Dimitrova, KatyaSpasov, SpasBogdanov, NikolovShilev, StefanPetrova, Slaveya2026-01-302026-01-302026-01-251313-9940https://doi.uni-plovdiv.bg/handle/store/975It has been shown that microorganisms associated with the crown of trees (phyllosphere) can improve their ability to purify the air from pollutants. On the one hand, this is due to the metabolites released by the microorganisms that stimulate the development of trees and their resistance to stress, and on the other hand, the microorganisms themselves also are able to degrade some of the atmospheric pollutants. The aim of the present study was to assess the influence of the urban environment on the metabolic activity and functional diversity of microbial communities in the phyllosphere of linden trees, planted in four experimental plots within the city of Plovdiv (Bulgaria). Each plot is characterized by different anthropogenic load, thus allowing for detection of potential specificity of microbial metabolism. A total of 12 saplings of Tilia tomentosa Moench were planted (3 individuals per plot) and leaf samples were collected after 3-month period in the urban environment. Biolog EcoPlate™ of the BIOLOG system (Biolog, Hayward, CA, USA) was used for estimation of metabolic activity of microbial communities, associated with linden trees. The epiphytic communities isolated from leaf samples of Plot 4 (lowest degree of urbanization) showed the highest average-well color development (AWCD) and substrates` metabolic activity. It was found that microorganisms in the two more strongly affected by the traffic locations (Plot 1 and Plot 3) have a higher rate of carbohydrate assimilation and a lower rate of phenolic compounds assimilation compared to the other two locations. Most of the analyzed functional indices showed higher biodiversity and better distribution of substrate utilization in the epiphytic microflora of the leaves of trees planted on Plot 4 (lowest urbanization intensity).enair pollutionurban environmentphyllosphere microbiomeBiolog EcoplatephytoremediationArticle