Ecological and physiological analyses of Pseudomonad species within a phenol remediation system

A diverse collection of 700 bacteria obtained from an operational phenolic remediating industrial treatment plant was made to select potential strains as microbial biosensors. Pseudomonads were the most abundant group, of whi ch 48 selected from the liquor or suspended solids were assessed for their physiological response to phenolic pollutant loading and niche specialisati on. By FAME-MIS identification the Pseudomonads were clustered into six maj or species groups. Those isolates able to utilise phenol as a sole carbon s ource predominantly belonged to a non-clonal Pseudomonas pseudoalcaligenes cluster determined by REP-PCR genotyping. Rapid microtitre based respiratio n assays were developed to contrast activity in response to increasing conc entrations of phenol. A considerable range in response for both phenol degr ader and non-degrader strains was observed. This natural phenotypic and phy siological heterogeneity could facilitate the selection of isolates fur the development of a suite of ecologically relevant, custom designed sensors w ith predictable toxicity susceptibilities to monitor process efficacy. (C) 2001 Elsevier Science B.V. All rights reserved.