High Levels of Endemicity of 3-Chlorobenzoate-Degrading Soil Bacteria

Abstract

Soils samples were obtained from pristine ecosystems in six regions on five continents. Two of the regions were boreal forests, and the other four were Mediterranean ecosystems. Twenty-four soil samples from each of four or five sites in each of the regions were enriched by using 3-chlorobenzoate (3CBA), and 3CBA mineralizers were isolated from most samples. These isolates were analyzed for the ability to mineralize 3CBA, and genotypes were determined with repetitive extragenic palindromic PCR genomic fingerprints and restriction digests of the 16S rRNA genes (amplified ribosomal DNA restriction analysis [ARDRA]). We found that our collection of 150 stable 3CBA-mineralizing isolates included 48 genotypes and 44 ARDRA types, which formed seven distinct clusters. The majority (91%) of the genotypes were unique to the sites from which they were isolated, and each genotype was found only in the region from which it was isolated. A total of 43 of the 44 ARDRA types were found in only one region. A few genotypes were repeatedly found in one region but not in any other continental region, suggesting that they are regionally endemic. A correlation between bacterial genotype and vegetative community was found for the South African samples. These results suggest that the ability to mineralize 3CBA is distributed among very diverse genotypes and that the genotypes are not globally dispersed.

Cosmopolitan distribution of phlD-containing dicotyledonous crop-associated biocontrol pseudomonads of worldwide origin

“…However, soil pseudomonads displayed strong endemicity when considered at intra-species levels using BOX-PCR ¢ngerprints [48]. Similar ¢ndings were obtained with soil bacteria degrading 3-chlorobenzoate [49]. The results from BOX-PCR, RAPD pro¢ling and PCR-RFLP analysis of phlD (i.e.…”

Biogeography of bacteria associated with the marine sponge Cymbastela concentrica

“…Indeed, closely related microbes have been found in widely separated oceanic areas (Mullins et al ., 1995;Hagström et al ., 2000), and it has been suggested that marine microbial diversity is relatively low (Hagström et al ., 2002). In contrast, several recent terrestrial studies have indicated that endemism does exist among bacteria (Fulthorpe et al ., 1998;Cho and Tiedje, 2000;Papke et al ., 2003) and archaea (Whitaker et al ., 2003), but that methods offering high levels of genetic resolution are required for its detection.…”

The phylogeography of Adelie penguin faecal flora

“…The predominant theory in microbial diversity has been that 'everything is everywhere, the environment selects' (Cho and Tiedje, 2000). However, studies of bacteria in symbiotic relationships with eukaryotes and in soils are revealing that endemism exists within the microbial world and bacterial diversification is ongoing (Fulthorpe et al, 1998;Cho and Tiedje, 2000;Funk et al, 2000). Genetic data are increasingly showing that in the microbial world everything is not everywhere, suggesting that the distribution of bacteria can be restricted by factors such as distance between sites (Cho and Tiedje, 2000).…”