Publications by authors named "Longzhan Gan"

25 Publications

  • Page 1 of 1

Exoproduction and biochemical characterization of a novel serine protease from L9 with hide-dehairing activity.

J Microbiol Biotechnol 2021 Nov 20;32(1). Epub 2021 Nov 20.

Key Laboratory of Leather Chemistry and Engineering, Ministry of Education and College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, P.R China.

This study is the first report on production and characterization of the enzyme from an species. A 4.2-fold increase in the extracellular protease (called L9T) production from L9 was achieved through one factor at-a-time approach and response surface methodological optimization. L9 protease exhibited a unique protein band with a mass of 25.9 kDa upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This novel protease was active over a range of pH (4-13), temperatures (30-80 oC) and salt concentrations (0-220 g/L), with the maximal activity observed at pH 7, 70 oC and 20 g/L NaCl. Proteolytic activity was upgraded in the presence of Ag+, Ca2+ and Sr2+, but was totally suppressed by 5 mM phenylmethylsulfonyl fluoride which suggests that this enzyme belongs to the serine protease family. L9 protease was resistant to certain common organic solvents and surfactants; particularly, 5 mM Tween 20 and Tween 80 improved the activity by 63 and 15%, respectively. More importantly, L9 protease was found to be effective in dehairing of goatskins, cowhides and rabbit-skins without damaging the collagen fibers. These properties confirm the feasibility of L9 protease in industrial applications, especially in leather processing.
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http://dx.doi.org/10.4014/jmb.2108.08037DOI Listing
November 2021

Characterization of Structural and Physicochemical Properties of an Exopolysaccharide Produced by sp. F2 From Fermented Soya Beans.

Front Microbiol 2021 29;12:744007. Epub 2021 Oct 29.

College of Biomass Science and Engineering, Sichuan University, Chengdu, China.

The present study sought to isolate a novel exopolysaccharide (EPS-F2) from sp. F2 through ethanol precipitation, anion-exchange, and gel-filtration chromatography and characterize the physicochemical properties by spectral techniques. EPS-F2 was identified as a neutral homo-exopolysaccharide composed of only glucose with a high molecular weight of 1.108 × 10 g/mol. It contained →6)-α-D-Glc-(1→ linkage in the main chain and →3, 6)-α-D-Glc-(1→ branch chain). Moreover, EPS-F2 possessed excellent thermal stability (266.6°C), water holding capacity (882.5%), oil holding capacity (1867.76%), and emulsifying activity against various edible oils. The steady shear experiments exhibited stable pseudo plasticity under various conditions (concentrations, temperatures, and pHs). The dynamic oscillatory measurements revealed that EPS-F2 showed a liquid-like behavior at a low concentration (2.5%), while a solid-like behavior at high concentrations (3.0 and 3.5%). Overall, these results suggest that EPS-F2 could be a potential alternative source of functional additives and ingredients and be applied in food industries.
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http://dx.doi.org/10.3389/fmicb.2021.744007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8586432PMC
October 2021

Mechanism of Cr(VI) reduction by Lysinibacillus sp. HST-98, a newly isolated Cr (VI)-reducing strain.

Environ Sci Pollut Res Int 2021 Jul 30. Epub 2021 Jul 30.

College of Biomass Science and Engineering, Sichuan University, Chengdu, 610065, China.

Facing the increasingly severe Cr(VI) pollution, bioreduction has proved to be an eco-friendly remediation method. An isolated strain identified as Lysinibacillus can relatively reduce Cr(VI) well. Even if the concentration of Cr(VI) increased to 250mg/L, the strain HST-98 could also grow and remove Cr(VI) well. After optimization of reaction conditions, the optimal pH, temperature, and electron donor are 8~9, 36°C, and sodium lactate, respectively. Coexisting metal ions such as Cu, Co, and Mn are beneficial to reduce Cr(VI), while Zn, Ni, and Cd are just the opposite. What is more, the mechanism of the reduction by the strain HST-98 is chiefly mediated by intracellular enzymes. After gene sequence homology blast and analysis, the genes and enzymes related to chromium metabolism in strain HST-98 have been annotated, which helps us to further understand the reduction mechanism of the strain HST-98. In general, Lysinibacillus sp. HST-98 is a potential candidate to repair the Cr(VI)-contaminated sites.
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http://dx.doi.org/10.1007/s11356-021-15424-xDOI Listing
July 2021

sp. nov., isolated from chromium-containing chemical plant soil.

Int J Syst Evol Microbiol 2021 Jul;71(7)

College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, PR China.

