Transcriptomic and proteomic changes associated with cobalamin-dependent propionate production by the rumen bacterium .

Unlabelled: is an abundant rumen bacterium that produces propionate in a cobalamin (vitamin B)-dependent manner via the succinate pathway. However, the extent to which this occurs across ruminal and closely related bacteria, and the effect of cobalamin supplementation on the expression of propionate pathway genes and enzymes has yet to be investigated. To assess this, we screened 14 strains and found that almost all strains produced propionate when supplemented with cobalamin.

Rumen isolate NK3A20 exhibits metabolic flexibility in response to substrate and coculture with a methanogen.

Hydrogen (H) is the primary electron donor for methane formation in ruminants, but the H-producing organisms involved are largely uncharacterized. This work integrated studies of microbial physiology and genomics to characterize rumen bacterial isolate NK3A20 of the family . Isolate NK3A20 was the first recognized isolate of the NK3A20 group, which is among the ten most abundant bacterial genera in 16S rRNA gene surveys of rumen microbiota.

gen. nov. sp. nov. and sp. nov., two rumen bacterial species of a novel proposed family, fam. nov.

Two strains of Gram-negative, anaerobic, rod-shaped bacteria, from an abundant but uncharacterized rumen bacterial group of the order ', were phylogenetically and phenotypically characterized. These strains, designated R-7 and WTE2008, shared 98.6-99.

Steroidogenic acute regulatory protein transcript abundance in the eel, Anguilla australis: changes during the induced reproductive cycle and effects of follicle-stimulating hormone during previtellogenesis.

Steroidogenic acute regulatory protein (StAR) mRNA levels in the eel ovary were assayed by quantitative PCR and related to plasma steroid levels throughout oogenesis in order to shed light on the previously considered 'aberrant' prematurational increase in plasma levels of estradiol-17β (E2). Total ovarian StAR transcript abundance mirrored circulating levels of E2, but not of 11-ketotestosterone (11KT). The study was complemented by evaluation of in vitro effects of follicle-stimulating hormone (FSH) on ovarian StAR transcript abundance and on short-term ('acute') radiolabelled pregnenolone-supported steroid metabolism by ovarian fragments to understand how the production of steroids during previtellogenic oocyte growth is regulated.