Comparison of the stability of CYP105A1 and its variants engineered for production of active forms of vitamin D.

CYP105A1 from Streptomyces griseolus converts vitamin D3 to its biologically active form, 1α,25-dihydroxy vitamin D3. R73A/R84A mutation enhanced the 1α- and 25-hydroxylation activity for vitamin D3, while M239A mutation generated the 1α-hydroxylation activity for vitamin D2. In this study, the stability of six CYP105A1 enzymes, including 5 variants (R73A/R84A, M239A, R73A/R84A/M239A (=TriA), TriA/E90A, and TriA/E90D), was examined.

Comparative studies on the activities of collagenases from Grimontia hollisae and Clostridium hystoliticum in the hydrolysis of synthetic substrates.

The collagenase produced by a gram-negative bacterium Grimontia hollisae strain 1706B (Ghcol) degrades collagen more efficiently than that produced by a gram-positive bacterium Clostridium histolyticum (Chcol), which is currently the most widely used collagenase in industry [Teramura et al. (Cloning of a novel collagenase gene from the gram-negative bacterium Grimotia (Vibrio) hollisae 1706B and its efficient expression in Brevibacillus choshinensis. J Bacteriol 2011;193:3049-3056)].

Cultivation of denitrifying anaerobic methane-oxidizing microorganisms in a continuous-flow sponge bioreactor.

Anaerobic treatment of sewage has many advantages; however, the effluent contains high levels of dissolved methane. In this study, we investigated the use of a closed-type downflow hanging sponge (DHS) reactor for application of the denitrifying anaerobic methane oxidation (DAMO) reaction for nitrogen and dissolved methane removal. When using nitrate, the DAMO reaction achieved a denitrification rate of 84.