A Gram-stain-positive, rod-shaped, aerobic, non-motile, non-sporulating bacterial strain, designated CSA1, was isolated from chromium-containing soil sampled at a chemical plant. Growth of strain CSA1 occurred at pH 6-10 (optimum, pH 7), 15-45 °C (optimum, 30 °C) and in the presence of 0.5-6.5 % (w/v) NaCl (optimum, 2 %). The 16S rRNA gene sequence of strain CSA1 revealed the highest similarity to A2 (97.5 %), K 70/01 (97.3 %), Re6 (96.6 %), F3-P9 (96.2 %), CC-MF41 (96.1 %) and S27 (96.0 %). The draft genome of CSA1 was approximately 3 350 931 bp in size with a G+C content of 70.6 mol%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values among strain CSA1 and the selected species were 74.0-79.2 % (ANIb), 84.3-87.1 % (ANIm) and 21.5-25.4 % (dDDH), which are below the recommended cutoff values for species delineation. The major fatty acids were anteiso-C, iso-C and anteiso-C. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol and an unknown glycolipid. The predominant menaquinones were MK-11, MK-8 and MK-6. The cell-wall amino acids were 2,4-diaminobutyric acid, alanine, glycine, glutamic acid and threonine. From the phenotypic, chemotaxonomic and molecular features, strain CSA1 was considered to represent a novel species of the genus , for which the name sp. nov. is proposed. The type strain is CSA1 (=JCM 34359=CGMCC 1.18746).
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http://dx.doi.org/10.1099/ijsem.0.004923DOI Listing
July 2021

Structural elucidation and physicochemical characteristics of a novel high-molecular-weight fructan from halotolerant Bacillus sp. SCU-E108.

Food Chem 2021 Dec 30;365:130496. Epub 2021 Jun 30.

College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, PR China; Key Laboratory of Leather Chemistry and Engineering (Sichuan University), Ministry of Education, Chengdu 610065, PR China. Electronic address:

An exopolysaccharide, EPS-B108, was isolated from the fermented broth (with a yield of 11.3 g/L) of halotolerant Bacillus sp. SCU-E108 by ethanol precipitation, anion-exchange and gel-filtration chromatography, and well characterized by means of physical, chemical and spectral techniques. Data indicated that EPS-B108 was composed solely of fructose with a high molecular weight of 3.578 × 10 g/mol, and contained a β-(2 → 6)-linked d-Fruf backbone with a single β-d-Fruf at C-1 position. An irregular saccular- or cake-like shape was observed under the enlarged view. It showed no acute oral toxicity in mice, and had good thermal stability (242 °C), solubility in water (91.3%) and oil-holding capacity (1717.0%). Steady-shear flow and dynamical viscoelasticity of aqueous EPS-B108 solutions varied with the polymer concentration, shear rate and temperature, and were described by the Power-law model. Together, these findings support the further application of EPS-B108 as an alternative source of functional food additives and ingredients.
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http://dx.doi.org/10.1016/j.foodchem.2021.130496DOI Listing
December 2021

Optimization of fermentation conditions, purification and rheological properties of poly (γ-glutamic acid) produced by 1006-3.

Prep Biochem Biotechnol 2021 Jul 8:1-9. Epub 2021 Jul 8.

College of Biomass Science and Engineering, Sichuan University, Chengdu, P. R. China.

This study aimed to investigate the optimal fermentation condition, purification and rheological properties of extracellular polymers produced by 1006-3. An optimum temperature of 30.2 °C, inoculation amount of 6.1%, and pH of 8.2 were determined via Response Surface Methodology. The result of amino acid analysis and gel electrophoresis indicated that the obtained polymer contained only glutamic acid, with a wide molecular weight range. This polymer was finally determined as γ-PGA by infrared spectroscopy. The γ-PGA solution displayed a behavior of pseudoplastic non-Newtonian fluid with shear thinning properties, which can be described by the Ostward-de Waele power law model. The apparent viscosity of γ-PGA solution increased with the increase in its concentration from 1% to 10%. The deviation in pH from neutral value, and the addition of NaCl or MgCl can reduce the apparent viscosity of γ-PGA solution, and it was more sensitive to Mg than to Na addition. At the concentration of 4, 6, and 8%, γ-PGA solution showed predominantly viscous response in the range of 0.1-100 rad/s angular frequency (″>). These results indicated the potential application of the γ-PGA as a thickening agent.
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http://dx.doi.org/10.1080/10826068.2021.1941103DOI Listing
July 2021

sp. nov., a moderately halophilic bacterium isolated from wetsalted hides.

Int J Syst Evol Microbiol 2020 Oct 4;70(10):5417-5424. Epub 2020 Sep 4.

Key Laboratory of Leather Chemistry and Engineering (Sichuan University), Ministry of Education, Chengdu 610065, PR China.

A Gram-stain-negative, moderately halophilic strain, designated strain L5, was isolated from wetsalted hides collected from Chengdu, south-west PR China. The cells were motile, facultative aerobic, short rod-shaped and non-endospore-forming. Growth of strain L5 occurred at pH 6-10 (optimum, pH 8), 10-45 °C (optimum, 30 °C) and in the presence of 1-17 % (w/v) NaCl (optimum, 10 %). Results of phylogenetic analyses based on 16S rRNA, and gene sequences and its genome revealed that strain L5 belonged to the genus . Strain L5 was found to be most closely related to the type strains of , , , and (98.8, 98.6, 98.3, 97.9 and 97.4 % 16S rRNA gene sequence similarity, respectively). The draft genome was approximately 4.2 Mb in size with a G+C content of 63.5 mol%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization values among strain L5 and the selected species were 83.3-88.9 % (ANIm), 71.1-87.3 % (ANIb) and 20.2-34.6 %, which are below the recommended cutoff values. Major fatty acids were C, C 7, C 7 and C cyclo 8 and the predominant ubiquinone was Q-9, with minor ubiquinone Q-8 also present. The phospholipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, four unidentified aminophospholipids and three unidentified phospholipids. Based on the mentioned polyphasic taxonomic evidence, strain L5 represents a novel species within the genus , for which sp. nov. is proposed. The type strain is L5 (=CGMCC 1.17335=KCTC 72573).
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http://dx.doi.org/10.1099/ijsem.0.004426DOI Listing
October 2020

Genomic insights into the salt tolerance and cold adaptation of Planococcus halotolerans SCU63.

