Efficient Bioremediation of Petroleum-Contaminated Soil by Immobilized Bacterial Agent of Gordonia alkanivorans W33

Abstract

In this article, we report a method for preparing an immobilized bacterial agent of petroleum-degrading bacteria Gordonia alkanivorans W33 by combining high-density fermentation and bacterial immobilization technology and testing its bioremediation effect on petroleum-contaminated soil. After determining the optimal combination of MgCl2, CaCl2 concentration, and culture time in the fermentation conditions by conducting a response surface analysis, the cell concentration reached 7.48 × 109 CFU/mL by 5 L fed-batch fermentation. The W33-vermiculite-powder-immobilized bacterial agent mixed with sophorolipids and rhamnolipids in a weight ratio of 9:10 was used for the bioremediation of petroleum-contaminated soil. After 45 days of microbial degradation, 56.3% of the petroleum in the soil with 20,000 mg/kg petroleum content was degraded, and the average degradation rate reached 250.2 mg/kg/d.

Sustainable biosurfactant production from secondary feedstock—recent advances, process optimization and perspectives

“…Further experiments showed the stability of these biosurfactants within a temperature range of 20 °C-100 °C and a pH range of 2-12, maintaining the structural integrity up to 550 °C, indicating their potential in bioremediation (Haloi and Medhi, 2019). In a recent study, Yang et al (2023) introduced sophorolipids and rhamnolipids into petroleum-contaminated soil to facilitate the bioremediation of pollutants by Gordonia alkanivorans W33. By mixing the bacteria with sophorolipids and rhamnolipids in a weight ratio of 9:10, significant degradation of the petroleum in the soil was observed.…”

“…By mixing the bacteria with sophorolipids and rhamnolipids in a weight ratio of 9:10, significant degradation of the petroleum in the soil was observed. Approximately 56.3% of the petroleum with 20,000 mg/kg petroleum content was degraded, with an average degradation rate of 250.2 mg d -1 (Yang et al, 2023). The mixture of sophorolipid and rhamnolipid is believed to improve the ability to form microemulsions from wide range of hydrocarbon (Nguyen and Sabatini, 2011).…”

Insights into the Potential Role of Gordonia alkanivorans Strains in Biotechnologies

“…The medium is balanced in such a way that Gordonia strains, when grown on it, yield maximum biomass output. The influence of CaCl 2 and MgCl 2 on biomass growth was described by Yang (2023) [56]. Alkanes were added at 7.5 mL/L, naphthalene, phenol, and benzoate at 1 g/L, and catechol at 0.1 g/L.…”

“…For the strain Gordonia alkanivorans W33, it has been demonstrated that it can degrade 56.3% of the petroleum in contaminated soil within 45 days [56]. Yang and collaborators (2023) note that the efficient remediation of oil-contaminated soil was achieved by increasing the bacteria concentration through high-density fermentation and using vermiculite powder as a carrier, in addition to the inclusion of sophorolipids and rhamnolipids.…”