A Fast and Reliable Method for the Analysis of Respiratory Quinones from Environmental Samples using LC/APCI/MS/MS

摘要

The respiratory quinone, ubiquinone (UQ-n, 1-methyl-2-isoprenyl-3,4-dimethoxyparabenzo-quinone) with the 2-isoprenyl chain containing 1 to 14 isoprene (n) units is formed by Gram-negative Proteobacteria during growth with high potential terminal electron acceptors like oxygen and for some species with nitrate. UQ-n are found in eukaryotes with mitochondria. UQ-n are also formed in some purple photosynthetic bacteria growing anaerobically, and a few Actinobacteria. Most Actinobacteria, Gram-positive bacteria and Archaea form menaquinones (MK-n, 1-isoprenyl-2-methyl-naphtoquinone) with the 1-isoprenyl chain containing 0 to 14 isoprene (n) units[1, 2]. The ratios of UQ/MK from environmental samples provide a useful means to probe in-situ redox environment of subsurface microbial communities. The isoprenologue patterns of UQ-n and MK-n provide insight into general community composition [3]. The ratio of respiratory quinones (RQ) to phospholipid ester-linked fatty acids (PLFA) provides a measure of community respiratory activity.