Publications by authors named "Zainul Akmar Zakaria"

12 Publications

  • Page 1 of 1

Characterization and antiinflammatory properties of fractionated pyroligneous acid from palm kernel shell.

Environ Sci Pollut Res Int 2020 May 16. Epub 2020 May 16.

School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310, Johor Bahru, Johor, Malaysia.

Pyroligneous acid (PA) obtained from slow pyrolysis of palm kernel shell (PKS) has high total phenolic contents and exhibits various biological activities including antioxidant, antibacterial and antifungal. In this study, PA obtained using slow pyrolysis method and fractionated using column chromatography was characterized (chemical and antioxidative properties) and investigated for its cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) inhibition activities using the in vitro and in silico approaches. The F PA fraction exhibited highest total phenolic content of 181.75 ± 17.0 μg/mL. Fraction F showed ferric reducing antioxidant power (FRAP) (331.80 ± 4.60 mg TE/g) and IC of 18.56 ± 0.01 μg/mL towards COX-2 and 5.25 ± 0.03 μg/mL towards the 5-LOX enzymes, respectively. Molecular docking analysis suggested favourable binding energy for all chemical compounds present in fraction F, notably 1-(2,4,6-trihydroxyphenyl)-2-pentanone, towards both COX-2 (- 6.9 kcal/mol) and 5-LOX (- 6.4 kcal/mol) enzymes. As a conclusion, PA from PKS has the potential to be used as an alternative antioxidant and antiinflammatory agents which is biodegradable and a more sustainable supply of raw materials.
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http://dx.doi.org/10.1007/s11356-020-09209-xDOI Listing
May 2020

Preparation, characterization, and dye removal study of activated carbon prepared from palm kernel shell.

Environ Sci Pollut Res Int 2018 Feb 8;25(6):5076-5085. Epub 2017 Apr 8.

Institute of Bioproduct Development IBD, Universiti Teknologi Malaysia, 81310 UTM, Johor Bahru, Johor, Malaysia.

Palm oil mill wastes (palm kernel shell (PKS)) were used to prepare activated carbons, which were tested in the removal of colorants from water. The adsorbents were prepared by 1-h impregnation of PKS with ZnCl as the activating agent (PKS:ZnCl mass ratios of 1:1 and 2:1), followed by carbonization in autogenous atmosphere at 500 and 550 °C during 1 h. The characterization of the activated carbons included textural properties (porosity), surface chemistry (functional groups), and surface morphology. The dye removal performance of the different activated carbons was investigated by means of the uptake of methylene blue (MB) in solutions with various initial concentrations (25-400 mg/L of MB) at 30 °C, using a 0.05-g carbon/50-mL solution relationship. The sample prepared with 1:1 PKS:ZnCl and carbonized at 550 °C showed the highest MB adsorption capacity (maximum uptake at the equilibrium, q  = 225.3 mg MB / g adsorbent), resulting from its elevated specific surface area (BET, 1058 m/g) and microporosity (micropore surface area, 721 m/g). The kinetic experiments showed that removals over 90% of the equilibrium adsorptions were achieved after 4-h contact time in all the cases. The study showed that palm oil mill waste biomass could be used in the preparation of adsorbents efficient in the removal of colorants in wastewaters.
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http://dx.doi.org/10.1007/s11356-017-8975-8DOI Listing
February 2018

Reactivity of phenolic compounds towards free radicals under in vitro conditions.

J Food Sci Technol 2015 Sep 8;52(9):5790-8. Epub 2015 Jan 8.

Institute of Bioproduct Development, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor Malaysia.

The free radical scavenging activity and reducing power of 16 phenolic compounds including four hydroxycinnamic acid derivatives namely ferulic acid, caffeic acid, sinapic acid and p-coumaric acid, benzoic acid and its derivatives namely protocatechuic acid, gallic acid and vanillic acid, benzene derivatives namely vanillin, vanillyl alcohol, veratryl alcohol, veratraldehyde, pyrogallol, guaiacol and two synthetic antioxidants, butylated hydroxy anisole (BHA) and propyl gallate were evaluated using 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH(•)), 2,2'-Azinobis-3- ethylbenzothiazoline-6-sulfonic acid radical (ABTS(+•)), Hydroxyl radical ((•)OH) and Superoxide radical (O2 (•-)) scavenging assays and reduction potential assay. By virtue of their hydrogen donating ability, phenolic compounds with multiple hydroxyl groups such as protocatechuic acid, pyrogallol, caffeic acid, gallic acid and propyl gallate exhibited higher free radical scavenging activity especially against DPPH(•) and O2 (•-). The hydroxylated cinnamates such as ferulic acid and caffeic acid were in general better scavengers than their benzoic acid counter parts such as vanillic acid and protocatechuic acid. All the phenolic compounds tested exhibited more than 85 % scavenging due to the high reactivity of the hydroxyl radical. Phenolic compounds with multiple hydroxyl groups also exhibited high redox potential. Exploring the radical scavenging and reducing properties of antioxidants especially those which are found naturally in plant sources are of great interest due to their protective roles in biological systems.
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http://dx.doi.org/10.1007/s13197-014-1704-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4554629PMC
September 2015

Optimization of culture conditions for flexirubin production by Chryseobacterium artocarpi CECT 8497 using response surface methodology.

