Comparative lipoquinone analysis of influent sewage and activated sludge by high-performance liquid chromatography and photodiode array detection.

Reverse-phase high-performance liquid chromatography and photodiode array detection were used to analyze the microbial quinones of influent sewage and activated sludge in a sewage treatment plant. Significant differences in quinone patterns were noted between the sewage and activated sludge. Unlike the activated sludge, the sewage had low ratios of menaquinones to ubiquinones, and contained menaquinone-6 as the most abundant menaquinone and negligible amounts of partially hydrogenated menaquinones. A photodiode array analysis revealed that the sewage also contained considerable amounts of plastoquinones and vitamin K1, both of which are specific to photosynthetic electron transport in cyanobacteria and chloroplasts. These results suggest that the microbial population structure of sewage is markedly different from that of activated sludge. Relationships between changes in the community structure of the sewage and activated sludge were also discussed on the basis of the results of a numerical analysis of lipoquinone patterns.