The Influence of Remediation with Bacillus and Paenibacillus Strains and Biochar on the Biological Activity of Petroleum-Hydrocarbon-Contaminated Haplic Chernozem

Abstract

The effect of bacterial strains on certain genera, both independently and in combination with biochar in various options, on petroleum hydrocarbon decomposition in chernozem and the restoration of the ecological state of the soil were studied. To simulate petroleum hydrocarbon contamination, petroleum hydrocarbons were introduced into soil in the amount of 5% of soil weight. Strains of Bacillus and Paenibacillus bacteria (in recommended and increased doses × 100) and biochar (1% of soil weight) were introduced into contaminated soil separately and together. It was found that after 30 days, the oil content decreased with the joint introduction of an increased dose of Bacillus, Panibacillus and biochar by 64%, as well as with the inoculation of biochar with Bacillus and Panibacillus bacteria at the recommended dose by 67%. The introduction of biochar, inoculated with BP and BP × 100, contributed to an increase in the intensity of CO2 emission compared to the background by 5–10%. With the joint introduction of BP + B, stimulation was 70%, with an increase in the concentration of BP × 100–115%. The preparation BP and BP × 100 introduced with biochar stimulated the activity of the enzyme by 49 and 61%; with the preinoculation of BP in biochar, stimulation was 27% relative to the background value. The most informative biological indicators when introducing ameliorants of biochar, Bacillus and Paenibacillus were the total number of bacteria, the length of the barley roots and the catalase activity, demonstrating the greatest sensitivity. The results of the study should be used for the remediation and biomonitoring of the state of oil-contaminated soils.