Project description:OBJECTIVE:To isolate and identify new methanogens from the rumen of Holstein steers in Korea. METHODS:Representative rumen contents were obtained from three ruminally cannulated Holstein steers (793±8 kg). Pre-reduced media were used for the growth and isolation of methanogens. Optimum growth temperature, pH, and sodium chloride (NaCl) concentration as well as substrate utilization and antibiotic tolerance were investigated to determine the physiological characteristics of the isolated strain. Furthermore, the isolate was microscopically studied for its morphology. Polymerase chain reaction of 16S rRNA and mcrA gene-based amplicons was used for identification. RESULTS:One strain designated as KOR-2 was isolated and found to be a non-motile irregular coccus with a diameter of 0.2 to 0.5 ?m. KOR-2 utilized H2+CO2 and formate but was unable to metabolize acetate, methanol, trimethylamine, 2-propanol, and isobutanol for growth and methane production. The optimum temperature and pH for the growth of KOR-2 were 38°C and 6.8 to 7.0, respectively, while the optimum NaCl concentration essential for KOR-2 growth was 1.0% (w/v). KOR-2 tolerated ampicillin, penicillin G, kanamycin, spectromycin, and tetracycline. In contrast, the cell growth was inhibited by chloramphenicol. Phylogenetic analysis of 16S rRNA and mcrA genes revealed the relatedness between KOR-2 and Methanoculleus bourgensis. CONCLUSION:Based on the physiological and phylogenetic characteristics, KOR-2 was thought to be a new strain within the genus Methanoculleus and named Methanoculleus bourgensis KOR-2.
Project description:Methanoculleus bourgensis, of the order Methanomicrobiales, is a dominant methanogenic archaeon in many biogas-producing reactor systems fed with renewable primary products. It is capable of synthesizing methane via the hydrogenotrophic pathway utilizing hydrogen and carbon dioxide or formate as the substrates. Here we report the complete and finished genome sequence of M. bourgensis strain MS2(T), isolated from a sewage sludge digester.
Project description:Methanoculleus bourgensis strain MAB1 has been identified as the hydrogenotrophic partner of mesophilic acetate-oxidising bacteria, a syntrophic relationship operating close to the thermodynamic equilibrium and of considerable importance in ammonia-rich engineered biogas processes. Methanoculleus bourgensis strain MAB1 belongs to the order Methanomicrobiales, family Methanomicrobiaceae, within the phylum Euryarchaeota. The genome shows a total size of 2,859,299 bp encoding 3450 predicted protein-encoding genes, of which only 1472 (43 %) have been assigned tentative functions. The genome encodes further 44 tRNA genes and three rRNA genes (5S, 16S and 23S rRNA). This study presents assembling and annotation features as well as genomic traits related to ammonia tolerance and methanogenesis.
