The effect of environmental pollutants on living organisms can be assessed by studying the changes in the indigenous microbial community. Therefore, in the present study, cultivatable bacterial community in non-polluted as well as household sewage and industrially polluted water of Lai Nullah flowing through Islamabad-Rawalpindi, Pakistan was analysed. Bacterial community composition and population present in the polluted water was significantly different from the non-polluted water (P < 0.05). Non-polluted water had much fewer species and population of bacteria compared to polluted water. Sequence analysis of bacterial 16S rRNA gene revealed that Citrobacter freundii, Klebsiella pneumoniae, Escherichia coli, Lactobacillus plantarum, Geobacillus stearothermophilus, Enterococcus faecalis, Acinetobacter guillouiae, Ralstonia sp., Comamonas sp. and Stenotrophomonas maltophilia were specific to the polluted water. On the other hand, Aeromonas veronii, Exiguobacterium sp. and Lysinibacillus macroides were only found in the non-polluted water. Among measured physicochemical parameters, higher colony count in the polluted water was best correlated with higher biological oxygen demand, phosphate, sodium and chloride values (Spearman's rho = 0.85). Concentration of heavy metals such as cadmium, chromium, copper, nickel and lead were below 0.03μg/mL at all the study sites. During plate assay, bacterial strains found at polluted sites showed resistance to selected heavy metals with highest minimum inhibitory concentration for lead (8mM) followed by copper (5mM), nickel (3mM) and cadmium (1mM). All the bacterial isolates also showed various levels of resistance against antibiotics ampicillin, tetracycline, ciprofloxacin and vancomycin using broth microdilution method. Current research provides new insight into the effect of household sewage and industrially polluted water of Lai Nullah on the indigenous bacteria".
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.