Gyeongsangnam do Agricultural Research and Extension Service

Chinju, South Korea

Gyeongsangnam do Agricultural Research and Extension Service

Chinju, South Korea

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Haque M.A.,Gyeongsang National University | Haque M.A.,Gyeongnam National University of Science and Technology | Barman D.N.,Gyeongsang National University | Kim M.K.,Gyeongsangnam do Agricultural Research and Extension Service | And 2 more authors.
Journal of the Science of Food and Agriculture | Year: 2016

BACKGROUND: Imperata cylindrica is being considered as a biomass candidate for bioethanol. This work aimed to evaluate a mild alkali pretreatment effect on the Imperata recalcitrant structure. Therefore, varied concentrations of NaOH (0, 7.5, 15, 20, and 25gL-1) were applied as treatments to Imperata at 105°C for 10min. RESULTS: Scanning electron microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy studies revealed that 20 to 25gL-1 NaOH-treated Imperata exposed amorphous cellulose on surface granules composed of lignin, waxes, and partly hemicelluloses were abolished due to the comprehensive disruption of the linkages between lignin and carbohydrates. The cellulose crystalline index was increased with 7.5 to 20gL-1 NaOH treatments and reduced with a 25gL-1 NaOH treatment. In fact, the cellulose content in solids increased with the increasing NaOH concentration and was estimated to be 720 and 740gkg-1 for the 20 and 25gL-1 NaOH treatments, respectively. The yield of the reducing sugar was obtained 805 and 813mgg-1 from 20 and 25gL-1 NaOH-treated Imperata, respectively. CONCLUSION: Considering the cost of pretreatment, the 20gL-1 NaOH treatment is judged to be effective for disrupting Imperata recalcitrance in this pretreatment regime. © 2015 Society of Chemical Industry.


PubMed | Gyeongsang National University, Gyeongsangnam do Agricultural Research and Extension Service and Gyeongnam National University of Science and Technology
Type: Journal Article | Journal: Journal of the science of food and agriculture | Year: 2016

Imperata cylindrica is being considered as a biomass candidate for bioethanol. This work aimed to evaluate a mild alkali pretreatment effect on the Imperata recalcitrant structure. Therefore, varied concentrations of NaOH (0, 7.5, 15, 20, and 25gL(-1) ) were applied as treatments to Imperata at 105C for 10min.Scanning electron microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy studies revealed that 20 to 25gL(-1) NaOH-treated Imperata exposed amorphous cellulose on surface granules composed of lignin, waxes, and partly hemicelluloses were abolished due to the comprehensive disruption of the linkages between lignin and carbohydrates. The cellulose crystalline index was increased with 7.5 to 20gL(-1) NaOH treatments and reduced with a 25gL(-1) NaOH treatment. In fact, the cellulose content in solids increased with the increasing NaOH concentration and was estimated to be 720 and 740gkg(-1) for the 20 and 25gL(-1) NaOH treatments, respectively. The yield of the reducing sugar was obtained 805 and 813mgg(-1) from 20 and 25gL(-1) NaOH-treated Imperata, respectively.Considering the cost of pretreatment, the 20gL(-1) NaOH treatment is judged to be effective for disrupting Imperata recalcitrance in this pretreatment regime.


Haque M.A.,Gyeongsang National University | Barman D.N.,Gyeongsang National University | Kang T.H.,Gyeongsang National University | Kim M.K.,Gyeongsangnam do Agricultural Research and Extension Service | And 3 more authors.
Journal of Microbiology and Biotechnology | Year: 2012

