Bioremediation of petroleum hydrocarbon contaminated soil: a review on principles, degradation mechanisms, and advancements

Abstract

Petroleum hydrocarbons (PHCs) are key energy sources for several industries and daily life. Soil contamination from oily PHC spills is commonly detected in cities and industrial facilities where crude oil is used. The release of PHC pollutants into the environment, whether accidentally from petroleum industries or human activities, has become a leading source of soil pollution. Consequently, the mineralization of PHC-polluted sites has become a central issue worldwide. Although bioremediation is imperative for environmental safety and management, several approaches have been developed for PHC bioremediation. However, much remains to be explored in this regard. This review explores bioremediation of PHC-contaminated soil and provides a comprehensive examination of the principles, degradation mechanisms, and recent advancements in the field. Several microbial species have been used to study the bioremediation of PHCs, emphasizing the pivotal roles of diverse microbial communities. Aspergillus spp., Proteobacteria, and Firmicutes groups of microorganisms were the most efficient in remediating PHC-contaminated soil. The fundamental concepts behind the bioremediation of PHC and the complex mechanisms that govern degradation were elucidated. Limiting factors in the bioremediation process and recent innovations propelling the field were also discussed. Therefore, understanding the degradation pathway, ensuring complete degradation of contaminants, and flexible legislation for the proper use of genetically engineered microbes can make bioremediation more sustainable and cost-effective.

Microbial communities in petroleum refinery effluents and their complex functions

“…Bacteria initiate degradation catabolism of alkanes in aerobic mechanism via oxygenases by four pathways: terminal oxidation, oxidation, subterminal oxidation, and a long-chain n-alkane oxidation pathway. These pathways produce primary alcohols, fatty acids, and β-oxidation, with the final product being n-alkyl hydroperoxide, peroxy acids, alkyl aldehydes, and fatty acids ( Mekonnen et al, 2024 ).…”

“…The sulfate-reducing bacteria strain (Hxd3) is responsible for the development of the carboxylation pathway. This route facilitates the conversion of a C-odd alkane into a C-even fatty acid using subterminal carboxylation at the C-3 position ( Mekonnen et al, 2024 ).…”

“…, Rhodococcus sp., Bacillus sp., and Bacillus pumilus where most of them have been identified as hydrocarbon-degrading bacteria. The biodegradation process is influenced by various factors, including salinity, temperature, pressure, hydrocarbon type (length, aromaticity), pH, hydrocarbon concentrations, existence of other microorganisms, and presence of oxygen ( Liu et al, 2024 , Mekonnen et al, 2024 ).…”

“…Bioremediation activities in general mostly depend on environmental conditions such as temperature, pH, salinity, pressure, and nutrition availability. Temperature is considered one of the main factors that influence the bioremediation process with higher temperatures generally leading to better degradation of petroleum hydrocarbons ( Mekonnen et al, 2024 ). Although there are many studies on the effect of climate change on the bioremediation process, the research on the impact of climate change on the bioremediation of PRE remains limited.…”

Can bacteria and carbon-based nanomaterials revolutionize nanoremediation strategies for industrial effluents?

“…Recent advancements in nanotechnology have shown significant potential in environmental remediation, especially in treating industrial effluents. Integrating CBN with bacteria has emerged as an effective strategy for pollution control (Mekonnen, Aragaw, and Genet, 2024) (Y. Singh and Saxena, 2022c).…”