Strains of the genus Delftia are poorly studied microorganisms. In this work, the complete genome of the naphthalene-degrading Delftia tsuruhatensis strain ULwDis3 isolated from seawater of the Gulf of Finland of the Baltic Sea was assembled. For the first time, genes encoding naphthalene cleavage pathways via salicylate and gentisate were identified in a strain of the genus Delftia. The genes are part of one operon (nag genes). Three open reading frames (ORFs) were found in the genome of D. tsuruhatensis strain ULwDis3 that encode gentisate 1.2-dioxygenase. One of the ORFs is part of the nag operon. The physiological and biochemical characteristics of the strain ULwDis3 when cultured in mineral medium with naphthalene as the sole source of carbon and energy were also studied. It was found that after 22 h of growth, the strain stopped consuming naphthalene, and at the same time, naphthalene 1.2-dioxygenase and salicylate 5-hydroxylase activities were not detected. Later, a decrease in the number of living cells and the death of the culture were observed. Gentisate 1.2-dioxygenase activity was detected from the time of gentisate formation until culture death.

The impact of geographical factors, functional zoning, and biotope type on the diversity of microbial communities and chemical components in the dust of urban ecosystems was studied. Comprehensive analyses of bacterial and fungal communities, polycyclic aromatic hydrocarbons (PAHs), and metals in road and leaf dust in three urban zones of Murmansk and Moscow with contrasting anthropogenic load were conducted. We found that the structure of bacterial communities affected the functional zoning of the city, biotope type, and geographical components. Fungal communities were instead impacted only by biotope type. Our findings revealed that the structure of fungal communities was mostly impacted by PAHs whereas bacterial communities were sensitive to metals. Bacteria of the genus Sphingomonas in road and leaf dust as indicators of the ecological state of the urban ecosystems were proposed.

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.

The degradation of petroleum hydrocarbons by plant-microbial associations, as well as the peculiarities of the interaction between microorganisms in consortium and the associated plants, have been...

The complete genome of the naphthalene- and n-alkane-degrading strain Pseudomonas sp. strain OVF7 was collected and analyzed. Clusters of genes encoding enzymes for the degradation of naphthalene and n-alkanes are localized on the chromosome. Based on the Average Nucleotide Identity and digital DNA–DNA Hybridization compared with type strains of the group of fluorescent pseudomonads, the bacterium studied probably belongs to a new species. Using light, fluorescent, and scanning electron microscopy, the ability of the studied bacterium to form biofilms of different architectures when cultured in liquid mineral medium with different carbon sources, including naphthalene and n-dodecane, was demonstrated. When grown on a mixture of naphthalene and n-dodecane, the strain first consumed naphthalene and then n-dodecane. Cultivation of the strain on n-dodecane was characterized by a long adaptation phase, in contrast to cultivation on naphthalene and a mixture of naphthalene and n-dodecane.