Respiratory quinone profiles as tools for identifying different bacterial populations in activated sludge.

Abstract

Twelve sludges from plants treating sewage or food industrial waste and ten laboratory sludges acclimated to synthetic sewage were investigated for quinone composition. All tested sludges contained both ubiquinone and menaquinone, and some sludges also produced smaller amounts of demethylmenaquinone and/or rhodoquinone. All the sludges had Q-8 as the most predominant ubiquinone, Q-10 as the second homologue, and Q-9 and other ubiquinones as minor components. The menaquinone profiles of the sludges were considerably variable compared with the ubiquinone composition recorded. The gram-negative aerobic bacteria with the Q-8 quinone system were isolated as the most abundant bacteria from the representative sludges tested, corresponding with the results for ubiquinone profiles of the sludges themselves. There was less correspondence in menaquinone profiles between the bacteria and the sludges from which they were recovered. This study describes the applicability of respiratory quinone profiles as tools for identifying different bacterial populations in activated sludge systems.