Physiology and Cell Viability of New Strains of Destructors of Organic Pollutants ^†

Abstract

Every year, people cause more and more harm to the environment as a result of their activities, so the search for new strains of pollutant destructors remains an urgent task. Microbial destructors are the inhabitants of various natural sources: soil, water, etc. We isolated four strains from soil (designated SL-1, 2, 3 and SL-4) and two from river sludge (designated IL-1 and IL-2). The isolation was carried out by the enrichment culture method on a mineral medium containing phenol at a concentration of 0.5 g/L as the sole source of energy and carbon. The pure cultures obtained were tested for their ability to grow on phenol at a concentration of 0.5–2 g/L. The studies showed that strain SL-4 was able to grow on phenol at concentrations of up to 2 g/L, while strains IL-1, SL-1, SL-2 and SL-3 were able to grow on phenol up to 1.5 g/L, and IL-1 was able to grow on phenol up to 0.5 g/L. The new isolates were further tested for their ability to degrade toluene (50 g/L), pinoxaden (50 g/L), a diesel + gasoline mixture, biphenyl and oil. The isolates showed growth on all the substrates used as sole carbon and an energy source, except for strains IL-1, IL-2, SL-1 and SL-3, which are incapable of toluene utilization. The strains were tested for their ability to grow at high salinity. Studies have shown that strain SL-4 is able to grow on a medium with up to 120 g/L of NaCl and the other isolates with up to 100 g/L. The studied strains were also tested for cell viability when growing at high concentrations of phenol and its chlorinated derivatives. The peculiarities of the physiology of isolates and the maintenance of cell viability in unfavorable conditions are important for their further use as a basis for biological products.