Establishing and Optimizing a Bacterial Consortia for Effective Biodegradation of Petroleum Contaminants: Advancing Classical Microbiology via Experimental and Mathematical Approach

In classical microbiology, developing a high-efficiency bacterial consortium is a great challenge for faster biodegradation of petroleum contaminants. In this study, a systematic experimental and mathematical procedure was adopted to establish a bacterial consortium for the effective biodegradation of heavy oil constituents. A total of 27 bacterial consortia were established as per orthogonal experiments, using 8 petroleum-degrading bacterial strains. These bacteria were closer phylogenetic relatives of Brevundimonas sp. Tibet-IX23 (Y1), Bacillus firmus YHSA15, B. cereus MTCC 9817, B. aquimaris AT8 (Y2, Y6 and Y7), Pseudomonas alcaligenes NBRC (Y3), Microbacterium oxydans CV8.4 (Y4), Rhodococcus erythropolis SBUG 2052 (Y5), and Planococcus sp. Tibet-IX21 (Y8), and were used in different combinations. Partial correlation analysis and a general linear model hereafter were applied to investigate interspecific relationships among different strains and consortia. The Y1 bacterial species showed a remarkable synergy, whereas Y3, Y4, and Y6 displayed a strong antagonism in all consortia. Inoculation ratios of different strains significantly influenced biodegradation. An optimal consortium was constructed with Y1, Y2, Y5, Y7, and Y8, which revealed maximum degradation of 11.238 mg/mL OD600 for oil contaminants. This study provides a line of evidence that a functional consortium can be established by mathematical models for improved bioremediation of petroleum-contaminated environment.

In Situ Aerobic Bioremediation of Sediments Polluted with Petroleum Hydrocarbons: A Critical Review

Oil pollution has been a worldwide concern especially in environments where treatment is quite difficult to apply. Marine polluted sediments, in particular, constitute one of the most recalcitrant environments for bioremediation and are often the final repository of petroleum contaminants, as a result of runoff and deposition. Aerobic hydrocarbon degraders present in the sediments are tackling the pollution under oxygen-limited or oxygen-depleted conditions. Research has focused on new ways to enhance bioremediation under anoxic conditions, however aerobic bioremediation is faster, and hence more effort should be made to sustain oxygen concentration levels. In this review, the different bioremediation techniques used for the decontamination of marine sediments are briefly discussed, and focus is primarily given to the different oxygenation methods used for enhancing aerobic bioremediation and the aeration methods that are suitable for in situ application, as well as state of the art technologies that make in situ aeration an appealing approach. Based on the technologies analyzed, suggestions are made for sediment bioremediation techniques in different marine environments.

The detection of petroleum contaminants in soil based on multiphoton electron extraction spectroscopy

The fast detection of petroleum contaminants in soil is very important and urgent for environmental monitoring.