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Five novel acid-tolerant oligotrophic thiosulfate-metabolizing chemolithotrophic acid mine drainage strains affiliated with the genus Burkholderia of Betaproteobacteria and identification of two novel soxB gene homologues

Bhowal, Suparna, Chakraborty, Ranadhir
Research in microbiology 2011 v.162 no.4 pp. 436-445
Allochromatium vinosum, Burkholderia cepacia, Burkholderia pyrrocinia, Burkholderia vietnamiensis, acid mine drainage, acid tolerance, bacteria, genes, nucleotide sequences, phylogeny, ribosomal RNA, sequence analysis, sulfite dehydrogenase, thiosulfates, India
Five acid-tolerant thiosulfate-metabolizing bacteria were isolated from acid mine drainage samples from Garubathan, India. 16S rRNA gene analysis revealed that the strains were affiliated with the genus Burkholderia of the class of Betaproteobacteria. Comparative 16S rRNA gene sequence analyses indicated that the strains designated as GAH1 and GAH2 produced a separate phylogenetic branch having Burkholderia pyrrocinia ATCC 51958ᵀ (96–98%) as the closest relative. Strains GAH4 and Burkholderia tropica Ppe8ᵀ (93%) branched out separately in the phylogenetic tree. Strain GMX2 was most closely related to Burkholderia cepacia ATCC 25417ᵀ (99.6%) and Burkholderia vietnamiensis LMG 10929ᵀ (99%). Strain GAH5 was most closely related to B. pyrrocinia ATCC 51958ᵀ (98%). Oligotrophy has been demonstrated in all AMD strains of Burkholderia spp. All strains showed chemolithoautotrophic and mixotrophic growth in thiosulfate. Furthermore, cell-free extracts of all test strains possessed thiosulfate and sulfite dehydrogenase activities. Phylogenetic analysis of the soxB gene revealed that GAH4 and GAH2 strains formed a novel cluster, Betaproteobacteria II, having highest similarity with Allochromatium vinosum, a member of Gammaproteobacteria II.