The phylogenetic diversity of Thermus and Meiothermus from microbial mats of an Australian subsurface aquifer runoff channel

Abstract

Spectral analysis of the cell free extracts of four mat samples colonizing a Great Artesian Bain (GAB) aquifer bore runoff channel suggested that Thermus was present in the 75 degrees C grey mat, Meiothermus was present in the 66 degrees C red mat, a mixed population of Meiothermus/Thermus and photosynthetic microbes were present in the 57 degrees C green mat and photosynthetic microbes were present in the 52 degrees C brown mat. Enumeration studies indicated that Thermus dominated the grey mats and Meiothermus dominated the red mat but both were absent in samples collected at the bore source (89 degrees C) and below the bore source (88 degrees C). Culture-dependent studies followed by 16S rRNA gene sequence analysis indicated that 13 of the 14 Thermus isolates clustered closely with each other and to T. igniterrae, with the remaining strain clustering with Thermus strain SRI-96. The two Meiothermus isolates were closely related to Meiothermus ruber. A culture-independent study with 367 16S rRNA gene clones concurred that Thermus dominated the grey mat, but to a lesser extent in the red mat and the green mats and its complete absence in the brown mat. Of the four Thermus phylogroups identified one phylogroup dominated the cloned library and was related to the cluster represented by T. scotoductus. The second most dominant phylogroup was related to the cluster represented by T. igniterrae and the third and fourth phylogroups, which were the least dominant, were related to cluster represented by Thermus strain SRI-248 and T. oshima respectively. Meiothermus was only represented in the 16S rRNA gene libraries of the red, green and brown mats and formed two phylogroups, of which the most dominant was associated with the red mat and phylogenetically related to M. ruber while the second phylogroup was found only in the green mat gene library and was related to M. cerberus.

Microbial Community Comparisons as a Function of the Physical and Geochemical Conditions of Galápagos Island Fumaroles

“…The temperature recorded at site CH1 was 56 • C, within the range of temperatures for optimal growth of Meiothermus, and several strains of M. silvanus have been isolated from hot spring environments including a hot spring in Vizela, Portugal, and from Geysir geothermal area in Iceland (Chung et al 1997). A pH of 6.0 was recorded at the sample site, which is reasonable for growth of Meiothermus as many isolates are neutrophilic (Chung et al 1997;Spanevello and Patel, 2004). Previous studies showed that some strains of M. silvanus required reduced sulfur compounds for growth (Chung et al, 1997), suggesting that at site CH1, sulfur-rich precipitates derived from fumarole gases may be important for growth.…”

“…The genus Meiothermus consists of bacteria that were originally classified as Thermus species but were subsequently found to be phylogenetically distinct from Thermus (Tenreiro et al, 1995;Chung et al, 1997). Meiothermus species are common inhabitants of slightly alkaline aquatic environments ranging in temperatures between 50-85 • C (Spanevello and Patel 2004). The temperature recorded at site CH1 was 56 • C, within the range of temperatures for optimal growth of Meiothermus, and several strains of M. silvanus have been isolated from hot spring environments including a hot spring in Vizela, Portugal, and from Geysir geothermal area in Iceland (Chung et al 1997).…”

Hot springs of Indian Himalayas: potential sources of microbial diversity and thermostable hydrolytic enzymes

“…Members of the Firmicutes (mainly members of families Bacillaceae and Paenibacillaceae) are widely used in agriculture as plant growth promoting and disease suppressing bacteria, besides their use in industry as a source of enzymes and in medicine (Yadav et al 2016a, b). Further, in general the bacteria belong to the genera Bacillus and Thermus were mostly reported as aerobic, heterotrophic thermophiles and found in thermal systems with neutral to alkaline pH (Spanevello and Patel 2004). Though Thermus spp.…”

Temporal and Spatial Differences in Microbial Composition during the Manufacture of a Continental-Type Cheese

“…The presence of Thermus was confirmed by subsequent PCR using Thermus-specific primers (data not shown). This aerobic, marine-associated thermophilic and heterotrophic genus was originally isolated from alkaline hot springs in Yellowstone National Park (51,52). As Thermus has previously been identified in two separate hot water systems, it is conceivable that this bacterium was introduced via a water source (52,53).…”