Arch Microbiol 2020 Dec 17;202(10):2841-2847. Epub 2020 Jul 17.

College of Biomass Science and Engineering, Sichuan University, Chengdu, 610065, People's Republic of China.

Planococcus halotolerans, recently described as a novel species with SCU63 as the type strain, is capable of thriving in up to 15% NaCl and temperatures as low as 0 °C. To better understand its adaptation strategies at the genomic level, strain SCU63 was subjected to whole-genome sequencing and data mining. The high-quality assembly yielded 17 scaffolds with a genome size of 3,622,698 bp. Its genome harbors 3683 protein-coding sequences and 127 RNA genes, as well as three biosynthetic gene clusters and 25 genomic islands. The phylogenomic tree provided compelling insights into the evolutionary relationships of Planococcus. Comparative genomic analysis revealed key similarities and differences in the functional gene categories among Planococcus species. Strain SCU63 was shown to have diverse stress response systems for high salt and cold habitats. Further comparison with three related species showed the presence of numerous unique gene clusters in the SCU63 genome. The strain might serve as a good model for using extremozymes in various biotechnological processes.
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http://dx.doi.org/10.1007/s00203-020-01979-9DOI Listing
December 2020

sp. nov., a moderate halophile isolated from saline soil in Northwest China.

Int J Syst Evol Microbiol 2020 Jun 15;70(6):3701-3710. Epub 2020 May 15.

Key Laboratory of Leather Chemistry and Engineering (Sichuan University), Ministry of Education, Chengdu 610065, PR China.

A moderately halophilic strain, designated SCU50, was recovered from a saline soil sample and characterized by a polyphasic approach. The 16S rRNA gene sequence analysis showed that strain SCU50 belonged to the genus and was most closely related to TP2-8 (98.1 % similarity) and XH-63 (97.7 %). Genomic average nucleotide identity and digital DNA-DNA hybridization analyses confirmed the separate species status of the new isolate relative to other recognized species. The genome size was about 5.09 Mbp and the DNA G+C content was 36.7 mol%. The strain grew optimally at 10-15 % (w/v) NaCl, pH 6.5-7.5 and 25-30 °C. It contained anteiso-C, iso-C and anteiso-C as the dominant fatty acids and menaquinone-7 as the major respiratory quinone. The polar lipid profile was examined and found to comprise diphosphatidylglycerol, phosphatidylglycerol, one unidentified phospholipid and one unidentified lipid. The cell-wall peptidoglycan type was A1γ based on -diaminopimelic acid. Combining the data from phenotypic, chemotaxonomic, genomic and phylogenetic characterization, it was concluded that strain SCU50 should be assigned as representing a novel species within the genus . Thus, a novel taxon named sp. nov. was first established, with SCU50 (=CGMCC 1.17336=KCTC 43107) as the type strain.
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http://dx.doi.org/10.1099/ijsem.0.004224DOI Listing
June 2020

Description of Salinicola corii sp. nov., a Halotolerant Bacterium Isolated from Wetsalted Hides.

Curr Microbiol 2020 Aug 20;77(8):1932-1938. Epub 2020 Apr 20.

Key Laboratory of Leather Chemistry and Engineering (Sichuan University), Ministry of Education, College of Biomass Science and Engineering, Sichuan University, Chengdu, 610065, People's Republic of China.

A novel Gram-stain-negative, moderately halotolerant, rod-shaped bacterium, designated strain L3, was isolated from a wetsalted hide in Chengdu, China. The organism grew optimally at 30 °C, at pH 8 and with 5-10% (w/v) NaCl. The major cellular fatty acids were C, Cω7c, Cω7c and C cyclo ω8c; the predominant respiratory quinone was Q-9; the phospholipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and three unidentified phospholipids. Phylogenetic trees based on the 16S rRNA, gyrB and rpoD genes' sequences, obtained using three different algorithms, clearly revealed the isolate belonged to the genus Salinicola, and was found to be closely related to Salinicola acroporae JCM 30412, Salinicola socius CGMCC 1.12383 and Salinicola lusitanus CR50. The draft genome was approximately 4.5 Mb in size with 4486 predicted coding sequences, and the G+C content was 62.6 mol%. The maximum values of ANI and dDDH between strain L3 and the three above-mentioned type species were 89.2% and 63.8%, respectively. Differential phenotypic properties, together with the genome analysis, support the view that strain L3 represents a novel species, Salinicola corii sp. nov., with the type strain L3 (=CGMCC 1.17272=KCTC 72572).
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http://dx.doi.org/10.1007/s00284-020-01989-2DOI Listing
August 2020

Preparation, characterization and functional properties of a novel exopolysaccharide produced by the halophilic strain Halomonas saliphila LCB169.

Int J Biol Macromol 2020 Aug 11;156:372-380. Epub 2020 Apr 11.

