RUDN ecologists discover bacteria that decompose toxic substances in urban environment

RUDN ecologists, together with colleagues from the Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, have discovered bacteria that can decompose toxic substances in urban dust. The activity of these bacteria can be used to judge the ecological situation in the city. The results are published in Microorganisms 

Polycyclic aromatic hydrocarbons (PAH) are organic compounds that have two or more benzene rings. They are formed during the combustion of hydrocarbons during forest fires, are found in car exhausts and industrial emissions. PAHs have carcinogenic and mutagenic properties. Bacteria, some of which are able to consume PAHs, are helping to partially solve this problem. However, this ability has been studied to a greater extent only in soil bacteria. The ability of bacteria inhabiting urban dust remains unknown. This issue was investigated by RUDN University ecologists.

“Pollution of the urban ecosystem with PAHs is a serious problem. Their accumulation in the environment is of great danger, because many of these compounds are toxic and carcinogenic. PAHs are part of fine dust, one of the most harmful pollutants in the urban environment. Microorganisms also live on dust particles. Bacteria capable of degrading PAHs reduce the concentrations of these compounds in the environment. The role of such bacteria in soils is already well understood. However, bacteria capable of decomposing PAHs and living in urban dust have not yet been studied,” Maria Korneykova, PhD, Senior Researcher at the Smart technologies for sustainable development of urban environment in the conditions of global change at RUDN University.

Scientists compared the composition of PAHs on the road and in the leaves of trees in two large cities – Moscow and Murmansk. Using DNA analysis, the authors determined which bacteria live on the dust particles. There were 27 species of bacteria capable of decomposing PAHs in Murmansk and 15 species in Moscow. As for the PAHs themselves, their concentration and composition turned out to be different on the leaves and in the road dust.

Using the statistical analysis of the results by the method of “principal components”, ecologists found out that bacteria of the genus Micrococcus, capable of decomposing PAHs, are sensitive to anthropogenic pollution. From this, it was concluded that bacteria of this genus can be used to monitor environmental pollution.

“The results of our research allow us to answer the question of how many bacteria that can cleanse the environment are part of the microbial community,” Maria Korneykova, PhD, Senior Researcher at the Smart technologies for sustainable development of urban environment in the conditions of global change at RUDN University.