Activity of Cobetia marina S2 and Nocardia coeliaca S1 Strains in Oil Hydrocarbons Degradation and Prediction of their Survival after Lyophilization

Abstract

Marine psychroactive microorganisms capable of destructing oil at 4°C have been investigated. The biosurfactant activity and decrease in the oil hydrocarbons content using Cobetia marina S2 и Nocardia coeliaca S1 cultures were determined. Based on the obtained results, it is possible to classify the given strains as promising candidates for components of biopreparations aiming at utilization of oil pollutions in the Arctic area. The investigated cultures were preserved by lyophilization, their stability under those conditions was studied and protective characteristics of various media were compared. It was shown that sucrose in combination with dry skimmed milk is more effective in the protection of C. marina S2 and N. coeliaca S1 during lyophilization than three other investigated media. It was established that the shelf time of the bacteria preparations strongly depends on species; the predicted time of storage of the C. marina-containing preparation using the sucrose+dry skimmed milk medium was 5 months, whereas that for N. coeliaca was equal to at least 100 years. The contribution of the emulsification to the hydrocarbon degradation was also investigated, and a hypothesis of the significance of this process in the microbial utilization of oil contaminations was put forward.