부산대학교 도서관

Growth analysis of E.coli isolated from water when subjected to acidic (2, 3, 4) and basic (8, 9, 10) pH by measuring the optical density for 2 days.: Organisms were isolated (1 Group and 36 samples per group by keeping threshold 0.05% and G power 80% coincidence interval 95% and enrollment ratio as 1) by the serial dilution method and characterizing through biochemical and morphological studies which revealed GDW3 as E.coli. To check the pH effect on bacterial growth, selected isolates were incubated in liquid media for a wide range of pH (2 to 10) for 2 days keeping bacterial growth at 7 as control. In this analysis, bacterial growth was recorded in both low and high pH. Compared to control for acidic pH (2-4) approximately 95% of growth reduction was detected upon 24 hrs of incubation however for basic pH the growth reduction was minimal and it ranges only between 3-7%. For 48 hours of incubation though there is a very small increase of bacterial growth was observed in every pH (3-10%) but for pH 4 a drastic growth reduction of 85% was recorded. On the contrary pH, 10 showed similar output compared to control. The results were found statistically significant p<0.001 E. coli GDW3 can grow both in acidic and basic pH. Under acidic condition pH (2-4) though 95% bacterial growth was reduced initially but was increased up to 10% upon enhancement of incubation time. For basic pH (8-10) initial growth was reduced below 3% and maximized to 7% upon prolonged incubation. [ABSTRACT FROM AUTHOR]