Volatile organic compounds associated with microbial growth in automobile air conditioning systems

Volatile organic compounds from Penicillium viridicatum and Methylobacteriu m mesophilicum growing on laboratory media and on component materials of au tomobile air conditioners were analyzed with gas chromatography and mass sp ectrometry. P, viridicatum produced compounds such as 4-methyl thiazole, te rpenes and alcohols, whereas M. mesophilicum produced dimethyl disulfide, d imethyl trisulfide, and chlorophenol with growth on laboratory media. In co mparison with laboratory media, fewer volatiles were detected from colonize d foam insulation materials. Biofilms of M, mesophilicum on aluminum evapor ator components produced mainly dimethyl disulfide. These biofilms, after i noculation with P. viridicatum, produced offensive smelling alcohols and es ters such as 2-methyl propanol, 3-penten-2-ol, and the ethyl ester of butan oic acid. The moisture and substrates innate to the automobile air conditio ning systems provided an environment suitable for microbial biofilm develop ment and odor production. Reduction of retained moisture in the air conditi oning system coupled with use of less susceptible or antimicrobial substrat es are advised for remediation of the noxious odors.