Biodiversity of streptomycetes isolated from a succession sequence at a post-mining site and their evidence in Miocene lacustrine sediment.
The genetic diversity of streptomycetes in colliery spoil heaps (Sokolov, Czech Republic) was investigated by restriction pattern analysis of 16S-internal transcribed spacer rDNA and 16S sequences. We sampled freshly excavated Miocene sediment (17-19-million-year-old) and four sites of primary succession (initial, early, middle, and late stages; aged 1-44 years) on the same sediment. Active bacteria were present even in fresh Miocene sediment, and the relative proportion of actinomycetes among total bacterial and their genetic diversity increased significantly with the age of the sampling site. The replacement of pioneer species by late succession species during succession was observed. Plate assays of Streptomyces strains revealed 27% antibiotic-producing strains. Screening for nonribosomal peptide synthases and type I polyketide synthases systems suggested that 90% and 55% streptomycetes, respectively, are putative producers of biologically active compounds. The frequencies of tetracycline-, amoxicillin-, and chloramphenicol-resistant streptomycetes were 6%, 9%, and 15%, respectively. These findings document the occurrence of genetic elements encoding antibiotic resistance genes and the production of antibiotics by streptomycetes located in pristine environments. Our results indicate key roles for ancient streptomycetes related to S. microflavus, S. spororaveus, and S. flavofuscus in pioneering community development in freshly excavated substrates.
Chronáková
Alica
A
Biology Centre of the Academy of Sciences of the Czech Republic, V. V. I.-Institute of Soil Biology, Na Sádkách 7, 37005 Ceské Budejovice, Czech Republic. alicach@upb.cas.cz
Kristůfek
Václav
V
Tichý
Martin
M
Elhottová
Dana
D
D000900:Anti-Bacterial Agents / Q000378:metabolism; D044822:Biodiversity; D018153:Czech Republic; D004269:DNA, Bacterial / Q000235:genetics; D019015:Geologic Sediments / Q000382:microbiology*; D008906:Mining; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013302:Streptomyces / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S