The Effects of Nutrients on the Efficiency of Motor Oil Bioremediation by Pseudomonas putida

Abstract

Bioremediation is an innovative solution to reduce harmful chemicals in the environment using microorganisms and plants, making pollution removal more eco-friendly and cost effective. Nutrients are often applied to enhance the process of bioremediation, allowing for larger, more active colonies of bacteria to grow and consume contaminants. The purpose of this project was to study the limits and effects of adding various amounts of nitrogen, phosphorus, and potassium to the environment of Pseudomonas putida as it consumed hydrocarbons in motor oil. In the experiment, test tubes of water, motor oil, bacteria, and varying amounts of nutrients were observed for two days. At the end of the two day period, the amount of oil left in the tubes was analyzed using a spectrophotometer to calculate the turbidity as absorbance numbers. It was found that there was a distinct negative trend in absorbance with each increase in nutrients, signifying that the nutrients allowed for greater growth and hydrocarbon consumption by Pseudomonas putida. However, there was not an observable limit to the benefits of adding nutrients. This is likely due to Pseudomonas putida’s strong chemotaxis towards hydrocarbons, and not towards other nutrients. Additionally, it was discovered that increasing the potassium promoted more oil consumption, due to potassium’s key role for cellular transportation and moderation of turgor pressure. The results of this experiment can be used to guide which nutrients to prioritize in the bioremediation process, but more research must be done to discover the full extent of adding nutrients to a realistic environment.