Project description:This study uses iTRAQ based proteomics approach to understand the cellular metabolic machineries present within the Clostridium strain BOH3 (discovered by our group) which can simultaneously utilise both glucose (six carbon sugar) and xylose (five carbon sugar) to produce butanol and riboflavin.
Project description:One microbial organism always contains multiple DNA modification systems as defense strategies or epigenetic controls. Here, we describe crosstalk between two distinct DNA modifications with different target sequence motif: DNA phosphorothioation (PT, GPSAAC/GPSTTC by DndACDE proteins) and N6-methyl-adenine methylation (m6A, G6mATC by Dam protein). By using a newly developed DNA modification sequencing method PT nick-seq, we found that half of PT modifications change from GAAC/GTTC to GATC sites after bacteria have lost Dam.
Project description:Solventogenic Clostridium species ferment carbohydrates to acetone, butanol and ethanol which are well-known next-generation biofuels. However, repeated subculture of or continuous fermentation by Clostridium often decreases and eventually terminates the solvent production and spore formation, which is a process called strain degeneration. Supplementation of CaCO3 to fermentation medium could partially recover metabolism of degenerated strain by more than 50% increase of cell growth and solvent production. The transcriptome profile of Clostridium beijerinckii NCIMB 8052 (DG-8052) and its response to CaCO3 treatment were analysed by microarray. Since fermentation by C. beijerinckii NCIMB 8052 is a biphasic process, gene expressions of two fermentations were compared at each stage, i.e. 12h and 24h fermentation time representing acidogenic phase and solventogenic phase, respectively. This study examined expression of 5168 genes capturing 98.6% of the C. beijerinckii NCIMB 8052 genome. With the addition of CaCO3, DG-8052 had 565 and 916 genes significantly up-regulated at acidogenic phase and solventogenic phase, respectively. According to the enrichment analysis of pathway and Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, these genes were significantly overrepresented in cellular functions such as Amino acid transport and metabolism, organic acid biosynthetic process, bacteria chemotaxis and defense mechanisms. On the other hand, there were 704 and 1044 genes significantly down-regulated at acidogenic phase and solventogenic phase, respectively. These repressed genes were mainly enriched in functions such as ion transmembrane transport, ATP synthesis, oxidative phosphorylation.
Project description:The possibility of establishing a Clostridium-based biorefinery is an attractive and viable alternative, due to the wide metabolic versatility of these microorganisms. The Bioprocesses and Bioprospecting group of the Universidad Nacional de Colombia has obtained the genome of Clostridium sp. IBUN13A, which has shown the ability to produce solvents from various substrates and postulated the need to expand the knowledge of the physiology of the bacteria, so, this study establishes the differences in the transcriptomic profile of the strain when it is cultivated in glycerol respect to glucose after 24 hours of fermentation. For this, a RNA-seq study was carried out, and some of the genes that increased its expression on glycerol were related to the oxidative route of its consumption. The enrichment analysis of Gene Ontology terms showed that the biological phenomena with the highest representation within the differentially expressed genes correspond to oxidation-reduction processes. This first approach to the global transcriptomic study of glycerol fermentation allows the understanding of the metabolism of the microorganism with the purpose of choosing targets for genetic modification.