Petroleum Depletion Property and Microbial Community Shift After Bioremediation Using Bacillus halotolerans T-04 and Bacillus cereus 1-1

Abstract

Bioremediation of crude oil contaminated environments is an economical, lowmaintenance, environmentally friendly technology and has attracted increasing attention in recent years. In the present study, two efficient crude oil degrading bacteria strains were isolated from soils contaminated with crude oil. Phylogenetic analysis suggested they belonged to genus Bacillus, and were designated as Bacillus cereus T-04 and Bacillus halotolerans 1-1. The crude oil depletion of each strain under different conditions was tested. The optimum conditions for both strains' oil degradation was pH 7, 15-20 g/L NaCl concentration, and 5-15 g/L original oil concentration. The crude oil depletion rate could reach to 60-80% after 20 days of treatment. The crude oil bioremediation simulation tests revealed that the bioremediation promoted the depletion of crude oil to a large extent. The inoculum group with inorganic medium showed the highest crude oil depletion (97.5%) while the crude oil depletion of control group was only 26.6% after 180 days of treatment. High-throughput sequencing was used to monitor the changes of microbial community using different treatments. In all groups, Actinobacteria, Proteobacteria, Firmicutes and Bacteroidetes were the dominant phyla. After contaminated with crude oil, the relative abundance of phylum Actinobacteria was dramatically increased and occupied 81.8%. Meanwhile although strains of Bacillus were added in the bioaugmentation groups, the relative abundance of genus Bacillus was not the most abundant genus at the end of simulation tests. The crude oil contamination dramatically decreased the soil microbial diversity and bioremediation could not recover the microbial community in the short term.

Free and Immobilized Microbial Culture–Mediated Crude Oil Degradation and Microbial Diversity Changes Through Taxonomic and Functional Markers in a Sandy Loam Soil

“…Likewise, Kuang et al (2018) showed that the percentage of Proteobacteria increased in oilcontaminated soil (Shengli oil field, China) compared to unpolluted soil. Nevertheless, Deng et al (2020) reported that after bioaugmentation of Bacillus sp. in crude oil-contaminated soil (Shannxi Province, Yanchang), the original microbial diversity was recovered at the phylum level.…”

Microbiological identification of some culturable native strains associated with the digestive tract in Panaque cochliodon

“…Por otro lado, la capacidad de producir esporas hace que las especies de Bacillus puedan ocupar varios hábitats ofreciendo características importantes en bio-remediación de aguas residuales industriales (35,36), en el cuidado de la calidad del agua en acuicultura (37), en una acuicultura sustentable (37) y de amplio uso como probióticos en diferentes modelos animales (37,38). En peces su aplicación tiene implicaciones directas en mejorar el crecimiento y la conversión alimenticia (38), la resistencia al estrés (38), la inmunoestimulación y resistencia a enfermedades (39) y de manera general en su bienestar (39).…”

Microorganisms Capable of Bioremediation

“…Bacillus cereus Crude oil Degradation [17] Bacillus methylotrophicus Chromate, Glutathione [18] Burkholderia Fungorum PAHs Contaminated Soil [19] Mucor hiemalis Heavy metals [20] Mucor circinelloides Heavy metals [21] Penicillium citrinum, Penicillium pinophilum,…”