College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, PR China; Key Laboratory of Leather Chemistry and Engineering (Sichuan University), Ministry of Education, Chengdu 610065, PR China. Electronic address:

A novel exopolysaccharide, designated hsEPS, was successfully prepared from the high-salt-fermented broth of a novel species Halomonas saliphila LCB169 by ethanol precipitation, anion-exchange and gel-filtration chromatography, and its structure was well-characterized by means of chemical and spectral analyses. Results showed that hsEPS was primarily composed of mannose and glucose with a relative weight-average molecular weight of 5.133 × 10 g/mol. It was deduced that the major backbone contained (1→2)-linked α-D-Manp and (1→6)-linked α-D-Manp with branches substituted at C-2 by T-α-D-Manp and at C-6 by the fragment of T-α-D-Manp-(1→2)-α-D-Manp-(1→. A sheet-like structure was observed under high magnification. The water solubility index, water holding capacity, oil holding capacity and foaming capacity of hsEPS were 98.0, 19.3, 1386.7 and 82.2%, respectively. It also exhibited outstanding emulsifying activity against all tested edible oils. Together, the resulted data indicated that hsEPS might serve as an active ingredient in food, cosmetics and detergents.
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http://dx.doi.org/10.1016/j.ijbiomac.2020.04.062DOI Listing
August 2020

Ornithinibacillus caprae sp. nov., a moderate halophile isolated from the hides of a white goat.

Arch Microbiol 2020 Aug 19;202(6):1469-1476. Epub 2020 Mar 19.

College of Biomass Science and Engineering, Sichuan University, Chengdu, People's Republic of China.

A novel Gram-stain-positive, motile, moderate halophile, strain L9, was isolated from hides of white goat in China. The isolate grew optimally at 30 °C, at pH 7 and with 5-10% (w/v) NaCl. The predominant menaquinone was MK-7, and the major cellular fatty acids were identified as iso-C and anteiso-C. The peptidoglycan amino acid type was determined to be A4β, containing L-ornithine and D-aspartic as diagnostic amino acids. The phospholipids were dominated by diphosphatidylglycerol, phosphatidylglycerol, one unidentified aminophospholipid and two unidentified phospholipids. Genome sequencing resulted in a genome size of 4.0 Mbp and a DNA G + C content of 35.9 mol%. Phylogenetic trees based on the 16S rRNA gene sequences showed the isolate to be closely related to Oceanobacillus limi H9B (98.2% similarity) and Ornithinibacillus halophilus G8B (97.5% similarity). The ANI and dDDH values between strain L9 and the closely related species were 69.8-76.1% and 13.0-20.5%, respectively. On the basis of the data presented, strain L9 represents a novel species of the genus Ornithinibacillus, for which the name Ornithinibacillus caprae sp. nov. is proposed. The type strain is L9 (= KCTC 43176 = CGMCC 1.17659).
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http://dx.doi.org/10.1007/s00203-020-01855-6DOI Listing
August 2020

Draft genome sequence of A251, an actinomycetes producing polyketides and nonribosomal polypeptides.

3 Biotech 2020 Feb 30;10(2):79. Epub 2020 Jan 30.

Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, College of Biomass Science and Engineering, Sichuan University, No. 24 South Section 1, Yihuan Road, Chengdu, 610065 People's Republic of China.

In this work, we present the draft genome sequence of A251 consisting of 8,253,402 bp with a G + C content of 71.5 mol%. The genome sequence includes 3 5S rRNA genes, 54 tRNA genes, 28 snRNA genes and 19 CRISPRs in 26 contigs. Using the Rapid Annotation using Subsystem Technology, a total of 7766 coding DNA sequences, which were assigned to 436 subsystems, were found in the genome. And 6743 protein-coding sequences with designated functions were assigned to 19 categories in the Cluster of Orthologous Groups database. The genome contains 20 gene clusters responsible for the synthesis of secondary metabolites, including two type I polyketide synthase (PKS) gene clusters, two type III PKS gene clusters, three nonribosomal peptide synthetase (NRPS) gene clusters and two hybrid PKS/NRPS gene clusters. These results indicate that strain A251 has the ability to produce several nonribosomal polypeptides and diverse polyketides, which was verified by liquid chromatography-mass spectrometry analysis of the extraction from fermentation broth. In addition, lactones, indole and many unknown natural products are present in the metabolites. Bioactivity testing revealed anticancer and antidiabetic activities of the crude extract towards the cancer cell line HepG2. In summary, the genomic sequences and bioactive fermentation products demonstrate the potential of strain A251 in biotechnology.
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http://dx.doi.org/10.1007/s13205-020-2070-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6992827PMC
February 2020

Structural characterization and functional evaluation of a novel exopolysaccharide from the moderate halophile Gracilibacillus sp. SCU50.

Int J Biol Macromol 2020 Jul 19;154:1140-1148. Epub 2019 Nov 19.

