title: Distribution of planktonic bacteria capable of degrading sodium dodecyl sulphate (SDS) in a polluted South Wales river.
abstract: The temporal and geographical distributions of planktonic bacteria, and their ability to degrade sodium dodecyl sulphate (SDS) (AS(+) phenotype), in a polluted South Wales river, is reported for five sites source to estuary sampled during a one-year period. The annual mean prevalence of AS(+) isolates at all sites was 8.1-16.0% of the total number of isolates, and these values were not altered by including SDS in culture media. Although the proportion of AS(+) isolates in clean water at the source was not significantly different to that of polluted sites, the AS(+) cell density was lower at the source because of its lower overall numbers. The percentage of AS(+) isolates in estuarine water was higher than at the three polluted mid-river sites, but when cell numbers were taken into account, the AS(+) cell density was the same at all polluted sites including the estuary. There was no correlation between percentage of AS(+) and either BOD or oxygen concentration, but AS(+) isolates were significantly more prevalent at the end of summer. Of the AS(+) isolates, more than half contained constitute alkysulphate enzymes, the remainder being induced or repressed by SDS; the relative proportions of enzyme regulatory type did not vary significant between sites or at different sampling times.
authors.affiliation: Department of Biochemistry, University of Wales College of Cardiff, PO Box 903, Cardiff, CF1 1ST, UK.
authors.forename: G F
authors.initials: GF
authors.lastname: White
authors.forename: D J
authors.initials: DJ
authors.lastname: Anderson
authors.forename: M J
authors.initials: MJ
authors.lastname: Day
authors.forename: N J
authors.initials: NJ
authors.lastname: Russell