (86.1%) and DON (2.0%). The pH significantly affected OTA and FB adsorption, whereas AFB and ZEA adsorption was not affected. Toxin adsorption by ATDP was dose-dependent and increased exponentially as the ATDP dosage increased. The maximum adsorption capacity (Q), determined at pH 3 and pH 7, was 40.7 and 41.6 mmol kg for AFB, 15.4 and 17.3 mmol kg for ZEA, 46.6 and 0.6 mmol kg for OTA, and 28.9 and 0.1 mmol kg for FB, respectively. Interestingly, ATDP reduced the bioaccessibility of these mycotoxins after gastrointestinal digestion using an in vitro validated, static model. The ATDP showed a more porous structure, with a larger surface area and a surface charge modification. These structural changes following acid treatment may explain the higher efficacy of ATDP in adsorbing mycotoxins. Hence, ATDP can be considered as a promising waste material for mycotoxin biosorption.
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http://dx.doi.org/10.3390/toxins12020108DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7076778PMC
February 2020

PSO-LocBact: A Consensus Method for Optimizing Multiple Classifier Results for Predicting the Subcellular Localization of Bacterial Proteins.

Biomed Res Int 2019 19;2019:5617153. Epub 2019 Nov 19.

Biochemical Engineering and Systems Biology Research Group, National Center for Genetic Engineering and Biotechnology (BIOTEC), King Mongkut's University of Technology Thonburi, Bangkhuntien, Bangkok 10150, Thailand.

Several computational approaches for predicting subcellular localization have been developed and proposed. These approaches provide diverse performance because of their different combinations of protein features, training datasets, training strategies, and computational machine learning algorithms. In some cases, these tools may yield inconsistent and conflicting prediction results. It is important to consider such conflicting or contradictory predictions from multiple prediction programs during protein annotation, especially in the case of a multiclass classification problem such as subcellular localization. Hence, to address this issue, this work proposes the use of the particle swarm optimization (PSO) algorithm to combine the prediction outputs from multiple different subcellular localization predictors with the aim of integrating diverse prediction models to enhance the final predictions. Herein, we present PSO-LocBact, a consensus classifier based on PSO that can be used to combine the strengths of several preexisting protein localization predictors specially designed for bacteria. Our experimental results indicate that the proposed method can resolve inconsistency problems in subcellular localization prediction for both Gram-negative and Gram-positive bacterial proteins. The average accuracy achieved on each test dataset is over 98%, higher than that achieved with any individual predictor.
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http://dx.doi.org/10.1155/2019/5617153DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6925685PMC
May 2020

Optimal immobilization of trypsin from the spleen of albacore tuna (Thunnus alalunga) and its characterization.

Int J Biol Macromol 2020 Jan 20;143:462-471. Epub 2019 Nov 20.

Department of Food Science and Technology, Faculty of Agro- and Bio-Industry, Thaksin University, Phatthalung Campus, Phatthalung 93210, Thailand. Electronic address:

Trypsin purified from the spleen of albacore tuna was immobilized onto Octyl Sepharose CL-4B, glutaraldehyde activated silica and 5'-4,4'-dimethyltryptamine-thymidine-succinyl controlled pore glass. Trypsin was highly and efficiently immobilized onto Octyl Sepharose CL-4B, with the highest activity (6.26 U/g support) and specific activity (1.45 U/mg bound protein). The optimum conditions for trypsin immobilization onto Octyl Sepharose CL-4B were 40 mg/mL trypsin solution, pH 7 at 4 °C for 6 h of incubation time. The optimal temperature and pH for the hydrolysis of N-α-benzoyl-DL-arginine-p-nitroanilide (DL-BAPNA) by the immobilized trypsin were 55 °C and 8.5, both of which were higher than that of the free form. In comparison with free enzyme, the immobilized trypsin exhibited greater resistances against thermal inactivation and organic solvents. The immobilized enzyme was less sensitive to inhibition by the soybean trypsin inhibitor compared with the free soluble form of the enzyme. According to the results, the immobilized trypsin and free enzyme retained 83% and 47% of their activity, respectively, when they were incubated with 1 μM of the soybean trypsin inhibitor. For the reusability study, the immobilized trypsin maintained 60% of its activity after 4 periods of activity, indicating that the immobilized trypsin had appropriate stability and could be reused.
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http://dx.doi.org/10.1016/j.ijbiomac.2019.10.030DOI Listing
January 2020

sp. nov., a moderately halophilic bacterium isolated from shrimp paste ().

