In situ detection of alkB2 gene involved in Alcanivorax borkumensis SK2(T) hydrocarbon biodegradation

This study aimed to develop a new assay based on the whole cell hybridization in order to monitor alkane hydroxylase genes (alkB system) of the marine bacterium Alcanivorax borkumensis SK2T commonly reported as the predominant microorganism responsible for the biodegradation of n-alkanes which are the major fraction of petroleum hydrocarbons. The assay based on the whole cell hybridization targeting alkB2 gene was successfully developed and calibrated on a pure culture of Alcanivorax borkumensis SK2T with a detection efficiency up to 80%. The approach was further successfully validated on hydrocarbon-contaminated seawater and provided cells abundance (6.74E + 04 alkB2-carrying cells mL- 1) higher of about one order of magnitude than those obtained by qPCR (4.96E + 03 alkB2 gene copies mL- 1). This study highlights the validity of the assay for the detection at single cell level of key-functional genes involved in the biodegradation of n-alkanes.