The initial interest in metabolite profiling of the cookie samples was to look for the presence of anaerobic hydrocarbon degradation metabolites, based on the knowledge that hydrocarbons in fuel can provide a suitable carbon source for microbial degradation (Davidova & Suflita 2005). Previously, a series of n-alkane biodegradation metabolites (methyl- to butyl-succinates) had indeed been detected by GC/MS in samples from the same production facility