Int J Syst Evol Microbiol 2019 Nov;69(11):3529-3536

Department of Biochemistry and Microbiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand.

A Gram-stain-positive, aerobic, spore-forming, moderately halophilic bacterium, SSKP1-9, was isolated from traditional salted shrimp paste () produced in Samut Sakhon Province, Thailand. This strain grew optimally at 37-40 °C, pH 7.0 and in the presence of 8-16 % (w/v) NaCl. The 16S rRNA gene sequence similarity values between strain SSKP1-9 and TISTR 1535 and TISTR 1549 were 98.7 and 97.2 %, respectively. Based on 16S rRNA gene sequence similarity, strain SSKP1-9 represents a distinct novel species, as shown by phenotypic traits, DNA-DNA hybridization and average nucleotide identity values. In addition, the whole-cell protein profile confirmed the novelty of the taxon. The genomic DNA GC content was 44.6 mol%. The major isoprenoid quinone was MK-7. The cell-wall peptidoglycan contained -diaminopimelic acid. Polar lipid analysis revealed the presence of phosphatidylglycerol, diphosphatidylglycerol, four unidentified lipids, an unidentified phospholipid and an unidentified glycolipid. The major cellular fatty acids were anteiso-C, anteiso-C and iso-C. The results of phenotypic and chemotaxonomic characteristics and whole-genome analysis support that strain SSKP1-9 represents a novel species of , for which the name sp. nov. is proposed. The type strain is SSKP1-9 (=JCM 32625=TISTR 2597).
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http://dx.doi.org/10.1099/ijsem.0.003658DOI Listing
November 2019

Absolute expressions of hypoxia-inducible factor-1 alpha (HIF1A) transcript and the associated genes in chicken skeletal muscle with white striping and wooden breast myopathies.

PLoS One 2019 8;14(8):e0220904. Epub 2019 Aug 8.

National Center for Genetic Engineering and Biotechnology (BIOTEC), Khlong Nueng, Khlong Luang, Pathum Thani, Thailand.

Development of white striping (WS) and wooden breast (WB) in broiler breast meat have been linked to hypoxia, but their etiologies are not fully understood. This study aimed at investigating absolute expression of hypoxia-inducible factor-1 alpha subunit (HIF1A) and genes involved in stress responses and muscle repair using a droplet digital polymerase chain reaction. Total RNA was isolated from pectoralis major collected from male 6-week-old medium (carcass weight ≤ 2.5 kg) and heavy (carcass weight > 2.5 kg) broilers. Samples were classified as "non-defective" (n = 4), "medium-WS" (n = 6), "heavy-WS" (n = 7) and "heavy-WS+WB" (n = 3) based on abnormality scores. The HIF1A transcript was up-regulated in all of the abnormal groups. Transcript abundances of genes encoding 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 4 (PFKFB4), lactate dehydrogenase-A (LDHA), and phosphorylase kinase beta subunit (PHKB) were increased in heavy-WS but decreased in heavy-WS+WB. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was up-regulated in non-defective samples. The muscle-specific mu-2 isoform of glutathione S-transferases (GSTM2) was up-regulated in the abnormal samples, particularly in the heavy groups. The genes encoding myogenic differentiation (MYOD1) and myosin light chain kinase (MYLK) exhibited similar expression pattern, of which medium-WS and heavy-WS significantly increased compared to non-defective whereas expression in heavy-WS+WB was not different from either non-defective or WS-affected group. The greatest and the lowest levels of calpain-3 (CAPN3) and delta-sarcoglycan (SCGD) were observed in heavy-WS and heavy-WS+WB, respectively. Based on micrographs, the abnormal muscles primarily comprised fibers with cross-sectional areas ranging from 2,000 to 3,000 μm2. Despite induced glycolysis at the transcriptional level, lower stored glycogen in the abnormal muscles corresponded with the reduced lactate and higher pH within their meats. The findings support hypoxia within the abnormal breasts, potentially associated with oversized muscle fibers. Between WS and WB, divergent glucose metabolism, cellular detoxification and myoregeneration at the transcriptional level could be anticipated.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0220904PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6687142PMC
March 2020

Anionic trypsin from the spleen of albacore tuna (Thunnus alalunga): Purification, biochemical properties and its application for proteolytic degradation of fish muscle.

