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.
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:Members of Acidobacteria phylum are difficult to isolate and grow. Nevertheless, for some isolated strains, trace elements solution is needed in culture media for Acidobacteria growth but the impact of these metals on their growth and metabolism is not known. Here we evaluated the effect of trace element solution SL-10 in on the growth of two strains (5B5 and WH15) of Acidobacteria belonging to Granulicella sp. and studied the proteomic responses to the metal with the best growth results, complementing with genomic characterization. Granulicella species had highest growth with the addition of Mn, as well as higher tolerance to this metal compared to seven other metal ions. Variations in tolerance to metal ion concentrations suggests that Granulicella sp. strains possess different mechanisms to deal with metal ion homeostasis and stress. The proteomic profiles of both strains indicated that Mn was more important in enhance enzymatic activity than to protein expression regulation. We did not find the most common transcriptional regulation of Mn homeostasis and we found candidate transporters that could be potentially involved in Mn homeostasis for Granulicella species. The presence of such transporters might be involved in tolerance to higher Mn concentrations, improving the adaptability of bacteria to metal enriched environments, such as the decaying wood-rich Mn environment where these two strains were isolated. Furthermore, strain 5B5 is likely more adapted to survive in an environment with higher concentration of several metal ions when compared to strain WH15.
Project description:Clavibacter michiganensis subsp. michiganensis is an important Gram-positive phytopathogenic bacteria that causes bacterial wilt and canker in tomato. The genome of the type strain, NCPPB382, has been sequenced and annotated, however comparative genomics suggests that certain regions are under- or misannotated. In order to improve the genome annotation, we have undertaken a proteogenomic study of this important pathogen. Samples were grown in culture and the proteome of the pellet and supernatant were analyzed separately using shotgun HPLC-MS/MS. These proteomics datasets were analyzed and a number of missing gene were found and a number of existing gene calls were modified.
