Water paper

             Biological organism are perhaps the most dangerous of the three pollutants since they are responsible for the transmission of disease. Tests for water purity are mainly aimed at detecting particular indicator organisms. Indicator organisms are specific organisms which are present in water and can indicate human waste entering the water (Tortora, et al., 1998). Once these organisms are detected, they can be effectively eliminated, thereby making drinking water safer. For example, if the organism present in human feces is detected in the water, it is good indication that human waste is entering the water and oral fecal transmission can take place. (Tortora, et al., 1998). In the United States, the usual indicator organisms are the coliform bacteria. Coliforms are defined as aerobic or facultative anaerobic, gram negative, non-endospore forming, rod-shaped bacteria that ferment lactose to form gas within 48 hours of being placed in lactose broth at 38degreeC (Tortora, et al., 1998). Of particular interest to food and water standards is fecal coliforms, Particularly Echerichia coli, which is commonly found in plants, soil and large portion of human intestinal track. It can cause severe illness, and even death. In order to determine exactly how safe our water is, an experiment was done with the following hypothesis: Sample C, will test positive for coliform bacteria E. coli. Due to sample C, water turning yellow indicating acid and also presences of gas bubble in Durham tube. .
             II. Material and Methods.
             A. Presumptive Test: Inoculate three Lactose broth tube with 1 ml of water from each of the water sample A, B and C. Incubate at 37 degree C for 24-48 hours. Water sample turing yellow in color is positive for Acid and Bubble in Durham tube shows positive for Gas production in 24-48 hours positive presumptive test. B. Confirmed test includes Eosin ethylene Blue plate, which inhibits gram positive bacteria.