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The recombinant laccase from Thermus thermophilus was applied to the biobleaching of wheat straw pulp. The best bleaching effect was when the pulp was treated with 3 U laccase g−1 dry pulp at 90°C, pH 4.5, 8% consistency for 1.5 h. Under these conditions, the pulp brightness was increased by 3.3% ISO, and the pulp kappa number was decreased by 5.6 U.(More)
Ethanologenic Thermoanaerobacter species produce ethanol from lignocellulose derived substrates at temperatures above 70 degrees C. In the final steps of ethanol formation, two bifunctional acetaldehyde/alcohol dehydrogenases, AdhB and AdhE, and an alcohol dehydrogenase, AdhA, catalyze redox reactions between acetyl-CoA and ethanol via an acetaldehyde(More)
The gene of beta-glucuronidase from Thermotoga maritima was cloned into the plasmid pHsh, and expressed in Escherichia coli JM109. The recombinant protein was purified to homogeneity by a simple step, heat treatment. The recombinant enzyme had a molecular mass of 65.9 kD. The optimal activity of beta-glucuronidase was found at pH 5.0 and 80 degrees C. The(More)
OBJECTIVE To estimate the disease burden attributable to unsafe water and poor sanitation and hygiene in China, to identify high-burden groups and to inform improvement measures. METHODS The disease burden attributable to unsafe water and poor sanitation and hygiene in China was estimated for diseases resulting from exposure to biologically contaminated(More)
Anaerobes can obtain the entire cell's ATP by glycolysis and remove resulting reducing power by fermentation. There is a delicate balance in redox status to obtain a maximal growth of these cells, and the conditions to change redox fluxes can induce kinds of changes in metabolism. The fundamental knowledge on sensing redox status and coupling redox signals(More)
Bacillus subtilis produces acetoin as a major extracellular product. However, the by-products of 2,3-butanediol, lactic acid and ethanol were accompanied in the NADH-dependent pathways. In this work, metabolic engineering strategies were proposed to redistribute the carbon flux to acetoin by manipulation the NADH levels. We first knocked out the acetoin(More)
Bacillus subtilis mutants were obtained after the wild strain JNA 3-10 was mutagenized by UV irradiation coupled with diethyl sulfate. A visual filter assay was employed for the qualitative identification of 2,3-butanediol dehydrogenase (BDH) blocked B. subtilis. Selected mutants were tested for the activities of acetoin reductase (AR) and BDH. According to(More)
Recently, studies performed on Saccharomyces cerevisiae and Candida albicans have confirmed the importance of fungal glycosylphosphatidylinositol (GPI)-anchored aspartyl proteases (yapsins) for cell-wall integrity. Genome sequence annotation of Pichia pastoris also revealed seven putative GPI-anchored aspartyl protease genes. The five yapsin genes assigned(More)
Acetoin, a major extracellular catabolic product of Bacillus subtilis cultured on glucose, is widely used to add flavor to food and also serves as a precursor for chemical synthesis. The biosynthesis of acetoin from pyruvate requires the enzymes α-acetolactate synthase (ALS) and α-acetolactate decarboxylase (ALDC), both of which are encoded by the alsSD(More)
A beta-N-acetylglucosaminidase gene (nag84A) was cloned from Clostridium paraputrificum M-21 in Escherichia coli. The nag84A gene consists of an open reading frame of 4647 by encoding 1549 amino acids, with a deduced molecular weight of 174,311, which have a catalytic domain belonging to family 84 of the glycoside hydrolases. Nag84A was purified from a(More)