Acta Biochim Pol 2015 15;62(2):185-90. Epub 2015 May 15.

Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia.

Flexirubins are the unique type of bacterial pigments produced by the bacteria from the genus Chryseobacterium, which are used in the treatment of chronic skin disease, eczema etc. and may serve as a chemotaxonomic marker. Chryseobacterium artocarpi CECT 8497, an yellowish-orange pigment producing strain was investigated for maximum production of pigment by optimizing medium composition employing response surface methodology (RSM). Culture conditions affecting pigment production were optimized statistically in shake flask experiments. Lactose, l-tryptophan and KH2PO4 were the most significant variables affecting pigment production. Box Behnken design (BBD) and RSM analysis were adopted to investigate the interactions between variables and determine the optimal values for maximum pigment production. Evaluation of the experimental results signified that the optimum conditions for maximum production of pigment (521.64 mg/L) in 50 L bioreactor were lactose 11.25 g/L, l-tryptophan 6 g/L and KH2PO4 650 ppm. Production under optimized conditions increased to 7.23 fold comparing to its production prior to optimization. Results of this study showed that statistical optimization of medium composition and their interaction effects enable short listing of the significant factors influencing maximum pigment production from Chryseobacterium artocarpi CECT 8497. In addition, this is the first report optimizing the process parameters for flexirubin type pigment production from Chryseobacterium artocarpi CECT 8497.
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http://dx.doi.org/10.18388/abp.2014_870DOI Listing
April 2016

Pyroligneous acid-the smoky acidic liquid from plant biomass.

Appl Microbiol Biotechnol 2015 Jan 3;99(2):611-22. Epub 2014 Dec 3.

Institute of Bioproduct Development, Universiti Teknologi Malaysia (UTM), 81310, Johor Bahru, Johor, Malaysia,

Pyroligneous acid (PA) is a complex highly oxygenated aqueous liquid fraction obtained by the condensation of pyrolysis vapors, which result from the thermochemical breakdown or pyrolysis of plant biomass components such as cellulose, hemicellulose, and lignin. PA produced by the slow pyrolysis of plant biomass is a yellowish brown or dark brown liquid with acidic pH and usually comprises a complex mixture of guaiacols, catechols, syringols, phenols, vanillins, furans, pyrans, carboxaldehydes, hydroxyketones, sugars, alkyl aryl ethers, nitrogenated derivatives, alcohols, acetic acid, and other carboxylic acids. The phenolic components, namely guaiacol, alkyl guaiacols, syringol, and alkyl syringols, contribute to the smoky odor of PA. PA finds application in diverse areas, as antioxidant, antimicrobial, antiinflammatory, plant growth stimulator, coagulant for natural rubber, and termiticidal and pesticidal agent; is a source for valuable chemicals; and imparts a smoky flavor for food.
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http://dx.doi.org/10.1007/s00253-014-6242-1DOI Listing
January 2015

Chryseobacterium artocarpi sp. nov., isolated from the rhizosphere soil of Artocarpus integer.

Int J Syst Evol Microbiol 2014 Sep 23;64(Pt 9):3153-3159. Epub 2014 Jun 23.

Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia.

A bacterial strain, designated UTM-3(T), isolated from the rhizosphere soil of Artocarpus integer (cempedak) in Malaysia was studied to determine its taxonomic position. Cells were Gram-stain-negative, non-spore-forming rods, devoid of flagella and gliding motility, that formed yellow-pigmented colonies on nutrient agar and contained MK-6 as the predominant menaquinone. Comparative analysis of the 16S rRNA gene sequence of strain UTM-3(T) with those of the most closely related species showed that the strain constituted a distinct phyletic line within the genus Chryseobacterium with the highest sequence similarities to Chryseobacterium lactis NCTC 11390(T), Chryseobacterium viscerum 687B-08(T), Chryseobacterium tructae 1084-08(T), Chryseobacterium arthrosphaerae CC-VM-7(T), Chryseobacterium oncorhynchi 701B-08(T), Chryseobacterium vietnamense GIMN1.005(T), Chryseobacterium bernardetii NCTC 13530(T), Chryseobacterium nakagawai NCTC 13529(T), Chryseobacterium gallinarum LMG 27808(T), Chryseobacterium culicis R4-1A(T), Chryseobacterium flavum CW-E2(T), Chryseobacterium aquifrigidense CW9(T), Chryseobacterium ureilyticum CCUG 52546(T), Chryseobacterium indologenes NBRC 14944(T), Chryseobacterium gleum CCUG 14555(T), Chryseobacterium jejuense JS17-8(T), Chryseobacterium oranimense H8(T) and Chryseobacterium joostei LMG 18212(T). The major whole-cell fatty acids were iso-C15 : 0 and iso-C17 : 1ω9c, followed by summed feature 4 (iso-C15 : 0 2-OH and/or C16 : 1ω7t) and iso-C17 : 0 3-OH, and the polar lipid profile consisted of phosphatidylethanolamine and several unknown lipids. The DNA G+C content strain UTM-3(T) was 34.8 mol%. On the basis of the phenotypic and phylogenetic evidence, it is concluded that the isolate represents a novel species of the genus Chryseobacterium, for which the name Chryseobacterium artocarpi sp. nov. is proposed. The type strain is UTM-3(T) ( = CECT 8497(T) = KCTC 32509(T)).
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http://dx.doi.org/10.1099/ijs.0.063594-0DOI Listing
September 2014

