EXPLORATION OF BACTERIAL POPULATION PRESENT IN GROUND WATER SAMPLE

Gourab Debnath, Paramadatta Das, Rimi Singha, Mousumi Goswami, Shukdeb Acharjee*, Manash C. Das*

ABSTRACT

Water is a basic need for daily life, and its safety directly affects human health. This study focused on Hapania (Women's Polytechnic) and nearby residential houses to evaluate the microbiological quality of drinking and utility water sources. Water samples were cultured using broth and nutrient agar and incubated at 37°C for 24 hours to detect microbial growth. The presence of colonies indicated microbial contamination. Colony Forming Units (CFU) were calculated to estimate the number of viable bacteria per 5µl of each sample. Gram staining was performed to identify the shape and type of bacteria, and the catalase biochemical test was carried out for further identification. The results revealed varying levels of contamination among different locations. Drinking water samples generally showed lower bacterial counts, with Sample 1(House 1) recording the lowest count of 0.4 CFU/5µl and Hapania showing 3.2 CFU/5µl. However, Sample 3(House 3) drinking water showed significantly high contamination with 216 CFU/5µl. Utility water samples consistently exhibited higher bacterial counts compared to drinking water, ranging from 9.6 CFU/5µl at Hapania to a maximum of 376 CFU/5µl in (Sample 3) House 3. (Sample 1) House 1 and (Sample 2)House 2 utility water samples also demonstrated elevated counts of 147.4 CFU/5µl and 42.6 CFU/5µl, respectively, indicating considerable microbial presence. Microscopic examination showed both Gram-positive cocci and rods, along with Gram-negative comma-shaped bacteria, including Escherichia coli, detected in the Hapania utility water sample. The catalase test indicated that most isolates were catalase-positive, suggesting the probable presence of Staphylococcus species, while catalase-negative results in certain samples pointed toward possible Streptococcus species. Overall, the findings highlight that although some drinking water sources showed relatively low contamination, several utility water samples showed high microbial counts. The presence of potential pathogenic bacteria highlights the urgent need for regular monitoring, better sanitation practices, and effective water treatment to reduce the risk of waterborne infections and ensure safe water consumption within the Hapania (Women's Polytechnic) and nearby areas.

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