This work was conducted to evaluate the effect of dilute sodium hydroxide (NaOH) on barley straw at boiling temperature and fractionation of its biomass components into lignin, hemicellulose, and reducing sugars. To this end, various concentrations of NaOH (0.5% to 2%) were applied for pretreatment of barley straw at 105°C for 10 min. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and Fourier transform infrared (FTIR) spectroscopy studies revealed that 2% NaOHpretreated barley straw exposed cellulose fibers on which surface granules were abolished due to comprehensive removal of lignin and hemicellulose. The X-ray diffractometer (XRD) result showed that the crystalline index was increased with increased concentration of NaOH and found a maximum 71.5% for 2% NaOH-pretreated sample. The maximum removal of lignin and hemicellulose was 84.8% and 79.5% from 2% NaOH-pretreated liquor, respectively. Reducing sugar yield was 86.5% from 2% NaOH-pretreated sample using an enzyme dose containing 20 FPU of cellulase, 40 IU of β-glucosidase, and 4 FXU of xylanase/g substrate. The results of this study suggest that it is possible to produce the bioethanol precursor from barley straw using 2% NaOH at boiling temperature. © The Korean Society for Microbiology and Biotechnology.


Barman D.N.,Gyeongsang National University | Haque M.A.,Gyeongsang National University | Kang T.H.,Gyeongsang National University | Kim M.K.,Gyeongsangnam do Agricultural Research and Extension Service | And 3 more authors.
Bioscience, Biotechnology and Biochemistry | Year: 2012

We evaluated the effect of dilute sodium hydroxide (NaOH) on wheat straw at boiling temperature for removing lignin and increasing the yield of reducing sugar. Various concentrations of NaOH (0.5% to 2%) were used for pretreating wheat straw at 105 °C for 10 min. Scanning electron microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy studies revealed that the 2% NaOH-pretreated sample exposed more cellulose fiber. The maximum respective removal of lignin and hemicellulose was 70.3% and 68.2% from the 2% NaOH-pretreated liquor. The reducing sugar yield was 84.6% using an enzyme dose containing 20 FPU of cellulase, 40 IU of β-glucosidase and 4 FXU of xylanase/g of substrate. However, 2% NaOH-treated wheat straw had the lowest crystalline index of 52.5%, due to destructured cellulose fibers. The results indicate the effectiveness of producing the bioethanol precursor from wheat straw by using 2% NaOH at boiling temperature.


Barman D.N.,Gyeongsang National University | Haque M.A.,Gyeongsang National University | Islam S.M.A.,Patuakhali Science and Technology University | Yun H.D.,Gyeongsang National University | Kim M.K.,Gyeongsangnam do Agricultural Research and Extension Service
Ecotoxicology and Environmental Safety | Year: 2014

Chlorpyrifos is an organophosphate pesticide that has adverse effect on animals and plants. We isolated endophytic bacterial strain, Pseudomonas sp. BF1-3, from balloon flower root which can hydrolyze chlorpyrifos. A gene (ophB) encoding a protein involved in chlorpyrifos degradation from this strain was cloned into Escherichia coli DH5α for confirming enzyme activity. After sequencing, total 1024bp nucleotide sequences were found in the open reading frame of ophB. The chlorpyrifos degradation patterns by E. coli DH5α (ophB) were observed. During incubation in minimal salt (M9) medium supplemented with chlorpyrifos (100mgL-1), the E. coli DH5α harboring ophB degraded about 97% initial chlorpyrifos (100mgL-1) and accumulated 86mgL-1 3,5,6-trichloro-2-pyridinol (TCP) within 9 days. In addition, optical density (OD) of E. coli DH5α (ophB) culture at 600nm was increased from 0.172 to 1.118 within 2 days of inoculation in the chlorpyrifos supplemented M9 medium. The estimated molecular weight of purified OphB protein was determined to be 31.4kDa by SDS-PAGE. The OphB enzyme was most active at pH 8 and an optimal temperature around 35°C. These results indicate that endophytic bacteria are supposed to be useful for biological control of environments contaminated with pesticides. © 2014 Elsevier Inc.


