Project description:Investigation of the kinetics of whole genome gene expression level changes in Bacillus subtilis NDmed strain during formation of submerged biofilm and pellicle. The Bacillus subtilis NDmed strain analyzed in this study is able to form thick and highly structured submerged biofilms as described in Bridier et al., (2011) The Spatial Architecture of Bacillus subtilis Biofilms Deciphered Using a Surface-Associated Model and In Situ Imaging. PLoS ONE 6(1):e16177.
Project description:Biofilms are structured communities of tightly associated cells that constitute the predominant state of bacterial growth in natural and human-made environments. Although the core genetic circuitry that controls biofilm formation in model bacteria such as Bacillus subtilis has been well characterized, little is known about the role that metabolism plays in this complex developmental process. Here, we performed a time-resolved analysis of the metabolic changes associated with pellicle biofilm formation and development in B. subtilis by combining metabolomic, transcriptomic, and proteomic analyses. We report a surprisingly widespread and dynamic remodeling of metabolism affecting central carbon metabolism, primary biosynthetic pathways, fermentation pathways, and secondary metabolism. Most of these metabolic alterations were hitherto unrecognized as biofilm-associated. For example, we observed increased activity of the tricarboxylic acid (TCA) cycle during early biofilm growth, a shift from fatty acid biosynthesis to fatty acid degradation, reorganization of iron metabolism and transport, and a switch from acetate to acetoin fermentation. Close agreement between metabolomic, transcriptomic, and proteomic measurements indicated that remodeling of metabolism during biofilm development was largely controlled at the transcriptional level. Our results also provide insights into the transcription factors and regulatory networks involved in this complex metabolic remodeling. Following these results, we demonstrate that acetoin production via acetolactate synthase is essential for robust biofilm growth and has the dual role of conserving redox balance and maintaining extracellular pH. This study represents a comprehensive systems-level investigation of the metabolic remodeling occurring during B. subtilis biofilm development that will serve as a useful roadmap for future studies on biofilm physiology.
Project description:The objective of the study was to uncover the developmental dynamics in Bacillus subtilis biofilms on a transcriptome level. The experiment covered a developmental timeline over two months of biofilm growth.
Project description:Identification of the specific WalR (YycF) binding regions on the B. subtilis chromosome during exponential and phosphate starvation growth phases. The data serves to extend the WalRK regulon in Bacillus subtilis and its role in cell wall metabolism, as well as implying a role in several other cellular processes.
Project description:Transcriptome comparison of Bacillus subtilis 168 grown on solid agar (sample 1-3) or aerated liquid (sample 4-7) 2xSG medium with and without of 0.1 mM manganese.
Project description:The natural biotope of Bacillus subtilis is the upper layer of soil where it grows as a biofilm. To mimic this physiological development and study the impact of nanoparticles during the formation of a biofilm in a contaminated soil, we have studied the proteomic response of the ancestral strain Bacillus subtilis 3610, which is able to form biofilm contrary to the 168 laboratory strain. The bacteria were grown on soft agar plates containing n-ZnO, n-TiO2 or ZnSO4 metal ion.