College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, PR China; Key Laboratory of Leather Chemistry and Engineering (Sichuan University), Ministry of Education, Chengdu 610065, PR China. Electronic address:

A novel exopolysaccharide (named mhEPS) with a molecular weight of 5.881 × 10 g/mol was isolated from Gracilibacillus sp. SCU50's high-salt fermentation broth by ethanol precipitation, anion-exchange and gel-filtration chromatography before being structurally characterized and functionally evaluated. mhEPS consists of mannose, galactose, glucose and fucose in a molar ratio of 90.81:5.76:2.22:1.21. The backbone of mhEPS was (1→3,6)-linked α-D-mannopyranose residues, branched by single α-D-mannopyranose units attached to the main chain at C-2 position of every residue. The water solubility index, water holding capacity and oil holding capacity of mhEPS were 93.53, 14.89 and 1023.34%, respectively. mhEPS showed to possess good emulsifying activity against all tested substrates, and it could potentially increase the high-salinity tolerance of strain SCU50. The lack of toxicity of mhEPS was also preliminarily determined. Due to the functional properties of mhEPS, it is a good candidate to develop as an active ingredient in food, cosmetics and detergents.
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http://dx.doi.org/10.1016/j.ijbiomac.2019.11.143DOI Listing
July 2020

Genomic characterization of a potentially novel species producing exopolysaccharide.

3 Biotech 2019 Apr 7;9(4):132. Epub 2019 Mar 7.

1Key Laboratory of Leather Chemistry and Engineering, Ministry of Education and College of Light Industry, Textile & Food Engineering, Sichuan University, Chengdu, 610065 People's Republic of China.

Human oral streptococci, particularly the mitis group, often dwell in the upper respiratory tracts, oral mucosa, and tooth surfaces of healthy individuals. In this work, an α-hemolytic strain, designated LQJ-218, was isolated from the human oral cavity and evaluated for its ability to produce exopolysaccharides. Phylogenetic analysis based on 16S rRNA gene sequences showed that this strain is a potentially novel species belonging to the mitis group streptococci. Whole-genome sequence-based analysis indicated that the genome sequence of sp. LQJ-218 was 1,935,194 bp in length, with a mol% G + C content of 40.0, and contained 1897 coding DNA sequences and 91 RNA genes. Furthermore, four biosynthetic gene clusters relevant to exopolysaccharide production were identified in the genome. Both digital DNA-DNA hybridization (yielding a value of 56.60% between strain LQJ-218 and its nearest relative ) and average nucleotide identity analysis (revealing 91.29% identity of LQJ-218 with its nearest relative ) suggested that strain LQJ-218 should be classified as a novel species. This potentially novel strain may possess great potential for contributing to the development of new exopolysaccharides. The present study provides valuable genetic information that may be useful in comparative genomics and biotechnological applications.
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http://dx.doi.org/10.1007/s13205-019-1652-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6405781PMC
April 2019

Planococcus halotolerans sp. nov., isolated from a saline soil sample in China.

Int J Syst Evol Microbiol 2018 Nov 28;68(11):3500-3505. Epub 2018 Sep 28.

1​Key Laboratory of Leather Chemistry and Engineering, Ministry of Education and College of Light Industry, Textile & Food Engineering, Sichuan University, Chengdu 610065, PR China.

A novel Gram-stain-positive, coccoid or short rod-shaped, moderate-orange-pigmented, halotolerant and psychrotolerant bacterium, designated strain SCU63, was isolated from a saline soil sample in China, and characterized by a polyphasic taxonomic approach. 16S rRNA gene sequence similarity of strain SCU63 to species in the genera Planococcus and Planomicrobium ranged from 96.5 to 98.6 %. Phylogenetic trees as well as diagnostic signature nucleotides in the 16S rRNA gene sequence supported the view that this strain should be assigned to the genus Planococcus. Further, average nucleotide identity and digital DNA-DNA hybridization analyses confirmed the separate species status of strain SCU63 relative to the closely related taxa. The isolate grew at 0-40 °C (optimum, 30-35 °C), at pH 6.5-9.0 (pH 7.0-7.5) and in the presence of 0-15 % (w/v) NaCl (3 %). The principal fatty acids were anteiso-C15 : 0, C16 : 1ω7c alcohol, iso-C16 : 0 and iso-C14 : 0, and the dominant isoprenoid quinones were MK-8 and MK-7. The peptidoglycan type was determined to be A4α (l-Lys-d-Glu), and the polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminophospholipid and one unidentified lipid. The DNA G+C content was 44.6 mol%. Based on the genotypic, phenotypic and chemotaxonomic data, strain SCU63 can be classified as a novel species in the genus Planococcus, for which the name Planococcushalotolerans sp. nov. is proposed. The type strain is SCU63 (=CGMCC 1.13628=KCTC 43001).
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http://dx.doi.org/10.1099/ijsem.0.003019DOI Listing
November 2018

Streptomyces dioscori sp. nov., a Novel Endophytic Actinobacterium Isolated from Bulbil of Dioscorea bulbifera L.

Curr Microbiol 2018 Oct 26;75(10):1384-1390. Epub 2018 Jun 26.

Key laboratory of Leather Chemistry and Engineering, Ministry of Education and College of Light Industry, Textile & Food Engineering, Sichuan University, Chengdu, 610065, People's Republic of China.

