Bioconversion of vitamin D3 to calcifediol by using resting cells of Pseudonocardia sp.

Objectives: Resting cells of Pseudonocardia sp. KCTC 1029BP were used for the bioconversion of vitamin D3 to calcifediol which is widely used to treat osteomalacia and is industrially produced by chemical synthesis.

Results: To obtain the maximum bioconversion yield of calcifediol by the microbial conversion of vitamin D3, a two-step optimization process was used, including the Plackett-Burman and the central composite designs.

Whole cell bioconversion of vitamin D3 to calcitriol using Pseudonocardia sp. KCTC 1029BP.

Calcitriol is an important drug used for treating osteoporosis, which can be produced from vitamin D3. The current method of producing calcitriol from vitamin D3 during cultivation of microbial cells results in low yields of calcitriol and high purification costs. Therefore, in this study, the steps of cell cultivation and bioconversion of vitamin D3 to calcitriol were separated.

Putative TetR family transcriptional regulator SCO1712 encodes an antibiotic downregulator in Streptomyces coelicolor.

A tetR family transcriptional regulatory gene (SCO1712) was identified as a global antibiotic regulatory gene from a Streptomyces interspecies DNA microarray analysis. SCO1712 disruption in Streptomyces coelicolor not only upregulated antibiotic biosynthesis through pathway-specific regulators when a previously identified pleiotropic downregulatory wblA was expressed but also further stimulated antibiotic production in a wblA deletion mutant, implying that SCO1712 might encode a novel antibiotic downregulator.

Optimization of medium components for high-molecular-weight hyaluronic acid production by Streptococcus sp. ID9102 via a statistical approach.

Hyaluronic acid (HA), linear high-molecular-weight glycosaminoglycan produced from Streptococcus sp., has raised interest in the medical and cosmetics industries because of the various biological functions of HA. In this paper, we report on the optimization of medium components for HA production in Streptococcus sp.

Comparative transcriptome analysis for avermectin overproduction via Streptomyces avermitilis microarray system.

Avermectin and its analogs are major commercial antiparasitic agents in the fields of animal health, agriculture, and human infections. To increase our understanding about the genetic mechanism underlying avermectin overproduction, comparative transcriptomes were analyzed between the low producer S. avermitilis ATCC31267 and the high producer S.