Numerous microbes inhabit the mammalian intestinal track and strongly impact host physiology; however, our understanding of this ecosystem remains limited owing to the high complexity of the microbial community and the presence of numerous non-culturable microbes. Segmented filamentous bacteria (SFBs), which are clostridia-related Gram-positive bacteria,… (More)
In response to phosphate limitation, bacteria employ the Pho regulon, a specific regulatory network for phosphate acquisition. The two-component signal transduction system of PhoRB plays a crucial role in the induction of Pho regulon genes, leading to the adaptation to phosphate starvation. Herein, we identified the PhoRB system in Bacteroides fragilis, a… (More)
Six duocarmycins have been discovered during our search for new antitumor antibiotics and they showed extremely potent cytotoxic activity with IC50 values of 10(-12) M-10(-9) M on HeLa S3 cell. Three different producing strains isolated from soils were taxonomically assigned as Streptomyces. Duocarmycin A was unstable in culture broth, so improved culture… (More)
The structure of a new antibiotic, CV-1 was determined to be 1,2-diamino-1,2-N,N'-carbonyl-1,2-dideoxy-alpha-D-glucose hydrate by spectral and chemical studies. CV-1 possessed a unique open ring hemiaminal structure. CV-1 synthesized from N-carbamoyl-D-glucosamine was identical to material isolated from fermentation.