Int J Biol Macromol 2019 Jul 24;133:971-979. Epub 2019 Apr 24.

Department of Food Science and Technology, Faculty of Agro- and Bio-Industry, Thaksin University, Phatthalung Campus, Phatthalung 93210, Thailand. Electronic address:

Anionic trypsin from albacore tuna spleen was purified by chromatographic separations on Q-Sepharose, Superdex 75 and Arginine Sepharose 4B. The trypsin migrated as single bands in both SDS-PAGE and native-PAGE. The molecular weight of purified trypsin was estimated to be 30 kDa using SDS-PAGE. The enzyme exhibited maximal activity at pH 9.0 and 55 °C for hydrolysis of Boc-Val-Pro-Arg-MCA. pH and temperature stabilities of the trypsin were well maintained in the pH range of 6-11 and over a temperature range from 20 up to 50 °C. The enzyme was effectively inhibited by soybean trypsin inhibitor, N‑tosyl‑l‑phenyl‑alanine chloromethyl ketone (TLCK) and Pefabloc SC. The N-terminal amino acid sequence of 20 residues of the purified enzyme was IVGGYECQAHSQPHQVSLNA, which is highly homologous to other fish trypsins. The k/K of the enzyme for Boc-Val-Pro-Arg-MCA was 2.60 ± 0.07 s mM. Purified trypsin also hydrolysed fish muscle proteins, suggesting its effectiveness in degradation of food proteins.
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http://dx.doi.org/10.1016/j.ijbiomac.2019.04.122DOI Listing
July 2019

Antimicrobial susceptibility of Streptococcus suis isolated from diseased pigs, asymptomatic pigs, and human patients in Thailand.

BMC Vet Res 2019 Jan 3;15(1). Epub 2019 Jan 3.

National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Rd., Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand.

Background: Prophylaxis and treatment of emerging zoonotic Streptococcus suis infection in agricultural and healthcare settings mainly rely on antibiotics. However, continued use of antibiotics contributing to emergence and widespread of antibiotic resistant S. suis becomes a significant challenge in many endemic countries, including Thailand. Meanwhile, the knowledge of antibiotic susceptibility patterns of bacterial pathogens is required for overcoming the antimicrobial resistance problem, the information of antibiotic susceptibility of S. suis strains isolated in Thailand remains limited. This study aims to assess the susceptibility of Thai-isolated S. suis strains to different antibiotic classes in order to gain an insight into the distribution of antibiotic-resistant patterns of S. suis strains in different regions of Thailand.

Results: This study revealed the antimicrobial resistance and multidrug resistance of 262 S. suis strains isolated in different regions of Thailand. Susceptibility testing indicated widespread resistance to macrolides and tetracyclines of S. suis strains in the country. Beta-lactam antibiotic drugs (including cefotaxime and ceftiofur), vancomycin, chloramphenicol, as well as florfenicol were potentially the most effective therapeutic drugs for the treatment of S. suis infection in both pigs and humans. High prevalence of intermediate susceptibility of S. suis isolated from asymptomatic pigs for penicillin G, gentamicin, enrofloxacin, and norfloxacin could be the premise of the emergence of S. suis antibiotic resistance. Resistance was also found in S. suis strains isolated from asymptomatic pigs indicating that they could act as reservoirs of antibiotic resistance genes.

Conclusions: To the best of our knowledge, this is the first report on antimicrobial resistance of a large collection of S. suis strains isolated from pigs and humans in Thailand. It revealed the multidrug resistance of S. suis strains in pigs and humans. The information gained from this study raises an awareness and encourage best practices of appropriate antibiotic drug prescribing and use among human health and agriculture sectors.
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http://dx.doi.org/10.1186/s12917-018-1732-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6318959PMC
January 2019

Effects of Bacillus aryabhattai TBRC8450 on vibriosis resistance and immune enhancement in Pacific white shrimp, Litopenaeus vannamei.

