Abstract
The quinone profiling technique was used to investigate the effects of zinc stress on the bacterial population structure of sewage activated sludge in laboratory-scale reactors. The quinone composition of sludges cultivated under different conditions with respect to the sludge retention time and zinc concentrations was determined by thin-layer chromatography, ultraviolet spectroscopy, reverse-phase high-performance liquid chromatography, and mass spectrometry. Numerical analysis of the quinone profiles showed that there were significant differences in the community structure between sludges cultivated with Zn2+ and without Zn2+. When the sludge was loaded with Zn2+, the sludge retention time was also an important factor affecting the quinone composition. The changes in the quinone composition from the normal sludge to the zin-stressed sludges resulted mainly from an increase in bacterial populations with ubiquinone-8 and a decrease in those with partially hydrogenated menaquinones.