Isotherm kinetics of Cr(III) removal by non-viable cells of Acinetobacter haemolyticus.

Colloids Surf B Biointerfaces 2012 Jun 22;94:362-8. Epub 2012 Feb 22.

Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia.

The potential use of non-viable biomass of a Gram negative bacterium i.e. Acinetobacter haemolyticus to remove Cr(III) species from aqueous environment was investigated. Highest Cr(III) removal of 198.80 mg g(-1) was obtained at pH 5, biomass dosage of 15 mg cell dry weight, initial Cr(III) of 100 mg L(-1) and 30 min of contact time. The Langmuir and Freundlich models fit the experimental data (R(2)>0.95) while the kinetic data was best described using the pseudo second-order kinetic model (R(2)>0.99). Cr(III) was successfully recovered from the bacterial biomass using either 1M of CH(3)COOH, HNO(3) or H(2)SO(4) with 90% recovery. TEM and FTIR suggested the involvement of amine, carboxyl, hydroxyl and phosphate groups during the biosorption of Cr(III) onto the cell surface of A. haemolyticus. A. haemolyticus was also capable to remove 79.87 mg g(-1) Cr(III) (around 22.75%) from raw leather tanning wastewater. This study demonstrates the potential of using A. haemolyticus as biosorbent to remove Cr(III) from both synthetic and industrial wastewater.
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http://dx.doi.org/10.1016/j.colsurfb.2012.02.016DOI Listing
June 2012

Bacterial reduction of Cr(VI) at technical scale--the Malaysian experience.

Appl Biochem Biotechnol 2012 Jul 22;167(6):1641-52. Epub 2012 Feb 22.

Institute of Bioproduct Development, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia.

The bacterial reduction of Cr(VI) from industrial wastewater was evaluated using a 2.0-m(3) bioreactor. Liquid pineapple waste was used as a nutrient for the biofilm community formed inside the bioreactor. The use of rubber wood sawdust as packing material was able to immobilize more than 10(6) CFU mL(-1) of Acinetobacter haemolyticus cells after 3 days of contact time. Complete reduction of 15-240 mg L(-1) of Cr(VI) was achieved even after 3 months of bioreactor operation. Cr(VI) was not detected in the final effluent fraction indicating complete removal of Cr from solution from the flocculation/coagulation step and the unlikely re-oxidation of Cr(III) into Cr(VI). Impatiens balsamina L. and Gomphrena globosa L. showed better growth in the presence of soil-sludge mixture compared to Coleus scutellarioides (L.) Benth. Significant amounts of Cr accumulated at different sections of the plants indicate its potential application in Cr phytoremediation effort. The bacterial-based system was also determined not to be detrimental to human health based on the low levels of Cr detected in the hair and nail samples of the plant operators. Thus, it can be said that bacterial-based Cr(VI) treatment system is a feasible alternative to the conventional system especially for lower Cr(VI) concentrations, where sludge generated can be used as growth supplement for ornamental plant as well as not detrimental to the health of the workers.
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http://dx.doi.org/10.1007/s12010-012-9608-9DOI Listing
July 2012

Production and characterization of violacein by locally isolated Chromobacterium violaceum grown in agricultural wastes.

Appl Biochem Biotechnol 2012 Jul 26;167(5):1220-34. Epub 2012 Jan 26.

Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, Johor, Malaysia.