Fish Shellfish Immunol 2019 Mar 10;86:4-13. Epub 2018 Nov 10.

Food Biotechnology Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Phahonyothin Rd., Pathumthani, 12120, Thailand.

The use of probiotics in aquaculture is a practical alternative to promote animal health and disease prevention. Meanwhile, this practice can also reduce the use of prophylactic antibiotics. The purpose of this study was to identify candidate probiotics that could control pathogen populations in host's gastrointestinal (GI) tract and stimulate host immunity in shrimp aquaculture. Bacillus aryabhattai TBRC8450, a bacterial strain isolated from the environment in a shrimp farm, has an antimicrobial activity against many pathogenic strains of Vibrio harveyi and V. parahaemolyticus. Supplementation of B. aryabhattai to Pacific white shrimp (Litopenaeus vannamei) not only decreased the abundance of Vibrio populations, but also shifted the bacterial community in the shrimp GI tract. We found that supplementation of B. aryabhattai triggered shrimp innate immunity and antioxidant activities. mRNA expression of genes encoding microbial peptides and antioxidant enzymes, including C-type lectin, penaeidin-3, heat shock protein 60, thioredoxin, and ferritin, was significantly upregulated in the hepatopancreas of shrimp fed B. aryabhattai. Furthermore, phenoloxidase activity in the hemocytes and the total antioxidant activity in the plasma were increased, indicating enhanced immune and antioxidant responses at the systemic level. In contrast, supplementation of B. aryabhattai had no effect on the total hemocyte count and superoxide dismutase activity in the plasma and hepatopancreas. Importantly, a pathogen challenge test using V. harveyi 1562 showed a significant increase in survival rates of shrimp fed B. aryabhattai compared to the control group. Our findings suggest that B. aryabhattai TBRC8450 can likely be used as a probiotic to reduce the population of V. harveyi in the shrimp GI tract and to enhance shrimp innate immunity and antioxidant capacity for vibriosis resistance in shrimp aquaculture.
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http://dx.doi.org/10.1016/j.fsi.2018.11.010DOI Listing
March 2019

Monitoring of white striping and wooden breast cases and impacts on quality of breast meat collected from commercial broilers (Gallus gallus).

Asian-Australas J Anim Sci 2018 Nov 27;31(11):1807-1817. Epub 2018 Aug 27.

Food Biotechnology Research Unit, National Center for Genetic Engineering and Biotechnology, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand.

Objective: This study aimed at investigating white striping (WS) and wooden breast (WB) cases in breast meat collected from commercial broilers.

Methods: A total of 183 breast samples were collected from male Ross 308 broilers slaughtered at the age of 6 weeks (n = 100) and 7 weeks (n = 83). The breasts were subjected to meat defect inspection, meat quality determination and histology evaluation.

Results: Of 183, 4 breasts from 6-week-old broilers were classified as non-defective while the others exhibited the WS lesion. Among the 6-week-old birds, the defective samples from the medium size birds (carcass weight ≤2.5 kg) showed mild to moderate WS degree with no altered meat quality. Some of the breasts from the 6-week-old birds with carcass weight above 2.5 kg exhibited WB in accompanied with the WS condition. Besides of a reduction of protein content, increases in collagen matter and pH values in the defective samples (p<0.05), no other impaired quality indices were detected within this group. All 7-week-old broilers yielded carcasses weighing above 2.5 kg and showed abnormal characteristics with progressive severity. The breasts affected with severe WS and WB showed the greatest cook loss, hardness, springiness and chewiness (p<0.05). Development of WB induced significantly increased drip loss in the samples (p<0.05). Histology indicated necrotic events in the defective myofibers. Based on logistic regression, increasing percent breast weight by one unit enhanced the chance of WS and WB development with advanced severity by 50.9% and 61.0%, respectively. Delayed slaughter age from 6 to 7 weeks increased the likelihood of obtaining increased WS severity by 56.3%.

