Genetic diversity and biogeography of haloalkaliphilic sulphur-oxidizing bacteria belonging to the genus Thioalkalivibrio

Abstract

A group of 85 isolates of haloalkaliphilic obligately chemolithoautotrophic sulphur-oxidizing bacteria belonging to the genus Thioalkalivibrio were recently obtained from soda lakes in Mongolia, Kenya, California, Egypt and Siberia. They have been analyzed by repetitive extragenic palindromic (rep)-PCR genomic fingerprinting technique with BOX- and (GTG)5-primer set. Cluster analysis was performed using combined fingerprint profiles and a dendrogram similarity value (r) of 0.8 was used to define the same genotype. Fifty-six genotypes were found among the isolates, revealing a high genetic diversity. The strains can be divided into two major clusters, including isolates from the Asiatic (Siberia and Mongolia) and the African (Kenya and Egypt) continents, respectively. The majority (85.9%) of the genotypes were found in only one area, suggesting an endemic character of the Thioalkalivibrio strains. Furthermore, a correlation between fingerprint clustering, geographic origin and the characteristics of the lake of origin was found.

Microbial Biogeography of Six Salt Lakes in Inner Mongolia, China, and a Salt Lake in Argentina

“…The finding that geographic distance affects bacterial biogeography is consistent with the other studies (e.g., references 12, 22, and 51) and has been explained by the fact that, at a long geographic distance, barriers to dispersal are more likely, and so evolutionary events such as speciation and extinction can give rise to differences in two populations separated by such barriers (32). Our finding is consistent with previous studies on Thioalkalivibrio and Salinibacter ruber, which showed that strains of both bacterial species were endemic to certain regions, despite having cosmopolitan distributions (22,58).…”

“…However, due to the small number of studies available thus far, this conclusion should be treated with caution. For example, studies at large-scale distances have been carried out on prokaryotes inhabiting extreme environments, in which the environmental parameters have a relatively small range, and focus on a particular prokaryotic species (22,51,63), while studies at small-scale distances target mixed bacterial populations (14). It is possible that this trend has arisen from the types of habitats sampled or the organism studied.…”

“…To our knowledge, only two studies have looked at the effect of intercontinental geographic distances on microbial community composition in salt lakes. Foti and colleagues looked specifically at the biogeography of Thioalkalivibrio in soda lakes across Mongolia, Kenya, California, Egypt, and Siberia and found that these bacteria showed a tendency for endemism; hence, geographic distance was a significant factor in influencing community composition (22). A further study looked at the biogeography of Salinibacter ruber strains from salterns in the Mediterranean, Atlantic, and Peruvian regions using a metabolomic approach.…”

Influence of salts and pH on growth and activity of a novel facultatively alkaliphilic, extremely salt-tolerant, obligately chemolithoautotrophic sufur-oxidizing Gammaproteobacterium Thioalkalibacter halophilus gen. nov., sp. nov. from South-Western Siberian soda lakes

“…Despite the multiple extreme conditions (pH, alkalinity-salinity, increased irradiation and, sometimes, temperature) in the saline and alkaline lakes, the (micro) diversity of SOB is remarkably high (Foti et al 2006;Sorokin et al 2006b). In the present paper we describe the isolation of a facultatively alkaliphilic and halophilic chemolithoautotrophic sulfur-oxidizing bacterium (strain ALCO 1) from hypersaline soda lakes in S-W Siberia.…”

Physiology and Molecular Phylogeny of Bacteria Isolated from Alkaline Distillery Lime

“…Alkaliphiles are found in natural alkaline environments such as saline soda lakes and ponds of East Africa (Foti et al, 2006), Europe (Gerasimenko et al, 2003), Asia (Antony et al, 2013), Ca 2+ alkaline springs of Near East, and soda deserts of North America (Duckworth et al, 1996). Marine environments contain many alkalitolerant bacteria and usually a smaller number of alkaliphiles (Ntougias et al, 2006;Tamura et al, 2013).…”