Growth of Pseudomonas sp. TX1 on a wide range of octylphenol polyethoxylate concentrations and the formation of dicarboxylated metabolites

Abstract Pseudomonas sp. TX1, is able to use octylphenol polyethoxylates (OPEO n , or Triton® X-100; average n  = 9.5) as a sole carbon source. It can grow on 0.05–20% of OPEO n with a specific growth rate of 0.34–0.44 h −1 . High-performance liquid chromatography–mass spectrometer analysis of OPEO n degraded metabolites revealed that strain TX1 was able to shorten the ethoxylate chain and produce octylphenol (OP). Furthermore, formation of the short carboxylate metabolites, such as carboxyoctylphenol polyethoxylates (COPEO n , n  = 2, 3) and carboxyoctylphenol polyethoxycarboxylates (COPEC n , n  = 2, 3) began at the log stage, while octylphenol polyethoxycarboxylates (OPEC n , n  = 1–3) was formed at the stationary phase. All the short-ethoxylated metabolites, OPEO n , OPEC n , COPEO n , and COPEC n , accumulated when the cells were in the stationary phase. This study is the first to demonstrate the formation of COPEO n and COPEC n from OPEO n by an aerobic bacterium.