Degradation of a mixture of 13 polycyclic aromatic hydrocarbons by commercial effective microorganisms

The study focused on the contribution of effective microorganisms (EM) and their consortia, used in commercial biological preparations and formulations for soil revitalization, to the degradation of a mixture of 13 polycyclic aromatic hydrocarbons (PAHs) commonly found in the soil environment. PAHs, diverse forms of which are present in the environment, never occur individually but always as a part of a chemical mixture. Therefore, the research presented in this article, focusing on the EM impact on the mixture of PAHs, reflects the conditions most similar to natural ones. On Day 35 of the experiment, PAH levels decreased by 75.5-95.5%. The highest PAHs degradation efficiency was achieved for fluorene, with a preparation containing eight bacteria strains from the Bacillus genus: B. coagulans, B. amyloliquefaciens, B. laterosporus, B. licheniformis, B. mucilaginosus, B. megaterium, B. polymyxa, and B. pumilus. All tested preparations containing bacterial consortia and a preparation with the yeast S. cerevisiae intensified the PAHs degradation more effectively than formulations including only the yeast Yarrowia lipolytica or a mixture of Debaryomyces hansenii and Bacillus. The designed and proposed research will contribute to the development of biotechnological methods - bioremediation by microorganisms that are safe for the human and environment health.