Polycyclic Aromatic Hydrocarbon-Degrading Bacteria in Three Different Functional Zones of the Cities of Moscow and Murmansk

Abstract

We performed a comparative study of the total bacterial communities and communities of cultivable polycyclic aromatic hydrocarbons (PAH)-degrading bacteria in different functional zones of Moscow and Murmansk that were formed under the influence of the PAH composition in road and leaf dust. The PAHs were determined by high-performance liquid chromatography (HPLC); the bacterial communities’ diversity was assessed by metabarcoding. The degraders were isolated by their direct plating on a medium with the PAHs. The PAH total quantity declined in the leaf dust from the traffic to the recreational zone. For the road dust, a negative gradient with pollution was observed for Rhodococcus and Acinetobacter degraders and for their relative abundance in the microbiome for the functional zones of Moscow. The opposite effect was observed in the Murmansk leaf dust for the Rothia and Pseudomonas degraders and in the Moscow road dust for Microbacterium. The PCA and linear regression analyses showed that the Micrococcus degraders in the dust were sensitive to anthropogenic pollution, so they can be used as a tool for monitoring anthropogenic changes in the biosphere. The data on the degraders’ and microbial communities’ diversity suggest that minor degrading strains can play a key role in PAH degradation.

Diversity of Microbial Communities, PAHs, and Metals in Road and Leaf Dust of Functional Zones of Moscow and Murmansk

“…Technogenic compounds of heavy metals and other pollutants coming from enterprises of the power unit are precipitated by wet and dry deposition on the various surfaces [ 43 ]. The functional zoning of cities impacts the total content of PAHs in the biotopes of both Moscow and Murmansk [ 31 ]. The absence of an anthropogenic gradient regarding most of the metals could be associated not only with the accumulation effect as a result of their technogenic nature but also with the presence of similar chemical elements in natural systems [ 6 ].…”

“…The sampling campaign was conducted in the summer of 2021 in two big industrial cities of the Russian Federation located in the subarctic (Murmansk) and temperate continental (Moscow) climatic zones. The meteorological characteristics of the two cities and the conditions preceding the sampling are described in detail in [ 30 , 31 ]. Sampling in Moscow was carried out earlier than in Murmansk with the aim to ensure a similar seasonality and phenological stage of growth of selected tree species.…”

Draft genome sequence of Methylobacterium sp. 37f isolated from forest soil

“…Methylobacterium , a genus of Gram-negative, facultatively methylotrophic bacteria, is commonly found in soil, water, and plants ( 1 , 2 ). These bacteria metabolize a broad range of hydrocarbons ( 3 , 4 ), including isoprene, a climate-active gas, which Methylobacterium can co-metabolize ( 5 ), highlighting their ecological significance.…”