Analysis of the volatile components of a bacterial fermentation attractive to the mexican fruit fly (Anastrepha ludens).

An analysis was performed to identify the volatile components of a supernatant derived from a bacterial (Klebsiella pneumoniae, ATCC 13883, American Type Culture Collection) fermentation of a trypticase soy broth. The bacteria-produced supernatant (BPS) was comparable to a 30% solution of NuLure in attractiveness to mixed sexes of adult Mexican fruit flies, Anastrepha ludens (Loew), in a laboratory bioassay. The volatile components of BPS, most resulting from bacterial metabolism, were identified by a combination of capillary GC and GC-MS techniques. A total of 21 compounds were identified, including 7 alcohols (2 sulfur containing), 8 alkyl-substituted pyrazines, 2 ketones, 2 acids, 1 ketoalcohol, and phenol. The five most abundant compounds, in decreasing order of abundance, were 3-methyl-1-butanol, phenethyl alcohol, 2,5-dimethylpyrazine, 2-methyl-1-propanol, and 3-(methylthio)-1-propanol. One or more unidentified, low molecular weight amines were also present in the mixture of volatiles.