Carotenoid production from n-alkanes with a broad range of chain lengths by the novel species Gordonia ajoucoccus A2^T

A novel diesel-degrading bacterial strain, A2^T, was isolated from soil that was heavily contaminated with oil. Based on phenotypic, phylogenetic, and DNA analyses, strain A2^T was identified as a novel species of the genus Gordonia and named Gordonia ajoucoccus A2^T (KCTC 11900BP and CECT8382). G. ajoucoccus A2^T is able to synthesize carotenoids and produces mainly γ-carotene and keto-γ-carotene. G. ajoucoccus A2^T is also capable of assimilating n-alkanes with a broad range of chain lengths (C6, C8-C25). Batch culture of G. ajoucoccus A2 ^T in a bioreactor containing 1 % (v/v) hexadecane or 1 % (v/v) commercial diesel yielded 25 mg L^-1 and 2.6 mg L^-1 of carotenoids, respectively. Gas chromatography/mass spectrometry (GC-MS) analysis of hexadecane and hexane degradation metabolites suggested that G. ajoucoccus A2^T may possess a terminal oxidation pathway that allows it to utilize n-alkanes and hexane as carbon and energy sources. G. ajoucoccus A2 ^T could therefore serve as a good model system for understanding microbial n-alkane degradation pathways. Additionally, the metabolic capabilities of G. ajoucoccus A2^T suggest potential biotechnological applications, such as the bioproduction of carotenoids from industrial discharge or other sources of n-alkanes.