Water Quality Assessment and Identification of Novel Bacterial Strains in the Halda River Water of Bangladesh

Abstract

The present study was undertaken to determine a holistic picture of pollution comprising the physicochemical and microbiological properties of the Halda River water of Bangladesh. A total 45 samples were collected from five sampling sites. Different water quality parameters including temperature, pH, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), total dissolved solids (TDS), total solids (TS), turbidity, concentration of heavy metals, total bacterial count (TBC), total coliform (TC), and fecal coliforms (FC) were assessed. Isolation and identification of 10 bacterial isolates was done using their cultural, morphological, physiological, biochemical characteristics, and 16S rRNA gene sequencing analysis. Antibiotic sensitivity of selected isolates was also investigated. DO (6–14.67 mgL−1), BOD (2–8 mgL−1), COD (40.43–107.63 mgL−1), TSS (818.33–3,180 mgL−1), TS (1,039.33–3,897.33 mgL−1), and turbidity (40.09–355 NTU), TBC (7.2 × 103–3.83 × 105 CFU/mL), FC (0.7 × 102–3.9 × 103/100 mL) were measured in both non breeding and breeding time that implies the pollution of the Halda river water. Heavy metal concentration was found within standard limit. Among the isolates, Bacillus wiedmannii strain HSA2 (accession no. MT102620) showed multidrug-resistant, which is a matter of great concern. According to the study findings, the water quality of the Halda river is being deteriorated, posing a threat to public health as well as the aquatic environment.