Project description:The samples in this series were used to analyze the transcriptome of the CtrA regulon using wild type (SB1003) and ctrA mutant (SBRM1) strains of Rhodobacter capsulatus. As well, the transcriptome of growth phase regulation in R. capsulatus SB1003 between log and stationary phases was determined.
Project description:Global transcriptome analyses at growth before and after 10 min of photooxidative stress were applied to monitor stress dependent gene expression in the alpha-proteobacterium Rhodobacter capsulatus. Transcriptome profiles of pigmented cultures with high aeration were monitored before and after the onset of singlet oxygen stress.
Project description:The diazotrophic bacterium Rhodobacter capsulatus synthesizes a molybdenum nitrogenase and an alternative iron-only nitrogenase, enabling growth with molecular dinitrogen as sole nitrogen source. Regulation of nitrogen fixation was analyzed by proteome profiling of wild-type and mutant strains lacking the transcriptional regulators NifA, AnfA, and MopAB.
Project description:The circular bioeconomy has become a crucial strategy for sustainable development, especially by upcycling organic-rich by-products from various industrial processes. Purple non-sulphur bacteria (PNSB) have emerged as excellent candidates in this field, demonstrating exceptional metabolic versatility. While the growth of PNSB on sugar-rich streams has been extensively explored, the sugar assimilation metabolism remains poorly understood. Here, we explore the metabolic mechanisms of sucrose utilisation in two phototrophic purple non-sulphur bacteria (PNSB), Rhodospirillum rubrum and Rhodobacter capsulatus. Our findings demonstrate distinct carbohydrate hydrolysis and assimilation capacities, as well as the use of different redox strategies for each species. Moreover, Rhodospirillum rubrum could only grow on sucrose when co-cultivated with Rhodobacter capsulatus. This trophic link between Rhodospirillum rubrum and Rhodobacter capsulatus in sucrose containing co-culture was characterised and resulted in significantly enhanced productivity compared to pure cultures. Finally, we demonstrate that the synergy observed between Rhodospirillum rubrum and Rhodobacter capsulatus can be successfully scaled up in a photobioreactor system. Our study highlights how fundamental knowledge of the metabolism, trophic link and general microbial ecology concept might be useful for the development of biobased resource recovery strategies.
