Bioremediation of petroleum hydrocarbons by alkali–salt‐tolerant microbial consortia and their community profiles

Abstract BACKGROUND Petroleum hydrocarbon pollution has become a global concern, and seeking an appropriate strategy for treatment of petroleum hydrocarbons is necessary, especially under saline–alkaline conditions. In this study, microbial consortia capable of utilizing low‐molecular‐weight aliphatic petroleum hydrocarbons ( n ‐decane, n ‐dodecane and n ‐hexadecane) as the sole carbon source were enriched from crude‐oil‐contaminated soils, and their community profiles were evaluated using high‐throughput sequencing of 16S rRNA gene. RESULTS The microbial consortia were able to degrade 5–100 mL L −1 n ‐decane, n ‐dodecane and n ‐hexadecane by approximately 37.6–97.3%, 52.1–93.2% and 72.4–96.5%, respectively. The consortia also exhibited alkali‐tolerant and moderately salt‐resistant capability, which enabled them to retain high degradation efficiencies of hydrocarbons within a pH range of 7.0–11.0 and salinities of 5–20 g L −1 NaCl. High‐throughput sequencing analysis demonstrated that Pseudomonas , Stenotrophomonas , Achromobacter , Mesorhizobium and Brucella were the core genera (average > 1%) in the consortia, which were more enriched under alkaline condition (pH 11.0). PICRUSt (phylogenetic investigation of communities by reconstruction of unobserved states) prediction revealed a rich set of metabolic functions involved in degradation of hydrocarbons and aromatics, and the critical functional gene, alkane 1‐monooxygenase, was more abundant in the microbial consortia under alkaline condition. CONCLUSIONS The results suggested that these alkali–salt‐tolerant microbial consortia could be a promising candidate for bioremediation of petroleum hydrocarbons. © 2020 Society of Chemical Industry (SCI)