β-galactosidase GALA from with high transgalactosylation activity.

β-galactosidase catalyzes lactose hydrolysis and transfers reactions to produce prebiotics such as galacto-oligosaccharides (GOS) with potential applications in the food industry and pharmaceuticals. However, there is still a need for improved transgalactosylation activity of β-galactosidases and reaction conditions of GOS production in order to maximize GOS output and reduce production costs. In this study, a β-galactosidase gene, , from was expressed in , which not only hydrolyzed lactose but also had strong transgalactosylation activity to produce GOS.

Site-directed mutation of β-galactosidase from to reduce galactose inhibition in lactose hydrolysis.

β-Galactosidase is widely used for hydrolysis of whey lactose. However, galactose inhibition has acted as a major constraint on the catalytic process. Thus, it is sensible to improve upon this defect in β-galactosidase through protein modification.

The use of -mediated insertional mutagenesis sequencing to identify novel genes of involved in cellulase production.

A transfer DNA (T-DNA)-tagged mutant library of was screened for mutants with altered cellulase production using the plate-clearing zone assay. Three selected mutants (5-A7, 5-C6, and 13-B7) exhibited significantly depressed FPase, CMCase and xylanase activities compared with the wild-type strain upon shake-flask fermentation, while the pNPCase and pNPGase activities of the three mutants were relatively higher than those of the parental strain. Combined with the results of SDS-PAGE and mass spectrometry, we suggest that expression of the CMCases Cel6B, Cel7B, CMC3, and XynA/B/C was reduced in the mutant strains.

Enhanced Thermostability of Glucose Oxidase through Computer-Aided Molecular Design.

Glucose oxidase (GOD, EC.1.1.