Topic
Xylanase
About: Xylanase is a research topic. Over the lifetime, 7099 publications have been published within this topic receiving 163793 citations.
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TL;DR: A Bacillus sp.
60 citations
01 Jul 2009
TL;DR: Xylanase isolated from an estuarine environment may be useful in pulp pre-bleaching process to remove the hemicelluloses and could greatly reduce the need for pH and temperature readjustment, thus offering enormous technical and economic advantages.
Abstract: The aim of the present study was to isolate a thermostable and alkaline tolerant xylanase producing strain from an estuarine environment, and to produce, purify and characterize the enzyme. The bacterium, Bacillus subtilis isolated from the estuarine environment was grown in shake flasks to derive the optimum culture conditions and also cultured in lab scale fermentor to obtain more xylanase. Maximum enzyme production (128 U/mL) was recorded in stationary phase (36 h) of the culture. The enzyme was purified using ammonium sulphate precipitation (60% saturation), followed by DEAE-cellulose column chromatography. The enzyme was optimally active at 55 o C and pH 9.0. Influence of metal ions on enzyme activity revealed that, Fe 2+ , Ca 2+ , and Mg 2+ greatly enhanced the enzyme activity to 238, 148, 208 U/mL, respectively; whereas Hg 2+ (0 U/mL) and EDTA (18 U/mL) strongly inhibited the enzyme activity. Based on the results obtained, xylanase isolated in this study may be useful in pulp pre-bleaching process to remove the hemicelluloses. The use of thermostable alkaline tolerant xylanase for enzyme assisted pulp bleaching could greatly reduce the need for pH and temperature readjustment, thus offering enormous technical and economic advantages.
60 citations
TL;DR: A series of lipid-accumulating yeasts were examined for their potential to saccharify xylan and accumulate triglyceride as mentioned in this paper, including Candida, Cryptococcus, Lipomyces, Rhodosporidium, Rhodotorula, and Trichosporon.
Abstract: A series of lipid-accumulating yeasts was examined for their potential to saccharify xylan and accumulate triglyceride. Of the genera tested, including Candida, Cryptococcus, Lipomyces, Rhodosporidium, Rhodotorula, and Trichosporon, only Cryptococcus and Trichosporon isolates saccharified xylan. All of the strains could assimilate xylose and accumuate triglyceride under nitrogen-limiting conditions. Strains of Cryptococcus albidus were found to be especially useful for a one-step saccharification of xylan coupled to triglyceride synthesis. Cryptococcus terricolus, a strain constitutive for lipid accumulation, lacked extracellular xylanase, but did assimilate xylose and xylobiose and was able to continuously convert xylan to triglyceride if the culture medium was supplemented with xylanase.
60 citations
TL;DR: The constitutive homologous overexpression of one of the key process enzymes, namely an endo-xylanase 2 gene was incorporated into the F. oxysporum genome under the regulation of the gpdA promoter of Aspergillus nidulans, suggesting the potential regulation in a post transcriptional or translational level.
60 citations
TL;DR: To facilitate the future characterization of the protein via X-ray analysis and protein engineering, it was necessary to overexpress the enzyme in Escherichia coli and its expression was optimized.
60 citations