RESUMEN
Microbial community profiles of recently formed hot spring systems ranging in temperatures from 57°C to 100°C and pH values from 2 to 4 in Hveragerði (Iceland) were analyzed with PhyloChip G3 technology. In total, 1173 bacterial operational taxonomic units (OTUs) spanning 576 subfamilies and 38 archaeal OTUs covering 32 subfamilies were observed. As expected, the hyperthermophilic (â¼100°C) spring system exhibited both low microbial biomass and diversity when compared to thermophilic (â¼ 60°C) springs. Ordination analysis revealed distinct bacterial and archaeal diversity in geographically distinct hot springs. Slight variations in temperature (from 57°C to 64°C) within the interconnected pools led to a marked fluctuation in microbial abundance and diversity. Correlation and PERMANOVA tests provided evidence that temperature was the key environmental factor responsible for microbial community dynamics, while pH, H2S, and SO2 influenced the abundance of specific microbial groups. When archaeal community composition was analyzed, the majority of detected OTUs correlated negatively with temperature, and few correlated positively with pH.
Asunto(s)
Archaea/genética , Bacterias/genética , ADN de Archaea/genética , ADN Bacteriano/genética , Manantiales de Aguas Termales/microbiología , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Ribosómico 16S/genética , Acidobacteria/genética , Actinobacteria/genética , Alphaproteobacteria/genética , Betaproteobacteria/genética , Biodiversidad , Crenarchaeota/genética , Deltaproteobacteria/genética , Euryarchaeota/genética , Gammaproteobacteria/genética , Islandia , Filogenia , Proteobacteria/genética , Análisis de Secuencia de ADNRESUMEN
As part of an undergraduate microbiology course, a yellow-orange-pigmented, Gram-staining negative, rod-shaped, non-motile bacterial strain was isolated from a glass tank housing several red-spotted newts (Notophthalmus viridescens). The sequence of the 16S rRNA gene of this strain, designated KM(T), was 97.4-98.0â% similar to those of the type strains of Chryseobacterium luteum, C. shigense and C. vrystaatense, while the similarity levels for protein-coding genes were less than 94.7â% for rpoB, less than 92.1â% for groEL and less than 87.1â% for gyrB. These values are lower than for many other established distinct species. Polyphasic characterization and comparison to these relatives revealed that strain KM(T) was similar to other Chryseobacterium strains in that it contained MK-6 as its major respiratory quinone and phosphatidylethanolamine as the most abundant polar lipid, produced flexirubin-type pigments, oxidase and catalase and primarily contained the fatty acids iso-C15â:â0, iso-C17â:â1ω9c, iso-C17â:â0 3-OH and summed feature 3 (comprising C16â:â1ω6c and/or C16â:â1ω7c). Based on the results of this study, strain KM(T) represents a novel species, for which the name Chryseobacterium angstadtii sp. nov. is proposed. The type strain is KM(T) (â=âATCC BAA-2160(T)â=âNRRL B-59516(T)â=âKCTC 23297(T)).
