EVALUATION OF THE MICROBIAL GROWTH, AS AN INDICATION OF WATER QUALITY, AT VARIOUS FOOD CONCENTRATION

To evaluate the effect of food, which was sugar in this case, on microbial growth, an experiment was conducted using fresh pond water collected from Closter, New Jersey. In this experiment, freshwater samples were collected and brought back to the lab, and mixed with various amounts of 1% sugar solution to simulate the different food amounts added to the system. Using calibrated instruments according to manufacturer’s specification, the samples were checked for weight, temperature, conductivity, percent transmittance, and pH. Then, the number of microbes was observed using the Leica Galen III microscope and recorded because the microbial count could be easily used to estimate the quality of the water. After counting and recording multiple samples, the experiments showed that as the amount of food (sugar) was increased, microbial counts also increased. Algal filaments were found to decrease due to the lack of sunlight in the lab and possibly the production of waste products from the stimulated microbes. Overall, flagellates and ciliates were found to steadily increase as more time passed, and ciliates tended to increase quite a lot as each day passed. It can be concluded that more substances, or wastes are discharged or added to a receiving waterbody, the quality of fresh water can be expected to decrease