engleski

Potential impact of contamination on microbial communities in sediments of Montenegrin coast (southern Adriatic Sea)

Coastal marine sediments are heavily influenced by humans through pollution and thus knowledge of the impacts of pollution upon microbial communities in these environments is important to understand potential effects on coastal areas as whole. The Montenegrin Coast (southern Adriatic Sea) covers a narrow strip of land with the coastline length of 294km, of which 105km belongs to the Bokakotorska Bay, a semi enclosed basin. In recent decades anthropogenic activities (municipial and industrial waste, rapid urbanisation, intesive maritime transport) have led to increased pollution of investigated marine ecosystem, especially in the Bay. The goal of this study was to elucidate bacterial community composition in sediments from twelve sites that ranged in types and level of anthropogenic impacts along coast. The sediments were characterized for a range of physicochemical properties, and microbial community structure was determined by Illumina sequencing of the 16S rRNA genes. Chemical analysis confirmed the high contamination with concentration of polycyclic aromatic hydrocarbon (PAH) and polyhlorinated biphenyls (PCB) at three port stations within Bokakotorska Bay (Port of Kotor, Port of Montenegro and Shipyard Bijela) exceeding the sediment quidelines. Based on average relative abundance Gammaproteobacteria (28%), Deltaproteobacteria (24.4%), Alphaproteobacteria (7.27%) of the Proteobacteria phylum ; Thermoanaerobaculia (7.45%) of the Acidobacteria phylum and Bacteroiidia (6.18%) of the phylum Bacteroidetes were the five largest classes of bacteria in our samples. Gamma- and Deltaproteobacteria were the largest classes in all samples except the most polluted - Shipyard Bijela station where Alpahproteobacteria followed Gammaproteobacteria in abundance. Estuary site Ada Bojana dominated by Gammaproteobacteria and Bacteroiidia. Canonical correspondence analysis (CCA) indicated that PAH, PCB and total nitrogen were the important factors in regulating the bacterial community. The most significant correlation showed Alphaproteobacteria with PAH and PCB (r = 0.91 ; r = 0.88, p< 0.05) and Bacteroiidia with total nitrogen content ( r = - 0.620 ; p < 0.05). Our results indicate that shift in bacterial community composition showed strong associations with environmental variables particularly PAH contaminants

Bacteria ; NGS ; PAH ; PCB ; Sediment

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