Model experiment to assess the effect of oil-destructor strain Pseudomonas schmalbachii N3.1 and remediant plants on the biological activity of soil contaminated with oil and herbicides
T.Yu. Korshunova, L.A. Kulbaeva, E.V. Kuzina, M.G. Iskuzhina, G.F. Rafikova, S R. Mukhamatdyarova
Section: Remediation and rehabilitation
The increasing demand for energy sources is leading to greater contamination of soils, including agricultural, by oil products. It requires the search for effective methods to restore the disturbed territories. This study evaluates the effectiveness of using the hydrocarbon-degrading strain Pseudomonas schmalbachii N3.1, both individually and in combination with Lupinus albus L. and Avena sativa L. plants to purify soil from oil that has been contaminated with imazethapyr- or tribenuron-methyl-based herbicides. The study analyzes changes in the abundance of microorganisms (ammonifying, hydrocarbon oxidizing, oligonitrophilic), soil respiratory and enzyme activity, as well as the soil content of oil products. It was found that oil is less toxic to the soil microbiocenosis than the herbicides, while the combination of plants and bacteria significantly increases the number of microorganisms of the studied groups. When L. albus and bacteria were applied separately, soil respiratory activity in oil-contaminated samples increased by 31–36 %. The highest catalase activity was recorded in A. sativa plantings, including inoculated soils (8.72–12.25 and 9.12–10.95 ml O2/g·min, respectively). Bioremediation promoted an increase in invertase activity (by 1.7–3.5 times), with the maximum effect observed when plants and microorganisms were combined (2.44–4.37 and 2.09–4.51 mg glucose/24 h/g in soils with L. albus and A. sativa, respectively). All types of bioremediation reduced the oil product content in soils. The lowest values were achieved with the combined use of P. schmalbachii N3.1 and A. sativa (2.3–2.8 g/kg). This was probably due to the highest number of hydrocarbon-oxidizing bacteria (up to 13·107 CFU/g) and significant catalase activity (up to 11 ml O2/g . min).
ISSN 1995-4301
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