Activation of indigenous bacteria for rapid degradation of medium-chain and long-chain hydrocarbons in petroleum-contaminated soils

Abstract

To explore the rapid degradation of medium-chain and long-chain alkanes (C₂₀-C₄₀) in petroleum-contaminated soils by activating indigenous bacteria, as well as the degradation mechanism, a 30-day biodegradation experiment was conducted by adding different proportions of activators (glucose, sodium acetate). The results showed that the removal of total petroleum hydrocarbons (TPH), medium-chain, and long-chain alkanes in the activation group reached 9753.06 $\text{mg}/\text{kg}$, 4185.85 $\text{mg}/\text{kg}$, and 3778.15 $\text{mg}/\text{kg}$, respectively, which were significantly higher than those of the inactive group. Furthermore, the microbial community of the activation group was dominated by Mycobacterium (14.55 %) and Pseudarthrobacter (13.95 %). The activation group consumed a large amount of DOC (10,052.64 $\text{mg}/\text{kg}$), activating Mycobacterium and Pseudarthrobacter to actively uptake oxygen, and significantly increased the activities of dehydrogenase and lipase,which accelerated the transformation of hydrocarbons. This may be the reason why the activation group achieved rapid TPH degradation. Furthermore, predictive modeling using three machine learning algorithms demonstrated strong concordance with experimental data, validating their utility in optimizing bioremediation strategies. This study presents a cost-effective and sustainable approach for the efficient remediation of petroleum-contaminated soils, supported by data-driven insights.