Genetic diversity of soil microorganisms assessed by analysis ofhsp70 (dnaK) sequences

Abstract

The genetic diversity of a soil microbial community was assessed by analysis of clonedhsp70 sequences. A clone library was generated by polymerase chain reaction-mediated amplification of a 650-base pair fragment of thehsp70 gene, using DNA extracted from soil, without culturing the microorganisms. Fifty-five random clones were sequenced and their amino acid sequences deduced. Analysis of the amino acid sequence of the clones revealed the presence of signature sequences in common with known prokaryotic and lower eukaryotic HSP70 homologs. None of the 55 analyzed sequences were identical to each other or to a published sequence. These results confirm the presence of considerable genetic diversity within soil microbial communities, the major proportion of which remains uncharacterized.