The present work highlighted the production of violacein by the locally isolated Chromobacterium violaceum (GenBank accession no. HM132057) in various agricultural waste materials (sugarcane bagasse, solid pineapple waste, molasses, brown sugar), as an alternative to the conventional rich medium. The highest yield for pigment production (0.82 g L⁻¹) was obtained using free cells when grown in 3 g of sugarcane bagasse supplemented with 10% (v/v) of L-tryptophan. A much lower yield (0.15 g L⁻¹) was obtained when the cells were grown either in rich medium (nutrient broth) or immobilized onto sugarcane bagasse. Violacein showed similar chemical properties as other natural pigments based on the UV-Vis, Fourier transform infrared spectroscopy, thin-layer chromatography, nuclear magnetic resonance, and mass spectrometry analysis. The pigment is highly soluble in acetone and methanol, insoluble in water or non-polar organic solvents, and showed good stability between pH 5-9, 25-100 °C, in the presence of light metal ions and oxidant such as H₂O₂. However, violacein would be slowly degraded upon exposure to light. This is the first report on the use of cheap and easily available agricultural wastes as growth medium for violacein-producing C. violaceum.
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http://dx.doi.org/10.1007/s12010-012-9553-7DOI Listing
July 2012

Pilot-scale removal of chromium from industrial wastewater using the ChromeBac system.

Bioresour Technol 2010 Jun 25;101(12):4371-8. Epub 2010 Feb 25.

Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia.

The enzymatic reduction of Cr(VI) to Cr(III) by Cr(VI) resistant bacteria followed by chemical precipitation constitutes the ChromeBac system. Acinetobacter haemolyticus was immobilized onto carrier material inside a 0.2m(3) bioreactor. Neutralized electroplating wastewater with Cr(VI) concentration of 17-81 mg L(-1) was fed into the bioreactor (0.11-0.33 m(3)h(-1)). Complete Cr(VI) reduction to Cr(III) was obtained immediately after the start of bioreactor operation. Together with the flocculation, coagulation and filtration, outflow concentration of less than 0.02 mg Cr(VI)L(-1) and 1mg total CrL(-1) were always obtained. Performance of the bioreactor was not affected by fluctuations in pH (6.2-8.4), Cr(VI) (17-81 mg L(-1)), nutrient (liquid pineapple waste, 1-20%v/v) and temperature (30-38 degrees C). Standby periods of up to 10 days can be tolerated without loss in activity. A robust yet effective biotechnology to remove chromium from wastewater is thus demonstrated.
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http://dx.doi.org/10.1016/j.biortech.2010.01.106DOI Listing
June 2010

Biological detoxification of Cr(VI) using wood-husk immobilized Acinetobacter haemolyticus.

J Hazard Mater 2007 Sep 15;148(1-2):164-71. Epub 2007 Feb 15.

Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia.

Acinetobacter haemolyticus, a Gram-negative aerobic locally isolated bacterium, immobilized on wood-husk showed the ability to detoxify Cr(VI) to Cr(III). Wood-husk, a natural cellulose-based support material, packed in an upward-flow column was used as support material for bacterial attachment. Around 97% of the Cr(VI) in wastewater containing 15 mg L(-1) of Cr(VI) was reduced at a flow rate of 8.0 mL min(-1). The wastewater containing Cr(VI) was added with liquid pineapple wastewater as nutrient source for the bacteria. Electron microscopic examinations of the wood-husk after 42 days of column operation showed gradual colonization of the wood-husk by bacterial biofilm. The use of 0.1% (v/v) formaldehyde as a disinfecting agent inhibited growth of bacteria present in the final wastewater discharge. This finding is important in view of the ethical code regarding possible introduction of exogenous bacterial species into the environment.
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http://dx.doi.org/10.1016/j.jhazmat.2007.02.029DOI Listing
September 2007

Hexavalent chromium reduction by Acinetobacter haemolyticus isolated from heavy-metal contaminated wastewater.

J Hazard Mater 2007 Jul 30;146(1-2):30-8. Epub 2006 Nov 30.

Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia.

Possible application of a locally isolated environmental isolate, Acinetobacter haemolyticus to remediate Cr(VI) contamination in water system was demonstrated. Cr(VI) reduction by A. haemolyticus seems to favour the lower concentrations (10-30 mg/L). However, incomplete Cr(VI) reduction occurred at 70-100 mg/L Cr(VI). Initial specific reduction rate increased with Cr(VI) concentrations. Cr(VI) reduction was not affected by 1 or 10 mM sodium azide (metabolic inhibitor), 10 mM of PO(4)3-, SO4(2-), SO(3)2-, NO3- or 30 mg/L of Pb(II), Zn(II), Cd(II) ions. However, heat treatment caused significant dropped in Cr(VI) reduction to less than 20% only. A. haemolyticus cells loses its shape and size after exposure to 10 and 50 mg Cr(VI)/L as revealed from TEM examination. The presence of electron-dense particles in the cytoplasmic region of the bacteria suggested deposition of chromium in the cells.
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http://dx.doi.org/10.1016/j.jhazmat.2006.11.052DOI Listing
July 2007