Production of the long-chain alcohols octanol, decanol, and dodecanol by Escherichia coli

Abstract

As a follow-up to earlier studies on the emission of long-chain alcohols from broth cultures of Gram-negative enteric bacteria, E. coli was examined for the production of 1-octanol, 1-decanol, and 1-dodecanol. Ten strains of E. coli cultured in tryptic soy broth were assayed for volatile metabolites using solid-phase microextraction. Long-chain alcohols were produced by all strains with 1-decanol predominating with production ranging from 23.6 ng mL(-1) to 148 ng mL(-1). The production of long-chain alcohols followed the onset of the exponential growth phase of the broth culture. Doubling the concentration of glucose (5 g L(-1)) in the broth had no effect on the concentration of long-chain alcohols produced. Addition of octanoic, decanoic, or dodecanoic acids (as K(+) salts) to the broth (100 mg L(-1)) markedly increased the production of the corresponding alcohols by E. coli, ranging from a 13-fold increase for decanol to a 51-fold increase for dodecanol. However, decanol remained the predominant alcohol detected in all assays. These neutral volatile alcohols may have application as vapor-phase indicators for certain classes of bacteria, particularly, Gram-negative enteric bacteria.