Conclusion: Cases of WS and WB defects in Southeast Asia have been revealed. Despite few cases of the severe WS and WB, such abnormal conditions significantly impaired technological properties and nutritional quality of broiler breasts.
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http://dx.doi.org/10.5713/ajas.18.0355DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6212750PMC
November 2018

Characterization and Antibacterial Activity Against Helicobacter pylori of Lactic Acid Bacteria Isolated from Thai Fermented Rice Noodle.

Probiotics Antimicrob Proteins 2019 03;11(1):92-102

Department of Biochemistry and Microbiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, 10330, Thailand.

A total of 32 lactic acid bacteria (LAB) were isolated from Khanom-jeen, a Thai traditional fermented rice noodle. They belonged to the genus Leuconostoc (Ln), Lactobacillus (Lb), Enterococcus (E), Lactococcus (Lc), and Weissella (W), based on their phenotypic characteristics and 16S rRNA gene sequence analyses. The strains were identified as Ln. pseudomesenteroides (group 1, two strains), Ln. citreum (group 2, three strains), Ln. lactis (group 3, three strains), Lb. paracasei subsp. tolerans (group 4, two strains), E. faecium (group 5, three strains), Lc. lactis subsp. lactis (group 6, one strain), W. confusa (group 7, six strains), Lb. fermentum (group 8, seven strains), and Lb. plantarum subsp. plantarum and Lb. pentosus (group 9, five strains). Fifteen strains exhibited the inhibitory activity against Helicobacter pylori clinical isolates by spot-on-lawn method. Lb. fermentum P43-01 resisted to bile acids showed the broad spectrum of antimicrobial activity against H. pylori strains MS83 and BK364. These antagonistic effects were associated with proteinaceous compounds which are sensitive to α-chymotrypsin and pepsin. Results indicated that production of bacteriocin-like substances of selected strain might be the significant mechanism that exerted the inhibition on H. pylori. A potential strain could be used as probiotics in alternative or adjunctive therapy for a patient suffering from H. pylori infection.
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http://dx.doi.org/10.1007/s12602-018-9385-zDOI Listing
March 2019

Comparison of Antioxidant Evaluation Assays for Investigating Antioxidative Activity of Gallic Acid and Its Alkyl Esters in Different Food Matrices.

J Agric Food Chem 2017 Aug 15;65(34):7509-7518. Epub 2017 Aug 15.

Food Biotechnology Research Unit, National Center for Genetic Engineering and Biotechnology (BIOTEC) , 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong, Pathumthani 12120, Thailand.

The addition of antioxidants is one of the strategies to inhibit lipid oxidation, a major cause of lipid deterioration in foods leading to rancidity development and nutritional losses. However, several studies have been reported that conventional antioxidant assays, e.g., TPC, ABTS, FRAP, and ORAC could not predict antioxidant performance in several foods. This study aimed to investigate the performance of two recently developed assays, e.g., the conjugated autoxidizable triene (CAT) and the apolar radical-initiated conjugated autoxidizable triene (ApoCAT) assays to predict the antioxidant effectiveness of gallic acid and its esters in selected food models in comparison with the conventional antioxidant assays. The results indicated that the polarities of the antioxidants have a strong impact on antioxidant activities. In addition, different oxidant locations demonstrated by the CAT and ApoCAT assays influenced the overall antioxidant performances of the antioxidants with different polarities. To validate the predictability of the assays, the antioxidative performance of gallic acid and its alkyl esters was investigated in oil-in-water (O/W) emulsions, bulk soybean oils, and roasted peanuts as the lipid food models. The results showed that only the ApoCAT assay could be able to predict the antioxidative performances in O/W emulsions regardless of the antioxidant polarities. This study demonstrated that the relevance of antioxidant assays to food models was strongly dependent on physical similarities between the tested assays and the food structure matrices.
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http://dx.doi.org/10.1021/acs.jafc.7b02503DOI Listing
August 2017

Lactobacillus ixorae sp. nov., isolated from a flower (West-Indian jasmine).

Int J Syst Evol Microbiol 2016 Dec 11;66(12):5500-5505. Epub 2016 Oct 11.

Department of Biochemistry and Microbiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand.

