Speaker
Description
Microbial proteome allocation has been introduced as a useful concept to rationalize metabolic switching and ribosome biology in fast microorganisms such as E. coli. When utilizing aerobically glucose at higher growth rates, E. coli initiates an overflow metabolism resulting in inefficient glucose utilization to accommodate the increased demand for ribosomes in the cellular proteome. Our work in CO2-reducing methanogens and acetogens, however, reveals a fundamentally different picture: Proteomic resource allocation plays only a minor role when growth rates change two orders of magnitude. In contrast, posttranslational regulation of metabolism is turning out to be a key aspect of microbial acclimation to different growth rates. Ribosomes operate over a much larger ranges of translation rates than in E. coli, and at low growth rates are limited by rRNA and not ribosomal protein. A refined model for proteome allocation is presented for chemolithoautotrophs.