A novel endophytic actinobacterium strain, A217, was isolated from the bulbil of Dioscorea bulbifera L. Its taxonomic position was characterized using a polyphasic study. Morphological and chemotaxonomic characteristics of strain A217 were consistent with those of members of the genus Streptomyces: long straight to flexuous spore chain; cellular components contained LL-diaminopimelic acid, ribose, and small traces of glucose in whole-cell hydrolysates; MK-9(H) and MK-9(H) as predominant menaquinones. The patterns of major fatty acids are C, anteiso-C, C, iso-C, C ω7c, anteiso-C, and iso-C ω5c. The polar lipids comprised diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol mannoside, and glycolipid, as well as two unidentified phospholipids, one unidentified aminolipid, and one unidentified aminophospholipid. The DNA G + C content of draft genome is 70.7 mol%. Analysis of the 16S rRNA gene sequence and phylogenetic trees revealed that the isolate was most closely related to S. aurantiacus JCM 4453 (99.0%), S. glomeroaurantiacus JCM 4677 (99.0%), and S. tauricus JCM 4837 (98.8%). The DNA-DNA hybridization values between the strain A217 and three reference strains ranged from 34.6% to 51.7%. On the basis of phenotypic and genotypic differentiation from all tested strains, isolate A217 is proposed to represent a novel species of the genus Streptomyces, named Streptomyces dioscori sp. nov. The type strain is A217 (= CGMCC 4.7415 = JCM 32173).
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http://dx.doi.org/10.1007/s00284-018-1534-9DOI Listing
October 2018

Streptomyces populi sp. nov., a novel endophytic actinobacterium isolated from stem of Populus adenopoda Maxim.

Int J Syst Evol Microbiol 2018 Aug 26;68(8):2568-2573. Epub 2018 Jun 26.

1​Key Laboratory of Leather Chemistry and Engineering, Ministry of Education and College of Light Industry, Textile & Food Engineering, Sichuan University, Chengdu 610065, PR China.

A novel endophytic actinobacterium strain, designated A249, was isolated from the stem of Populus adenopoda collected at Mount Qingcheng in south-west China. Its taxonomic position was determined by using a polyphasic approach. The cultural and morphological characteristics of isolate A249 were consistent with members of the genus Streptomyces. Growth occurred at 10-37 °C, pH 6.0-12.0 and in the presence of 0-4 % (w/v) NaCl. Analysis of the 16S rRNA gene sequence and phylogenetic trees showed the closest phylogenetic relatives to strain A249 were Streptomyces shaanxiensis JCM 16925 (98.0 % 16S rRNA gene sequence similarity) and Streptomyces lanatus JCM 4332 (97.9 %). The DNA-DNA hybridization values between the strain A249 and the two reference strains ranged from 41.4 to 49.4 %. The DNA G+C content was 71.7 mol%. The range of average nucleotide identity values was 81.5-86.7 %. Chemical analysis of cellular components indicated that strain A249 contained ll-diaminopimelic acid, xylose and galactose. The predominant menaquinones were MK-9(H6) and MK-9(H8). The polar lipids were diphosphatidylglycerol, phosphatidylinositol mannosides, phosphatidylethanolamine, two unidentified lipids, one unidentified phospholipid, one unidentified aminolipid and one unidentified aminophospholipid. The major fatty acids comprised C16 : 0, iso-C14 : 0, iso-C15 : 0, iso-C16 : 0, anteiso-C15 : 0 and C16 : 1ω7c. On the basis of the phenotypic and genotypic differentiation of the three tested strains, isolate A249 is proposed to represent a novel species of the genus Streptomyces, named Streptomyces populi sp. nov. The type strain is A249 (=CGMCC 4.7417=JCM 32175).
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http://dx.doi.org/10.1099/ijsem.0.002877DOI Listing
August 2018

Streptomyces geranii sp. nov., a novel endophytic actinobacterium isolated from root of Geranium carolinianum L.

Int J Syst Evol Microbiol 2018 Aug 26;68(8):2562-2567. Epub 2018 Jun 26.

1​Key Laboratory of Leather Chemistry and Engineering, Ministry of Education and College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu 610065, PR China.

A novel endophytic actinomycete, designated A301, was isolated from the root of Geranium carolinianum Linn collected from Mount Emei in China and characterized using a polyphasic approach. Growth occurred at 10-37 °C, pH 6-11 and in the presence of 0-5 % NaCl (w/v). Strain A301 contained ll-diaminopimelic acid as the diagnostic diamino acid in the cell-wall peptidoglycan. The whole-cell hydrolysates included galactose and ribose. The predominant menaquinones were MK-9(H6) and MK-9(H8). The major cellular fatty acids were C15 : 0, C16 :  0, anteiso-C15 : 0 and iso-C16 : 0. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, two unidentified phospholipids, three unidentified lipids and two unidentified aminophospholipids. Strain A301 shared the highest 16S rRNA gene sequence similarity to Streptomyces cinereorubersubsp. fructofermentans NBRC 15396 (98.1 %) and Streptomyces turgidiscabies ATCC 700248 (98.1 %). The DNA-DNA relatedness values between strain A301 and the two above-mentioned members of the genus Streptomyces were 42.6 % and 47.2 %, respectively. The G+C content of the DNA was 70.5 mol%. On the basis of the polyphasic approach and DNA-DNA hybridization data, strain A301 represents a novel species within the genus Streptomyces, for which the name Streptomyces geranii sp. nov. is proposed. The type strain is A301 (=CGMCC 4.7422=JCM 32177).
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http://dx.doi.org/10.1099/ijsem.0.002876DOI Listing
August 2018

Biosynthesis, characterization and antimicrobial activity of silver nanoparticles by a halotolerant SCU-L.

