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:Biofilms are structured communities of tightly associated cells that constitute thepredominant state of bacterial growth in naturaland human-madeenvironments. Although the core genetic circuitry that controls biofilm formation in model bacteria such as Bacillus subtilishas been well characterized, little is known about the role that metabolism plays in this complex developmental process. Here, weperformed a time-resolved analysisof the metabolic changes associated with pellicle biofilm formation and development inB. subtilisby 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 hithertounrecognized 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 generally controlled at the transcriptional level. Our resultsalsoprovide insights into the transcription factors and regulatory networks involved in thiscomplexmetabolic remodeling. Following upon these results, we demonstrate that acetoin production via acetolactate synthase is essential for robust biofilm growthand has the dual role of conservingredox balance and maintaining extracellularpH.This study represents a comprehensive systems-level investigation of the metabolic remodeling occurring during B. subtilisbiofilm development that will serve as a useful roadmap for future studies on biofilm physiology.
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: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:During early mammalian embryogenesis, dynamic changes in cell growth and proliferation are tightly linked to the underlying genetic and metabolic regulation. However, our understanding of metabolic reprogramming and its impact on epigenetic regulation in early embryo development remains elusive. We reconstruct their metabolic landscapes from the 2-cell and blastocyst stages, as well as their transition from totipotency to pluripotency. While 2-cell embryos favor methionine, polyamine and glutathione metabolism and stay in a more reductive state, blastocyst embryos have higher mitochondrial metabolites related to the tricarboxylic acid cycle, and present a more oxidative state. Moreover, we identify a reciprocal relationship between α-ketoglutarate (α-KG) and the competitive inhibitor of α-KG-dependent dioxygenases, L-2-hydroxyglutarate (2-HG), where 2-cell embryos inherited from oocytes and 1-cell zygotes display higher L-2-HG, whereas blastocysts show higher α-KG.Supplementing 2-HG or knocking down L2hgdh, a gene encoding the 2-HG consuming enzyme L-2-hydroxyglutarate dehydrogenase impeded erasure of global histone methylation markers . Together, our data demonstrate dynamic and interconnected metabolic, transcriptional and epigenetic network remodeling during murine early embryo development.
Project description:We applied time-course transcriptomics and genetics to identify sigma factors, metabolic processes and adhesins that drive biofilm formation. These analyses revealed that extracellular pyruvate induces biofilm formation in the presence of DOC. In the absence of DOC, pyruvate supplementation was sufficient to induce biofilm formation in a process that was dependent on pyruvate transport by the membrane protein CstA.