QUANTITATIVE DETECTION OF ENTEROBACTER-CLOACAE STRAIN HO-1 IN BIOREACTOR FOR CHROMATE WASTE-WATER TREATMENT USING POLYMERASE-CHAIN-REACTION(PCR)

A novel method for the detection of specific microbes using the polyme rase chain reaction (PCR) technique was developed and applied for the quantitative detection of Enterobacter cloacae strain HO-1 (HO-1, here after) in the experimental apparatus used for the treatment of wastewa ter containing hexavalent chromium (chromate). Note that HO-1 is capab le of reducing toxic chromate to trivalent chromium. Based upon the pr eliminary experiments using pUC18 DNA, conditions giving a constant am plification rate of the targeted DNA with high reliability were determ ined for the quantitative detection of its initial concentration by th e extrapolation. The cell density of HO-1 determined by the PCR techni que was compared with the results counted on the selective medium agar plate conventionally used for the counting of HO-1. The procedure pro posed here was successfully applied to estimate the cell density of En terobacter cloacae HO-1 in the bioreactor for the treatment of chromat e wastewater. (C) 1998 Elsevier Science Ltd. All rights reserved.