Haque M.A.,Gyeongsang National University | Barman D.N.,Gyeongsang National University | Kang T.H.,Gyeongsang National University | Kim M.K.,Gyeongsangnam do Agricultural Research and Extension Service | And 3 more authors.
Biosystems Engineering | Year: 2013

The aim of this work was to evaluate the effect of dilute sodium hydroxide for conversion of Miscanthus sinensis to fermentable sugars at boiling temperature with low residence time. Various concentrations of NaOH (0.75%-2.5%) were applied for treatment of Miscanthus in an autoclave at 105 °C for 10 min. The non-cellulosic surface granules composed of lignin, waxes, and partly of hemicelluloses were exhibited in pretreated Miscanthus. The scanning electron microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy studies showed that the 2.5% NaOH-treated Miscanthus exposed cellulose fibres and surface granules were removed, probably due to comprehensive disruption of the linkages between lignin and carbohydrates. The cellulose crystalline index was increased from the water-treatment to 2.0% NaOH-treatments and remarkably lowered by the 2.5% NaOH-treatment. Chemical component analysis showed that the level of cellulose increased to 70% and lignin was reduced to 4.2% by 2.5% NaOH-treated sample. The greatest removal of lignin and hemicellulose from pre-hydrolysate liquors was 74% and 55%, respectively. The reducing sugar yield with cellulase 15 FPU, β-glucosidase 30 IU, and xylanase 6 FXU g-1 substrate was estimated as 73% and 87% for 2.0% and 2.5% NaOH-treated samples respectively. The 2.5% NaOH-treatment is judged to be effective for disrupting Miscanthus recalcitrance in this pretreatment regime. © 2013 IAgrE.


Kim M.K.,Gyeongsangnam do Agricultural Research and Extension Service | Kang T.H.,Gyeongsang National University | Kim J.,Sunchon National University | Kim H.,Sunchon National University | Yun H.D.,Gyeongsang National University
Journal of Microbiology and Biotechnology | Year: 2012

The gene encoding an esterase enzyme was cloned from a metagenomic library of cow rumen bacteria. The esterase gene (est5S) was 1,026 bp in length, encoding a protein of 366 amino acid residues with a calculated molecular mass of 40,168 Da. The molecular mass of the enzyme was estimated to be 40,000 Da. The Est5S protein contains the Gly-X-Ser-X-Gly motif found in most bacterial and eukaryotic serine hydrolases. However, the Asp or Glu necessary for the catalytic triad [Ser-Asp-(Glu)-His] was not present, indicating Est5S represents a novel member of the GHSQG family of esterolytic enzymes. BlastP in the NCBI database analysis of Est5S revealed homology to hypothetical proteins and it had no homology to previous known lipases and esterases. Est5S was optimally active at pH 7.0 and 40°C. Among the p-nitrophenyl acylesters tested, high enzymatic activities were observed on the short-chain p-nitrophenyl acylesters, such as p-nitrophenyl acetate, etc. The conserved serine residue (Ser190) was shown to be important for Est5S activity. The primers that amplified the est5S gene did not show any relative band with 49 species of culturable rumen bacteria. This implies that a new group esterase gene, est5S, may have come from a noncultured cow rumen bacterium.


Barman D.N.,Gyeongsang National University | Haque Md.A.,Gyeongsang National University | Kang T.H.,Gyeongsang National University | Kim G.H.,Gyeongsang National University | And 3 more authors.
Environmental Technology (United Kingdom) | Year: 2014

