Abstract

Young Researchers' Sessions

Day 3, June 12（Wed.）　10:00-10:15　Room B (Convention Hall 200)

When the disinfectant in the tap water is depleted, bacteria start to regrow by utilizing organic matter as substrates. Although the quantity of substrates in tap water has been evaluated, identity of substrate components has not been characterized well. This study performed the non-targeted screening of growth substrates for Pseudomonas aeruginosa, an opportunistic pathogen, dissolved in tap water.
Sterilized tap water with and without inoculation of P. aeruginosa PAO1 was incubated for several days. After incubation, solid-phase extraction was adopted for sample pretreatment, and then non-targeted analysis was performed by Q Exactive Focus (Thermo Fisher Scientific) after online LC separation by InertSustain AQ-C18 (GL Science). Components with significantly lower intensity in inoculated samples compared to non-inoculated samples were screened as substrate candidates. The screened substrates were further analyzed by quadrupole-Orbitrap for structure estimation.
161 substrate candidates were screened from 2381 components in raw tap water samples. Co-chromatography identified five substrate candidates as salicylic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid, which were not found in substrate databases. Of these, four dicarboxylic acids could be utilized as the sole carbon source for the growth. Non-targeted LC/MS analysis successfully discovered novel substrates for P. aeruginosa in tap water.

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