Enhanced degradation of petroleum hydrocarbons by immobilizing Acinetobacter

The highly efficient elimination of petroleum pollution is essential for addressing environmental issues and social sustainability. A hydrocarbon-degrading bacterium SHC is isolated from petroleum-contaminated soil in Chengdu, China, to augment bioremediation efforts against crude oil contamination. According to the analysis of 16S rDNA sequences, strain SHC was identified as Acinetobacter. The degradation rate of 2 g/L crude oil by free bacterium reached 30 % within 7 days. Through the analysis of hydrocarbon biodegradation, strain SHC was found to biodegrade more long-chain n-alkanes (C19–C29). Further, we delve into utilizing agar as a microbial immobilization matrix, supplemented with nutrient salts and oil-absorbing materials, to foster the growth and activity of the bacterium in challenging environments characterized by high salinity and acidity. In the final immobilization bacterium, the degradation rate of 3 % salt concentration reaches 22 %, the degradation rate of 5 g/L crude oil is 45 %, and the degradation rate at a pH of 10 is 74 %, and was 59 % more effective than the free bacterium on the removal of crude oil under the same conditions. These findings strongly indicate that encapsulating Acinetobacter SHC can protect them against extreme conditions, bolstering bioremediation endeavors.