A Gram-stain-positive, lactic acid bacterium, strain Ru20-1T, was isolated from a flower (West-Indian jasmine) collected from Kalasin province, Thailand. A polyphasic approach was used to determine the taxonomic position of this strain. Studies of morphological and biochemical characteristics revealed that strain Ru20-1T belonged to the genus Lactobacillus. The strain was heterofermentative, non-spore-forming and rod-shaped. It produced dl-lactic acid. Based on 16S rRNA gene sequence similarity, this strain was closely related to Lactobacillus lindneri LMG 14528T (96.8 %), Lactobacillus sanfranciscensis NRIC 1548T (95.4 %) and Lactobacillus florum NRIC 0771T (95.2 %), respectively. In addition, the pheS gene sequence of strain Ru20-1T was closely related to those of L. sanfranciscensis NRIC 1548T (92.0 %), L. lindneri LMG 14528T (89.0 %) and L. florum NRIC 0771T(85.0 %). Phylogenetic analysis indicated that strain Ru20-1T was clearly separated from closely related species of the genus Lactobacillus. The DNA G+C content of strain Ru20-1T was 47.8 mol %. The cell-wall peptidoglycan type was l-Lys-d-Asp. The major cellular fatty acids were C18 : 1ω9c, C20 : 0, C20 : 1ω9c and summed feature 7 (unknown 18.846 and/or C19 : 1ω6c and/or C19 : 0 cyclo). On the basis of the data provided, strain Ru20-1T represents a novel species of the genus Lactobacillus, for which the name Lactobacillus ixorae sp. nov. is proposed. The type strain is Ru20-1T (=LMG 29008T=NBRC 111239T=PCU 346T=TISTR 2381T).
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http://dx.doi.org/10.1099/ijsem.0.001547DOI Listing
December 2016

62nd International Congress of Meat Science and Technology.

Meat Sci 2016 Oct;120

National Center for Genetic Engineering and Biotechnology (BIOTEC), Pathum Thani 12120, Thailand. Electronic address:

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http://dx.doi.org/10.1016/j.meatsci.2016.06.025DOI Listing
October 2016

Bacteriocins from lactic acid bacteria and their applications in meat and meat products.

Meat Sci 2016 Oct 13;120:118-132. Epub 2016 Apr 13.

National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Pathum Thani 12120, Thailand. Electronic address:

Meat and meat products have always been an important part of human diet, and contain valuable nutrients for growth and health. Nevertheless, they are perishable and susceptible to microbial contamination, leading to an increased health risk for consumers as well as to the economic loss in meat industry. The utilization of bacteriocins produced by lactic acid bacteria (LAB) as a natural preservative has received a considerable attention. Inoculation of bacteriocin-producing LAB cell as starter or protective cultures is suitable for fermented meats, whilst the direct addition of bacteriocin as food additive is more preferable when live cells of LAB could not produce bacteriocin in the real meat system. The incorporation of bacteriocins in packaging is another way to improve meat safety to avoid direct addition of bacteriocin to meat. Utilization of bacteriocins can effectively contribute to food safety, especially when integrated into hurdle concepts. In this review, LAB bacteriocins and their applications in meat and meat products are revisited. The molecular structure and characteristics of bacteriocins recently discovered, as well as exemplary properties are also discussed.
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http://dx.doi.org/10.1016/j.meatsci.2016.04.004DOI Listing
October 2016

A novel salt-inducible vector for efficient expression and secretion of heterologous proteins in Bacillus subtilis.

J Biotechnol 2016 Mar 12;222:86-93. Epub 2016 Feb 12.

