Project description:Whole-genome shotgun assembly and analysis of the genome of Streptomyces mobaraensis DSM 40847, a strain for industrial production of microbial transglutaminase
Project description:This study compared the genome of Streptomyces rimosus rimosus against that of Streptomyces coelicolor. It also compared 4 strains with changes in oxytetracycline production and derived from G7, the type strain, against G7. Keywords: Comparative genomic hybridization
Project description:We identified genome-wide binding regions of NdgR in Streptomyces coelicolor using chromatin immunoprecipitation sequencing (ChIP-seq). We constructed 6×myc-tagged NdgR strain using homologous recombination with myc-tagging vector. Analysis of the sequencing data aligned to Streptomyces coelicolor genome database (NC_003888).
Project description:Soil is a rich environment for microbes, where they compete for space and resources. Streptomyces bacteria are well-known for their ability to synthesize natural products, particularly antibiotics, that are used in chemical defense against competing microbes. Here we show that Streptomyces are, in fact, predatory bacteria. Upon encountering yeast cells, Streptomyces initiate the production of numerous enzymes that digest the cell wall and cell membrane. In addition, the interaction triggers the production of natural products that destabilize the yeast cell membrane. Collectively these actions lead to the death of yeast cells and release of cellular building blocks that Streptomyces can use as nutrients. The work fundamentally shifts the paradigm of how Streptomyces are perceived within the soil microbiome ecosystem.
Project description:Streptomyces mobaraensis transglutaminase (TGase) is extracellularly expressed as a zymogen and then activated by TGase-activating protease (TAP). In this study, we reported the strategy for improving TGase production via the regulation of TAP activity in S. mobaraensis. First, we analyzed the effects of three inorganic nitrogen sources on TGase production. With 30 mM nitrogen content, the time to the peak of TGase activity induced by (NH4)2SO4 or NH4Cl was 72 h, 12 h earlier than that of the fermentation without adding NH4 +. SDS-PAGE analysis indicated that NH4 + accelerated the TGase activation in S. mobaraensis. Then, we examined the effect of NH4 + on TAP biosynthesis using a TGase-deficient S. mobaraensis strain. It showed that NH4 + enhanced the TAP activity at the early stage of the fermentation, which was dependent on the concentration and time of NH4 + addition. Last, the yield and productivity of S. mobaraensis TGase were increased by 1.18-fold and 2.1-fold, respectively, when optimal NH4 + addition (60 mM and 12 h) was used. The fermentation period was shortened from 84 to 48 h. The NH4 + addition also increased the storage stability of crude enzyme at room temperature. These findings will benefit the TGase production and its activation mechanism in S. mobaraensis.