Bacterial community analysis of seven polluted lakes in Bangalore, India
This study analyzes the microbial population of seven highly polluted lakes in the Varthur lake series in Bangalore, Karnataka. Unchecked development made Bangalore the center of India’s IT development, which led to a demographic transition. This resulted in a city populated with thirteen million people whose sewage needs could not be met. Due to increased industrial pollution and poor sewage disposal practices, approximately 60% of Bangalore’s sewage goes into the Varthur lake series, primarily into Varthur and Bellandur lakes causing the proliferation of pathogenic bacteria and opportunistic pathogens. Water samples were collected in December 2019 from seven lakes in the Varthur lake series to determine the level of opportunistic pathogens in these water bodies. Nanopore sequencing of 16S rRNA genes identified several pathogenic bacterial strains such as Escherichia coli, Klebsiella pneumoniae, and mycobacterium and industrially important species such as Pseudomonas aeruginosa. The dominant microorganisms found in the Varthur lake series belonged to the phyla Proteobacteria, Bacteroidetes, Firmicutes, and Cyanobacteria. Additionally, all seven samples had fecal indicator organisms indicating fecal contamination. The results of this study indicate the need for drastic and immediate control and remediation measures to reduce neighboring communities’ exposure to these harmful pathogens.