Pyrene metabolism by the novel bacterial strains Burkholderia fungorum (T3A13001) and Caulobacter sp (T2A12002) isolated from an oil-polluted site in the Arabian Gulf

• Burkholderia fungorum (T3A13001) and Caulobacter sp (T2A12002) are novel strains isolated from the Arabian Gulf.
• The isolated strains proven to be highly efficient to biodegrade pyrene.
• The isolated strains work efficiently at various temperature and pH conditions.
• The paper provides an important insight into possible PAH biodegradation using those novel strains.

The novel bacterial strains Burkholderia fungorum T3A13001 and Caulobacter sp T2A12002, which were previously isolated from oil-contaminated sites and identified via 16S RNA sequences, were tested for their hydrocarbon degrading efficiency. Media spiked with 100 ppm pyrene were incubated at 25 °C and 37 °C. The bacterial isolates' pyrene-degrading capability was assessed in acidic (pH 5.0) and alkaline (pH 9.0) media. Caulobacter sp degraded 21% and 24% of the pyrene at pH 9.0 and 5.0, respectively; thus, the strain was more active at pH 5.0 than pH 9.0. B. fungorum was active in a wide range of pH values, because it biodegraded 59%–62% of the provided pyrene in acidic and alkaline media. Caulobacter sp degraded 35%–36% of the provided pyrene in cultures at 37 °C and 25 °C. B. fungorum degraded 56% and 59% of the provided pyrene at 37 °C and 25 °C, respectively. Given that B. fungorum biodegraded over the half-life of the initial 100 ppm pyrene in the cultures, the strain may be suitable for bioremediation of high molecular weight PAHs. The study provides important insight into possible PAH biodegradation and bioremediation of hydrocarbon-polluted sites using novel bacterial strains.