Population dynamics of phenol-degrading bacteria in activated sludge determined by gyrB-targeted quantitative PCR.
A method for quantifying bacterial populations introduced into an activated-sludge microbial community is described. The method involves extraction of DNA from activated sludge, appropriate dilution of the extracted DNA with DNA extracted from nonintroduced activated sludge, PCR amplification of a gyrB gene fragment from the introduced strain with a set of strain-specific primers, and quantification of the electrophoresed PCR product by densitometry. The adequacy of the method was examined by analyzing the population dynamics of two phenol-degrading bacteria, Pseudomonas putida BH and Comamonas sp. strain E6, that had been introduced into phenol-digesting activated sludge. The density of each of the two populations determined by the PCR method immediately after the introduction was consistent with the density estimated from a plate count of the inoculum. This quantitative PCR method revealed different population dynamics for the two strains in the activated sludge under different phenol-loading conditions. The behavior of both of these strains in the activated sludge reflected the growth kinetics of the strains determined in laboratory axenic cultures.
Watanabe
K
K
Corporate Research and Development Laboratories, Tonen Corporation, Saitama, Japan. kazwata@kamaishi.mbio.co.jp
Yamamoto
S
S
Hino
S
S
Harayama
S
S
D001483:Base Sequence; D001673:Biodegradation, Environmental; D027081:DNA Gyrase; D017931:DNA Primers / Q000235:genetics; D004250:DNA Topoisomerases, Type II / Q000235:genetics; D004785:Environmental Pollutants / Q000378:metabolism*; D005798:Genes, Bacterial; D016946:Gram-Negative Aerobic Rods and Cocci / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D019800:Phenol / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D016958:Pseudomonas putida / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology*; D013045:Species Specificity
D017931:DNA Primers; D004785:Environmental Pollutants; D012722:Sewage; D019800:Phenol; D027081:DNA Gyrase; D004250:DNA Topoisomerases, Type II