Microbial Cell Factory Laboratory, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113, Thailand Science Park, Phahonyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand. Electronic address:

Bacillus subtilis is commonly used as a host for heterologous protein production via plasmid-based expression system. In order to improve product safety, avoid carbon catabolite repression and lower production cost, a novel salt-inducible vector, pSaltExSePR5, was developed based on a natural plasmid of Lactobacillus plantarum BCC9546. Salt-inducible promoter opuAA and a DNA fragment encoding a signal peptide of subtilisin E (SubE) were sequentially added to the core shuttle vector to facilitate expression and secretion of a target protein in B. subtilis. To evaluate the effectiveness of this system under salt induction, a protease gene from Halobacillus sp. without its native signal sequence was inserted in the pSaltExSePR5 plasmid downstream of SubE signal sequence and transformed into B. subtilis WB800. Protease activities from cell-free supernatants of the recombinant bacteria cultures induced with 0.5-6% NaCl were analyzed. The highest protease activity of 9.1 U/ml was obtained after induction with 4% NaCl, while the non-induced culture exhibited activity of 0.128 U/ml. The results demonstrated that pSaltExSePR5 provides an alternative vector for efficient and simple production of heterologous proteins in B. subtilis with a safer and more economic inducer.
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http://dx.doi.org/10.1016/j.jbiotec.2016.02.019DOI Listing
March 2016

Enhanced production of histamine dehydrogenase by Natrinema gari BCC 24369 in a non-sterile condition.

J Gen Appl Microbiol 2015 ;61(6):232-40

Department of Food Technology, Faculty of Agro-Industry, Prince of Songkla University.

The production of histamine dehydrogenase (HADH) by Natrinema gari BCC 24369, a halophilic archeaon isolated from fish sauce, was optimized and scaled up under a non-sterile condition. Through statistical design by Plackett-Burman design (PBD), casamino acid, NaCl, MgSO4·7H2O and FeCl2·4H2O were identified as the significant medium compositions influencing HADH production. Central composite design (CCD) was employed to identify the optimal values of individual composition yielding the maximum HADH production. The analysis indicated that the optimal medium was composed of 15 g/l casamino acid, 75 g/l MgSO4·7H2O, 273 g/l NaCl, 2.5 mg/l FeCl2·4H2O, 10 g/l yeast extract, 5 g/l sodium glutamate and 5 g/l KCl. Based on the one-factor-at-a-time (OFAT) method, the optimum initial pH of the culture medium and the incubation temperature for HADH production were 7.5 and 37 °C, respectively. The production of HADH under optimal conditions was 2.2-fold higher than that under un-optimized conditions. Owing to the halophilic nature of Nnm. gari BCC 24369, a more economical and eco-friendlier HADH production was developed under a completely non-sterile condition. In a 16-l batch cultivation of Nnm. gari BCC 24369, HADH productivity under a non-sterile condition (858 ± 12 U/g cell biomass) was comparable to that under a sterile condition (878 ± 15 U/g cell biomass). These results demonstrate the feasibility and simplicity of HADH production using Nnm. gari BCC 24369 under a non-sterile condition without compromising enzyme yield and any changes in Km value.
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http://dx.doi.org/10.2323/jgam.61.232DOI Listing
November 2016

Monitoring of Chicken RNA Integrity as a Function of Prolonged Postmortem Duration.

Asian-Australas J Anim Sci 2015 Nov;28(11):1649-56

Department of Food Technology, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand.

Gene expression profiling has offered new insights into postmortem molecular changes associated with meat quality. To acquire reliable transcript quantification, high quality RNA is required. The objective of this study was to analyze integrity of RNA isolated from chicken skeletal muscle (pectoralis major) and its capability of serving as the template in quantitative real-time polymerase chain reaction (qPCR) as a function of postmortem intervals representing the end-points of evisceration, carcass chilling and aging stages in chicken abattoirs. Chicken breast muscle was dissected from the carcasses (n = 6) immediately after evisceration, and one-third of each sample was instantly snap-frozen and labeled as 20 min postmortem. The remaining muscle was stored on ice until the next rounds of sample collection (1.5 h and 6 h postmortem). The delayed postmortem duration did not significantly affect A260/A280 and A260/A230 (p≥0.05), suggesting no altered purity of total RNA. Apart from a slight decrease in the 28s:18s ribosomal RNA ratio in 1.5 h samples (p<0.05), the value was not statistically different between 20 min and 6 h samples (p≥0.05), indicating intact total RNA up to 6 h. Abundance of reference genes encoding beta-actin (ACTB), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), hypoxanthine-guanine phosphoribosyltransferase (HPRT), peptidylprolylisomerase A (PPIA) and TATA box-binding protein (TBP) as well as meat-quality associated genes (insulin-like growth factor 1 (IGF1), pyruvate dehydrogenase kinase isozyme 4 (PDK4), and peroxisome proliferator-activated receptor delta (PPARD) were investigated using qPCR. Transcript abundances of ACTB, GAPDH, HPRT, and PPIA were significantly different among all postmortem time points (p<0.05). Transcript levels of PDK4 and PPARD were significantly reduced in the 6 h samples (p<0.05). The findings suggest an adverse effect of a prolonged postmortem duration on reliability of transcript quantification in chicken skeletal muscle. For the best RNA quality, chicken skeletal muscle should be immediately collected after evisceration or within 20 min postmortem, and rapidly preserved by deep freezing.
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http://dx.doi.org/10.5713/ajas.15.0167DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4647106PMC
November 2015

