[Biodiversity of bacterial isolates on three different media from coking wastewater treatment system]

Bacteria from coking wastewater treatment sludge samples were directly plated on three different isolation media (YPG, LB and WW) and the biodiversity of isolates was examined with DNA fingerprinting. Plate counts with YPG, LB and WW media were 1.6 x 10(6) CFU/mL, 7.0 x 10(5) CFU/mL and 9.8 x 10(5) CFU/mL respectively. 137 single colony isolates were obtained from these three media. ARDRA with enzymes Hinfl revealed 14 operational taxonomic units (OUT) which were dominated by YPG-OTU1 group accounting for 34 isolates and WW-OTU6 group for 25 isolates. The biodiversity of isolates from these two dominant OUT groups was further investigated by a genomic fingerprinting technique, ERIC-PCR. The results indicated that there were 20 different ERIC-PCR types present among the YPG-OTU1 group and only 3 among the WW-OTU6 group. The data showed that the populations of bacteria isolated on three different media were significantly different from each other and a higher degree of genetic diversity was observed among strains isolated from YPG media. So YPG may be recommended to be used for a non-selective medium for isolating more diversified bacteria from wastewater bio-treatment systems.