SCHEMA structure-guided recombination of 3 fungal class II cellobiohydrolases (CBH II cellulases) has yielded a collection of highly thermostable CBH II chimeras. Twenty-three of 48 genes sampled from the 6,561 possible chimeric sequences were secreted by the Saccharomyces cerevisiae heterologous host in catalytically active form. Five of these chimeras have half-lives of thermal inactivation a...

A new thermostable d-methionine amidase was found in a cell-free extract of Brevibacillus borstelensis BCS-1. After five steps of purification, the specific activity increased approximately 207-fold and the purity was more than 98%. The molecular weight of the enzyme was estimated to be 199 kDa by gel permeation chromatography and 30 kDa by sodium dodecyl sulfate–polyacrylamide gel electrophore...

We describe an efficient SCHEMA recombination-based approach for screening homologous enzymes to identify stabilizing amino acid sequence blocks. This approach has been used to generate active, thermostable cellobiohydrolase class I (CBH I) enzymes from the 390 625 possible chimeras that can be made by swapping eight blocks from five fungal homologs. Constructing and characterizing the parent e...

Superoxide dismutase (SOD) is a critical enzyme associated with controlling oxygen toxicity arising out of oxidative stress in any living system. A hyper-thermostable SOD isolated from a polyextremophile higher plant Potentilla atrosanguinea Lodd. var. argyrophylla (Wall. ex Lehm.) was engineered by mutation of a single amino acid that enhanced the thermostability of the enzyme to twofold. The ...

The thermostability of tyrosinase from three wild type strains of Neurospora crassa has been investigated. For this purpose a sequence comparison of two thermostable and one thermolabile tyrosinase isoenzyme was carried out. It revealed that at position 201 the thermostable enzyme forms share an aspartate residue in contrast to an asparagine residue in the thermolabile form. In addition, one of...

Thermostable lipase from Geobacillus thermodenitrificans IBRL-nra was purified and characterized. The production of thermostable lipase from Geobacillus thermodenitrificans IBRL-nra was carried out in a shake-flask system at 65°C in cultivation medium containing; glucose 1.0% (w/v); yeast extract 1.25% (w/v); NaCl 0.45% (w/v) olive oil 0.1% (v/v) with agitation of 200 rpm for 24 hours. The extr...

BACKGROUND Many researchers have reported on the optimization of protease production; nevertheless, only a few have reported on the optimization of the production of organic solvent-tolerant proteases. Ironically, none has reported on thermostable organic solvent-tolerant protease to date. The aim of this study was to isolate the thermostable organic solvent-tolerant protease and identify the c...

A major obstacle to using widely available and low-cost lignocellulosic feedstocks to produce renewable fuels and chemicals is the high cost and low efficiency of the enzyme mixtures used to hydrolyze cellulose to fermentable sugars. One possible solution entails engineering current cellulases to function efficiently at elevated temperatures in order to boost reaction rates and exploit several ...

The effect of the lipid environment on the thermostability of three respiratory terminal oxidases was determined. Cytochrome-c oxidase from beef heart and Bacillus stearothermophilus were used as representative proteins from mesophilic and thermophilic origin, respectively. Quinol oxidase from the archaeon Sulfolobus acidocaldarius represented the model for a extreme thermoacidophilic enzyme. A...