Prep Biochem Biotechnol 2018 5;48(7):582-588. Epub 2018 Jun 5.

a Key Laboratory of Leather Chemistry and Engineering, Ministry of Education and College of Light Industry, Textile & Food Engineering , Sichuan University , Chengdu , PR China.

We have conducted a thorough study on extracellular biosynthesis of silver nanoparticles (AgNPs) by a halotolerant bacterium SCU-L, which was identified by 16S rRNA gene sequencing analysis. This strain was selected during an ongoing research programme aimed at finding a novel biological method for green nanosynthetic routes using the extremophiles in unexplored hypersaline habitats. The biosynthesized AgNPs were characterized and analyzed with UV-vis spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, atomic force microscopy and X-ray diffraction. Further, the AgNPs were found to be spherical in shape with an average particle size of about 5.1 nm, and it was stable in aqueous solution for three months period of storage at room temperature under dark condition. Also, the synthesized AgNPs significantly presented antimicrobial activity against , , and . The above results suggested that the present work may provide a valuable reference and theoretical basis for further exploration on microbial biosynthesis of AgNPs by halotolerant bacteria.
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http://dx.doi.org/10.1080/10826068.2018.1476880DOI Listing
June 2018

Halomonas saliphila sp. nov., a moderately halophilic bacterium isolated from a saline soil.

Int J Syst Evol Microbiol 2018 Apr 19;68(4):1153-1159. Epub 2018 Feb 19.

Key Laboratory of Leather Chemistry and Engineering, Ministry of Education and College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu 610065, PR China.

A novel, Gram-stain-negative, aerobic, rod-shaped, motile and moderately halophilic bacterium, designated strain LCB169, was isolated from a saline soil sample from Gansu Province, PR China. The cells of LCB169 grew at 10-52 °C (optimum 30 °C), at pH 6.0-10.0 (optimum pH 8.0) and in the presence of 0-17 % (w/v) NaCl (optimum 10-15 %). Phylogenetic analysis based on 16S rRNA gene sequences and concatenated 16S rRNA, gyrB and rpoD genes sequences revealed that LCB169 represented a member of the genus Halomonas in the class Gammaproteobacteria. The most closely related species were Halomonas daqingensis DQD2-30 (98.0 % 16S rRNA gene sequence similarity), Halomonas kenyensis AIR-2 (97.8 %) and Halomonas desiderata FB2 (97.5 %). DNA-DNA relatedness values between LCB169 and H. daqingensis CGMCC 1.6443, H. desiderata DSM 9502 and H. kenyensis DSM 17331 were 33, 35 and 38 %, respectively. The polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and three unidentified phospholipids. The major fatty acids were C18 : 1ω7c, C16 : 0, C16 : 1ω7c and C12 : 0 3-OH. The genomic DNA G+C content was 66.1 mol% and the predominant respiratory quinone was Q-9. On the basis of the results of phenotypic, phylogenetic and chemotaxonomic analyses and DNA-DNA hybridization relatedness values, LCB169 is considered to represent a novel species of the genus Halomonas, for which the name Halomonas saliphila sp. nov. is proposed. The type strain is LCB169 (=CGMCC 1.15818=KCTC 52618).
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http://dx.doi.org/10.1099/ijsem.0.002644DOI Listing
April 2018

Ornithinibacillus salinisoli sp. nov., a moderately halophilic bacterium isolated from a saline-alkali soil.

Int J Syst Evol Microbiol 2018 Mar 22;68(3):769-775. Epub 2018 Jan 22.

Key Laboratory of Leather Chemistry and Engineering, Ministry of Education and College of Light Industry, Textile & Food Engineering, Sichuan University, Chengdu 610065, PR China.

A taxonomic study was performed on strain LCB256, which was isolated from a saline-alkali soil sample taken from northwestern China. Cells of strain LCB256 were Gram-stain-positive, aerobic, rod-shaped and grew at 3-17 % (w/v) NaCl (optimum 10-15 %), 10-52 °C (optimum 25-30 °C) and pH 7.0-9.0 (optimum 8.0). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain LCB256 was most closely related to the two genera of Ornithinibacillus and Oceanobacillus, showing highest sequence similarity to Oceanobacillus limi KCTC 13823 (97.8 %) and Ornithinibacillus bavariensis WSBC 24001 (97.2 %). The peptidoglycan amino acid type was found to be A4β and the major respiratory quinone was determined to be MK-7. The polar lipid profile of strain LCB256 contained diphosphatidylglycerol, phosphatidylglycerol, one unidentified phospholipid and two unidentified aminolipids. The dominant cellular fatty acids were anteiso-C15 : 0 and iso-C15 : 0. The G+C content of genomic DNA was 39.3 mol%. DNA-DNA relatedness values between strain LCB256 and Ornithinibacillus halophilus KCTC 13822 and Oceanobacillus limi KCTC 13823 were 46.2 and 34.8 %, respectively. Based on this polyphasic taxonomic study, a novel species of the genus Ornithinibacillus, Ornithinibacillussalinisoli sp. nov. is proposed. The type strain is LCB256 (=CGMCC 1.15809=KCTC 33862).
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http://dx.doi.org/10.1099/ijsem.0.002580DOI Listing
March 2018

Screening cyhalothrin degradation strains from locust epiphytic bacteria and studying Paracoccus acridae SCU-M53 cyhalothrin degradation process.

