@article { ISI:000270147700049, title = {Biochemical characterization of two xylanases from yeast Pseudozyma hubeiensis producing only xylooligosaccharides}, journal = {Bioresource Technology}, volume = {100}, number = {24}, year = {2009}, month = {DEC}, pages = {6488-6495}, publisher = {ELSEVIER SCI LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

Two distinct xylanases from Pseudozyma hubeiensis NCIM 3574 were purified to homogeneity. The molecular masses of two native xylanases were 33.3 kDa (PhX33) and 20.1 kDa (PhX20). PhX33 is predominant with alpha-helix and PhX20 contained predominantly beta-sheets. Xylanase, PhX33, possesses three tryptophan and one carboxyl residues at the active site. The active site of PhX20 comprises one residue each of tryptophan, carboxyl and histidine. Carboxyl residue is mainly involved in catalysis and tryptophane residues are solely involved in substrate binding. Histidine residue present at the active site of PhX20 appeared to have a role in substrate binding. Both the xylanases produced only xylooligosaccharides (XOS) with degree of polymerization (DP) 3-7 without formation of xylose and xylobiose. These XOS could be used in functional foods or as prebiotics. Lc ms-ms ion search of cryptic digestion of these xylanases revealed that there is no significant homology of peptides with known fungal xylanase sequences which indicate that these xylanases appear to be new. (c) 2009 Elsevier Ltd. All rights reserved.

}, keywords = {Cellulase-free xylanase, Pseudozyma hubeiensis, Xylooligosaccharides}, issn = {0960-8524}, doi = {10.1016/j.biortech.2009.07.064}, author = {Adsul, Mukund G. and Bastawade, Kulbhushan B. and Gokhale, Digambar V.} } @article { ISI:000322464500002, title = {Biomass to biodegradable polymer (PLA)}, journal = {RSC Advances}, volume = {3}, number = {33}, year = {2013}, month = {JUN}, pages = {13558-13568}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Lignocellulosic biomass is renewable and cheap, and it has the potential to displace fossil fuels for the production of fuels and chemicals. Biomass derived lactic acid is an important compound that can be used as a chemical platform for the production of a variety of important chemicals on a large scale. The quality of the monomers of lactic acid and lactide, as well as the chemical changes induced during polymerization and processing, are crucial parameters for controlling the properties of the resulting polylactic acid (PLA) products. In this review, we outline the process of exploiting biomass for the production of polylactic acid, a biodegradable polymer which is well-known as a sustainable bioplastic material.

}, issn = {2046-2069}, doi = {10.1039/c3ra41592a}, author = {Singhvi, Mamata and Gokhale, Digambar V.} } @article { ISI:000346189100055, title = {Biocatalyst development for lactic acid production at acidic pH using inter-generic protoplast fusion}, journal = {RSC Advances}, volume = {5}, number = {3}, year = {2015}, month = {DEC}, pages = {2024-2031}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Global warming and environmental problems force us to develop sustainable processes based on the use of biocatalysts that are eco-friendly with the least potential toxicity. Lactic acid fermentation at neutral pH generates a large amount of gypsum during down-stream processing. Hence it is essential to develop Lactobacillus strains which produce lactic acid at acidic pH thus making the whole downstream process environmentally friendly. Fusant F3 was generated using protoplast fusion between Lactobacillus delbrueckii Mut Uc-3 and Acetobacter pasteurianus NCIM 2314 on solid media at pH 4.0. Fusant F3 was further treated by UV irradiation to generate a mutant, FM1, with improvements in acid tolerance which produced five-fold more lactic acid than the parent strain at acidic pH. The molecular studies using RAPD markers demonstrated that the fusant is derived from both the parental strains, Acetobacter and Lactobacillus and the mutant is derived from the fusant. The utilization of such acid tolerant strains could be able to produce free lactic acid at acidic pH without using neutralizing agents and will offer an effective means for designing environmentally benign processes for lactic acid production.

}, issn = {2046-2069}, doi = {10.1039/c4ra11104d}, author = {Singhvi, Mamata and Gurjar, Gayatri and Gupta, Vidya and Gokhale, Digambar V.} } @article { ISI:000355242800010, title = {Biomass exploitation - a challenge finding its way to reality}, journal = {Current Science}, volume = {108}, number = {9}, year = {2015}, month = {MAY}, pages = {1593-1594}, publisher = {INDIAN ACAD SCIENCES}, address = {C V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIA}, abstract = {

Lignocellulosic biomass holds the key to supplying the basic needs of society for sustainable production of chemicals and fuels without impacting the human food supply. The production of second-generation biofuels and chemicals from lignocellulosic biomass has not yet been commercialized due to its complex and recalcitrance structure. Therefore, the challenges involved in the production of lignocellulosic biomass-derived fuels and chemicals must be addressed. Search for economic pretreatment methods has been recognized as one of the main hurdles for processing of biomass to biofuels and chemicals. The conversion of all biomass components, lignin in particular, would greatly contribute to the economic viability of biomass-based processes for second-generation biofuels and chemicals. Hydrolysis of lignocellulose carbohydrates into fermentable sugars requires a suitable cellulase enzyme cocktail acting on both raw as well as pretreated biomass. Depending on raw material and pretreatment technology, the enzyme mixtures must be designed to degrade biomass carbohydrates. Recent publications on GVL-pretreatment to solubilize and degrade carbohydrates in biomass and CelA enzyme acting on raw biomass would probably meet the challenges in biomass conversion technologies.

}, issn = {0011-3891}, author = {Singhvi, Mamata S. and Gokhale, Digambar V.} }