Project description:We used transcriptome analysis to evaluate the responses of one strain of Acidobacteria group 1, Granulicella sp WH15, to high quantities of carbon (3%) in culture medium.
Project description:Acidobacteria is a widely distributed phylum in soils, which possesses a relatively small number of cultured representatives. In general, Acidobacteria are considered to be oligothroph, able to succeed growth in poor nutrient environments and exhibiting slow growth under laboratory conditions. However, some isolates are able to grow in higher sugar concentrations, and several genes encoding glycosyl hydrolases were already found in acidobacterial genomes. The objective of this study was to sequence the genome of one acidobacterium species strain, i.e. Granulicella sp. (WH15), and determine the transcriptome and proteome responses in conditions with low and high sugar concentrations. Our study demonstrated the presence of 217 carbohydrate associated enzymes in the genome of the strain WH15. Integrated analysis of the transcriptomic and proteomic profiles showed that, in higher sugar concentrations, a stress response was triggered. Cell wall stress-related transcripts, such as sigma factor σW and the toxin-antitoxin (TA) systems were upregulated, as well as several proteins involved in detoxification and repair, for instance MdtA and OprM. KEGG metabolic pathway analysis indicated the repression of the carbon metabolism, especially the pentose phosphate pathway, demonstrating a decline of cell activity, with reduction of protein synthesis, carbohydrates metabolism and cell division. The present study demonstrated that the addition of a high sugar concentration in the culture medium triggered a stress response in Granulicella sp WH15, intensifying excretory functions to eliminate toxic compounds and reallocating resources towards maintenance instead of growth.
