The impact of bio stimulation on oil degradation and microbial community composition in a contaminated desert soil using sewage sludge, soybean meal, and wheat straw

Due to their significant nutrient content and practical economics, waste materials have a strong potential for the bioremediation of oil-contaminated locations. We induced oil deterioration in a highly contaminated desert soil using sewage sludge, soybean meal, and wheat straw. Gas chromatographymass spectrometry-mass spectrometry and other methods were used to monitor changes in the composition of the bacterial community while illumine MiSeq was used to track changes in oil degradation. While the addition of soybean meal had no effect on the amount of CO2 produced given the high respiration activity of the soybean meal alone, the addition of sewage sludge and wheat straw increased the respiration activity to a level 3.2 times–3.4 times greater than in the untreated soil. In the soils treated with sewage sludge and wheat straw, the degradation of almost 90% of the C14 to C30 alkanes was measured. According to MiSeq sequencing, the bulk of the sequences obtained from the untreated soil belonged to Alphaproteobacteria, Gammaproteobacteria, and Firmicutes. The bacterial communities of the soils after the treatments were grouped into distinct clusters by multivariate analysis of operational taxonomic units. The wheat straw treatment showed the most striking change in bacterial populations, with 95%–98% of all sequences belonging to Bacilli. We have come to the conclusion that wheat straw and sewage sludge are effective bio-stimulating agents for cleaning up oil-contaminated desert soils.