Use prospects for microorganisms consortiums and higher plants in oil-contaminated lands restoration
The article presents the research results on the use of microscopic endotrophic fungi cultures in oil-contaminated soils bioremediation. The resistance limits of microscopic fungi Fusarium equiseti (Corda) Sacc and Cylindrocarpon magnusianum Wollenw isolates (cultures), isolated from urban soils with a high level of pollution, were studied to various oil concentrations. Wide limits of microscopic fungi tolerance to oil content were revealed. Also, the cleaning efficiency and restoring the biological activity of oil-contaminated soils was studied using a ameliorants consortium: the biological product «Mikrozim Petro Treat», containing a number of oil degrading bacteria, the plant ameliorant Kentucky bluegrass (Poa pratensis L.) and microscopic fungi. A laboratory experiment was carried out to simulate 5 and 10 % soil pollution (sandy loam and loamy soddy podzolic soils) with oil. The greatest efficiency was established when using the full ameliorants composition with microscopic fungi cultures Cylindrocarpon magnusianum Wollenw (the biological product + plant ameliorant + microscopic fungi): at the end of the experiment, in variants with 5 % oil content on both soil textures and 10 % oil pollution (loamy soil), the oil content was significantly lower than in the control (using only a biological product). On loamy soil at 5 and 10 % oil content, the invertase activity indicator of soils at the end of the experiment exceeded the control in the variant with the use of a combination of ameliorants plant ameliorant + fungi, and maximum - in the variant of the complete ameliorant consortium. These results were obtained using both cultures of microscopic fungi. On sandy loamy soils, a significant increase in the biological activity of soils compared to the control was established only at 5 % oil content and only in the variant using a complete consortium of ameliorants with the fungi Cylindrocarpon magnusianum Wollenw. The results obtained allow us to state the effeciency of the joint application of the biological product, higher plants and microscopic fungi in bioremediation of oil-contaminated soils.