The effect of dilute sodium hydroxide (NaOH) on reed straw structural change at 105°C temperature was evaluated in this study. Various concentrations of NaOH (1% to 2.5%) were used for pretreatment of reed straw at 105°C for 10 min. Scanning electron microscopy, atomic force microscopy and Fourier transform infrared spectroscopy studies showed that 2% and 2.5% NaOH pretreated sample exposed more cellulose fibers compared with other treatments. The cellulose crystalline index was increased by the 1% to 2.0% NaOH treatments and slightly lowered by the 2.5% NaOH treatment due to destructing cellulose fibres. Two per cent NaOH pretreatment caused 69.9% lignin removal, whereas 2.5% NaOH pretreatment removed 72.4% lignin. Besides, reed straw, when pretreated at 2% and 2.5% NaOH, resulted 56.4% and 60.5% hemicellulose removal, respectively. However, the difference in removal of lignin and hemicellulose between 2% and 2.5% NaOH treated reed straw was very marginal. In addition, very negligible increase of cellulose level was estimated, amounting 78.8% and 76.6% in 2.5% and 2% NaOH-treated sample, respectively. Moreover, after 72 h, reducing sugar yield was 81.2% and 83.3% using enzyme loading of 15 FPU (g dry biomass)-1 and 30 IU (g dry biomass)-1 and xylanase 4 FXU (g dry biomass)-1 from 2% and 2.5% NaOH pretreated reed straw, respectively. Reducing sugar yield was increased very marginally when NaOH concentration increased from 2% to 2.5% for reed straw pretreatment. Therefore, 2% NaOH is supposed to be effective for reed straw pretreatment at this mentioned condition. © 2013 Taylor & Francis.


PubMed | Gyeongsangnam do Agricultural Research and Extension Service
Type: Journal Article | Journal: Applied biochemistry and biotechnology | Year: 2012

This study was conducted to assess the gene duplication and diversification of tandem cellulase genes in thermophilic bacteria. The tandem cellulase genes cel5C and cel5D were cloned from Thermotoga maritima MSB8, and a survey of the thermophilic bacterial genome for tandem cel genes from the databases was carried out. A clone having 2.3 kb fragment from T. maritima MSB8 showed cellulase activity, which had two open reading frames in tandem (cel5C and cel5D). The cel5C gene has 954 bp, which encodes a protein of 317 amino acid residues with a signal peptide of 23 amino acids, and the other gene cel5D consisting of 990 bp encoding a protein of 329 amino acid residues. These two proteins have similarity with the enzymes of glycosyl hydrolase family 5. From the enzyme assay, it was observed that Cel5C was extracellular and Cel5D was intracellular cellulase. Phylogenetic and homology matrix analyses of DNA and protein sequences revealed that family 12 cellulase enzymes Cel12A and Cel12B displayed higher homology (>50 %), but Cel5C and Cel5D enzymes belong to family 5 displayed lower homology (<30 %). In addition, repeated and mirror sequences in tandem genes are supposed to show the existence of gene duplication and recombination.


PubMed | Gyeongsangnam do Agricultural Research and Extension Service
Type: Journal Article | Journal: Journal of microbiology and biotechnology | Year: 2012

The gene encoding an esterase enzyme was cloned from a metagenomic library of cow rumen bacteria. The esterase gene (est5S) was 1,026 bp in length, encoding a protein of 366 amino acid residues with a calculated molecular mass of 40,168 Da. The molecular mass of the enzyme was estimated to be 40,000 Da. The Est5S protein contains the Gly-X-Ser-X-Gly motif found in most bacterial and eukaryotic serine hydrolases. However, the Asp or Glu necessary for the catalytic triad [Ser-Asp-(Glu)-His] was not present, indicating Est5S represents a novel member of the GHSQG family of esterolytic enzymes. BlastP in the NCBI database analysis of Est5S revealed homology to hypothetical proteins and it had no homology to previous known lipases and esterases. Est5S was optimally active at pH 7.0 and 40 degrees C. Among the p-nitrophenyl acylesters tested, high enzymatic activities were observed on the short-chain p-nitrophenyl acylesters, such as p-nitrophenyl acetate, etc. The conserved serine residue (Ser190) was shown to be important for Est5S activity. The primers that amplified the est5S gene did not show any relative band with 49 species of culturable rumen bacteria. This implies that a new group esterase gene, est5S, may have come from a noncultured cow rumen bacterium.

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