Project description:Members of the predatory Myxococcales (myxobacteria) possess large genomes, undergo multicellular development, and produce diverse secondary metabolites, which are being actively prospected for novel drug discovery. To direct such efforts, it is important to understand the relationships between myxobacterial ecology, evolution, taxonomy, and genomic variation. This study investigated the genomes and pan-genomes of organisms within the Myxococcaceae, including the genera Myxococcus and Corallococcus, the most abundant myxobacteria isolated from soils. Previously, ten species of Corallococcus were known, whereas six species of Myxococcus phylogenetically surrounded a third genus (Pyxidicoccus) composed of a single species. Here, we describe draft genome sequences of five novel species within the Myxococcaceae (Myxococcus eversor, Myxococcus llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogochensis, Myxococcus vastator, Pyxidicoccus caerfyrddinensis, and Pyxidicoccus trucidator) and for the Pyxidicoccus type species strain, Pyxidicoccus fallax DSM 14698T. Genomic and physiological comparisons demonstrated clear differences between the five novel species and every other Myxococcus or Pyxidicoccus spp. type strain. Subsequent analyses of type strain genomes showed that both the Corallococcus pan-genome and the combined Myxococcus and Pyxidicoccus (Myxococcus/Pyxidicoccus) pan-genome are large and open, but with clear differences. Genomes of Corallococcus spp. are generally smaller than those of Myxococcus/Pyxidicoccus spp. but have core genomes three times larger. Myxococcus/Pyxidicoccus spp. genomes are more variable in size, with larger and more unique sets of accessory genes than those of Corallococcus species. In both genera, biosynthetic gene clusters are relatively enriched in the shell pan-genomes, implying they grant a greater evolutionary benefit than other shell genes, presumably by conferring selective advantages during predation.
Project description:Leuconostoc fallax is known to be present during the manufacturing process of kimchi, the best-known traditional Korean dish. Here, we present the draft genome sequence of the type strain Leuconostoc fallax KCTC 3537 (1,638,971 bp, with a G+C content of 37.5%), which consists of 30 large contigs (>100 bp in size).
Project description:Sphagnum mosses dominate peatlands by employing harsh ecosystem tactics to prevent vascular plant growth and microbial degradation of these large carbon stores. Knowledge about Sphagnum-produced metabolites, their structure and their function, is important to better understand the mechanisms, underlying this carbon sequestration phenomenon in the face of climate variability. It is currently unclear which compounds are responsible for inhibition of organic matter decomposition and the mechanisms by which this inhibition occurs. Metabolite profiling of Sphagnum fallax was performed using two types of mass spectrometry (MS) systems and 1H nuclear magnetic resonance spectroscopy (1H NMR). Lipidome profiling was performed using LC-MS/MS. A total of 655 metabolites, including one hundred fifty-two lipids, were detected by NMR and LC-MS/MS-329 of which were novel metabolites (31 unknown lipids). Sphagum fallax metabolite profile was composed mainly of acid-like and flavonoid glycoside compounds, that could be acting as potent antimicrobial compounds, allowing Sphagnum to control its environment. Sphagnum fallax metabolite composition comparison against previously known antimicrobial plant metabolites confirmed this trend, with seventeen antimicrobial compounds discovered to be present in Sphagnum fallax, the majority of which were acids and glycosides. Biological activity of these compounds needs to be further tested to confirm antimicrobial qualities. Three fungal metabolites were identified providing insights into fungal colonization that may benefit Sphagnum. Characterizing the metabolite profile of Sphagnum fallax provided a baseline to understand the mechanisms in which Sphagnum fallax acts on its environment, its relation to carbon sequestration in peatlands, and provide key biomarkers to predict peatland C store changes (sequestration, emissions) as climate shifts.
Project description:Lactic acid bacterial strains were isolated from brines sampled after 7 days of an industrial sauerkraut fermentation, and six strains were selected on the basis of susceptibility to bacteriophages. Bacterial growth in cabbage juice was monitored, and the fermentation end products were identified, quantified, and compared to those of Leuconostoc mesenteroides. Identification by biochemical fingerprinting, endonuclease digestion of the 16S-23S intergenic transcribed spacer region, and sequencing of variable regions V1 and V2 of the 16S rRNA gene indicated that the six selected sauerkraut isolates were Leuconostoc fallax strains. Random amplification of polymorphic DNA fingerprints indicated that the strains were distinct from one another. The growth and fermentation patterns of the L. fallax isolates were highly similar to those of L. mesenteroides. The final pH of cabbage juice fermentation was 3.6, and the main fermentation end products were lactic acid, acetic acid, and mannitol for both species. However, none of the L. fallax strains exhibited the malolactic reaction, which is characteristic of most L. mesenteroides strains. These results indicated that in addition to L. mesenteroides, a variety of L. fallax strains may be present in the heterofermentative stage of sauerkraut fermentation. The microbial ecology of sauerkraut fermentation appears to be more complex than previously indicated, and the prevalence and roles of L. fallax require further investigation.