Environ Sci Pollut Res Int 2018 Apr 9;25(12):11505-11515. Epub 2018 Feb 9.

Key Laboratory of Leather Chemistry and Engineering(Sichuan University), Ministry of Education and College of Light Industry, Textile & Food Engineering, Sichuan University, Chengdu, 610065, People's Republic of China.

All locust epiphytic bacteria were screened and a total of 62 epiphytic bacteria were obtained from samples of Acrida cinerea. Via phylogenetic analysis, the 62 epiphytic bacteria were allocated to 27 genera, 18 families, 13 orders, six classes, and four phylums. Then, cyhalothrin degradation experiments were conducted, and the 10 strains that degraded more than 30% cyhalothrin and Paracoccus acridae SCU-M53 showed the highest cyhalothrin degradation rate of 70.5%. Furthermore, Paracoccus acridae SCU-M53 was selected for optimal cyhalothrin biodegradation conditions via the response surface method (Design-Expert). Under the optimum conditions (28 °C, 75 mg/L, and 180 rpm), the cyhalothrin degradation rate reached 79.84% after 2 days. This suggests the possibility that isolating biodegradation cyhalothrin strains from Acrida cinerea is feasible.
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http://dx.doi.org/10.1007/s11356-018-1410-yDOI Listing
April 2018

Planococcus salinus sp. nov., a moderately halophilic bacterium isolated from a saline-alkali soil.

Int J Syst Evol Microbiol 2018 Feb 4;68(2):589-595. Epub 2018 Jan 4.

Key Laboratory of Leather Chemistry and Engineering, Ministry of Education and College of Light Industry, Textile & Food Engineering, Sichuan University, Chengdu 610065, PR China.

A novel aerobic, Gram-stain-positive, motile, moderately halophilic and coccoid bacterial strain, designated LCB217, was isolated from a saline-alkali soil in north-western China and identified using a polyphasic taxonomic approach. Growth occurred with 3-15 % (w/v) NaCl (optimum 3-5 %), at 10-45 °C (optimum 30 °C) and at pH 7.0-9.0 (optimum pH 9.0). Strain LCB217 contained MK-7 and MK-8 as the predominant menaquinones and anteiso-C15 : 0, iso-C14 : 0 and iso-C16 : 0 as the major fatty acids. The polar lipids from strain LCB217 consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, one unidentified phospholipid, one unidentified aminophospholipid and one unidentified lipid. The peptidoglycan type was A4α (l-Lys-d-Glu). Phylogenetic analysis of the 16S rRNA gene sequence showed that strain LCB217 belonged to the genus Planococcus and was closely related to the type strains Planococcus plakortidis AS/ASP6 (II) (98.2 % similarity), Planococcus maitriensis S1 (97.7 %) and Planococcus salinarum ISL-16 (97.2 %). The G+C content of the genomic DNA was 49.4 mol%. DNA-DNA relatedness values between strain LCB217 andPlanococcusplakortidis AS/ASP6 (II), Planococcusmaitriensis S1 andPlanococcussalinarum ISL-16 were 29.5, 38.1 and 39.5 %, respectively. On the basis of the phenotypic, phylogenetic and genomic data, strain LCB217 represents a novel species of the genus Planococcus, for which the name Planococcus salinus sp. nov. is proposed. The type strain is LCB217 (=CGMCC 1.15685=KCTC 33861).
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http://dx.doi.org/10.1099/ijsem.0.002548DOI Listing
February 2018

Paracoccusacridae sp. nov., isolated from the insect Acrida cinerea living in deserted cropland.

Int J Syst Evol Microbiol 2016 Sep 6;66(9):3492-3497. Epub 2016 Jun 6.

Key Laboratory of Leather Chemistry and Engineering (Sichuan University), Ministry of Education and College of Light Industry, Textile & Food Engineering, Sichuan University, Chengdu 610065, PR China.

A Gram-stain-negative, aerobic, rod-shaped, non-motile bacterial strain, designated SCU-M53T, was isolated from the insect Acrida cinerea. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain SCU-M53T belonged to the genus Paracoccus, having Paracoccus chinensisNBRC 104937T (97.04 % 16S rRNA gene sequence similarity) and Paracoccus niistensis KCTC 22789T (96.70 %) as the most closely related phylogenetic neighbours. Growth occurred at 10-40 °C (optimum 25-30 °C), pH 5.0-10.0 (optimum pH 6.5-7.5) and with 0-4 % (w/v) NaCl (optimum 0-1 % NaCl). The fatty acids of strain SCU-M53T were C18 : 1ω7c, C18 : 0, C16 : 0, C14 : 0 3-OH, C14 : 0 and C10 : 0 3-OH. The polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine, an unknown aminolipid, two unknown phospholipids and two unknown lipids. The isoprenoid quinone was ubiquinone-10. The DNA G+C content was 60.6 mol%. Strain SCU-M53T exhibited 36.5 and 28.6 % DNA-DNA relatedness to P. chinensis NBRC 104937T and P. niistensis KCTC 22789T, respectively. According to these results, strain SCU-M53T represents a novel species of the genus Paracoccus, for which the name Paracoccus acridae sp. nov. is proposed. The type strain is SCU-M53T (=KCTC 42932T=CGMCC 1.15419T).
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http://dx.doi.org/10.1099/ijsem.0.001222DOI Listing
September 2016
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