Psychrophilic insights into petroleum degradation: Gene abundance dynamics

Petroleum degradation by psychrophiles can be enhanced on the basis of omics analyses, which offer better sensitivity than traditional biochemical methods do. A metagenomic analysis focusing on gene abundance comparisons may provide new guidance to optimize soil decontamination under cold environmental conditions. The soil used in this study was sampled from Dalian, from which an indigenous consortium was isolated. The degradative soil systems, initially categorized into control (DLC) and experimental (DLD) groups, were kept at room temperature (20 ± 5 °C) for six weeks. The DLD group was subsequently transferred to a low-temperature environment (5-10 °C) for 90 days and renamed DDL. A petroleum removal rate of 74.59 % was achieved in the process from DLD to DDL groups. Each soil sample was subjected to analysis and metagenomic sequencing. The abundance of genes of interest was compared between pathways to determine trends. The findings demonstrate that psychrophilic degradation is more effective than natural remediation is. The soil microbial community structure displayed site specificity, with 802 genes in DDL associated with 249 pathways, indicating greater abundance of psychrophilic genes in DDL than in DLC. The abundance of key genes was at different orders of magnitude but showed similar trends. The abundance of genes associated with hydrocarbon-related metabolism surpassed that of genes associated with sphingolipid, fatty acid, or benzene metabolism. This study provides valuable insights into psychrophilic microbe-driven petroleum degradation and indicates the need for precise supplementation of biosurfactants to improve remediation efficiency.