Apolar Radical Initiated Conjugated Autoxidizable Triene (ApoCAT) Assay: Effects of Oxidant Locations on Antioxidant Capacities and Interactions.

J Agric Food Chem 2015 Sep 25;63(34):7546-55. Epub 2015 Aug 25.

Department of Food Science, University of Massachusetts , Chenoweth Laboratory, 100 Holdsworth Way, Amherst, Massachusetts 01003, United States.

Development of an antioxidant assay explaining antioxidant behaviors in complex food systems has been a challenging topic for food scientists. This research aimed to investigate antioxidant capacities and interactions of selected synthetic antioxidants and commercial natural antioxidant extracts using the CAT assay and a newly developed ApoCAT assay, which used water- and lipid-soluble azo radical initiators, respectively. Results suggested that the higher the hydrophobicity of an antioxidant, the higher the antioxidant capacity of an antioxidant observed in the ApoCAT assay. The relationship between the two different assays was explained by the ratio between the ApoCAT and the CAT values. Interestingly, all lipophilic derivatives of the antioxidants exhibited higher ApoCAT/CAT ratios than their hydrophilic derivatives. In the case of the commercial food-grade antioxidants, green tea extract and mixed tocopherols showed a higher antioxidant capacity in the ApoCAT assay than in the CAT assay, while grape seed and rosemary extracts did not show significantly different changes in behaviors in both assays. The study on antioxidant interactions revealed that additive, synergistic, and antagonistic effects between hydrophilic antioxidants and natural extracts, and mixed tocopherols could be observed in both the CAT and the ApoCAT assays, depending on the combined ratios. In most cases, at a particular ratio, the synergistic effect reached the maximum level before suddenly dropping to additive and antagonistic effects in both assays.
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http://dx.doi.org/10.1021/acs.jafc.5b02493DOI Listing
September 2015

Potential of bacteriocin-producing lactic acid bacteria for safety improvements of traditional Thai fermented meat and human health.

Meat Sci 2015 Nov 16;109:101-5. Epub 2015 Jun 16.

National Center for Genetic Engineering and Biotechnology (BIOTEC) 113 Thailand Science Park, Phahonyothin Rd., Klong 1, Klong Luang, Pathumthani 12120, Thailand.

Lactic acid bacteria (LAB) are very important in converting of agricultural products into safe, delicious and shelf stable foods for human consumption. The preservative activity of LAB in foods is mainly attributed to the production of anti-microbial metabolites such as organic acids and bacteriocins which enables them to grow and control the growth of pathogens and spoilage microorganisms. Besides ensuring safety, bacteriocin-producing LAB with their probiotic potentials could also be emerging as a means to develop functional meat products with desirable health benefits. Nevertheless, to be qualified as a candidate probiotic culture, other prerequisite probiotic properties of bacteriocin-producing LAB have to be assessed according to regulatory guidelines for probiotics. Nham is an indigenous fermented sausage of Thailand that has gained popularity and acceptance among Thais. Since Nham is made from raw meat and is usually consumed without cooking, risks due to undesirable microorganisms such as Salmonella spp., Staphylococcus aureus, and Listeria monocytogenes, are frequently observed. With an ultimate goal to produce safer and healthier product, our research attempts on the development of a variety of new Nham products are discussed.
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http://dx.doi.org/10.1016/j.meatsci.2015.05.030DOI Listing
November 2015