Integrated approach for efficient crude oil bioremediation: Bacterial consortium development, mathematical modelling and scalable bioprocess design

Crude oil pollution has a significant impact on the surrounding ecosystem, making its remediation an urgent necessity due to the waste discharge and seepage from petroleum industries. To address this issue, we developed an efficient bacterial consortium from strains isolated from petroleum refinery waste. These strains were identified as genera Pseudomonas, Ochrobactrum, Alcaligenes, and Bacillus, specifically chosen for their ability to biodegrade crude oil. Through the optimization of process parameters, we enhanced the biodegradation efficiency of the bacterial consortium. Furthermore, the scalability of the biodegradation process was established in 6L batch bioreactor, which featured a total TPH removal of 80.10 %. The independently obtained substrate inhibition data and bioreactor batch kinetics data were utilized to develop a batch mathematical-model. The mathematical model accurately simulated batch bioreactor kinetics and was further extrapolated to design a fedbatch nutrient feeding strategy. Implementing this strategy, based on the model, led to a higher TPH removal rate of 86.86 % in a constant feed batch-fed-batch approach, as validated through experimental implementation. Validation of the biodegradation process was confirmed through Gas Chromatography-Mass Spectrometry (GC-MS) analysis of degraded samples, which confirmed the biodegradation of petroleum hydrocarbons. The increased rates of oil biodegradation achieved through our developed consortium and advanced bioprocess offer a promising solution for the effective clean-up of oily pollutants present in petroleum wastewater and oil spillage scenarios.