Chiang Mai Journal of Science

     Ecosystems and the environment are adversely affected by wastewater containing oil and grease, arising from domestic wastes. In this research, lipase-producing bacteria from a wastewater treatment pond were isolated and the ability to remove oils and grease from synthetic wastewater containing 3% cooking oil was examined. The efficiency of using scrub pad immobilized selected lipase-producing bacteria to remove oil and grease from restaurant wastewater was then investigated. Thirty-one bacterial isolates were obtained from the wastewater, and those that produced lipase were selected using Tween 80 agar. Out of all the isolates, the isolate KS915 and KS303 were chosen due to their noticeably high lipase production efficiency of 1.84±0.07 and 1.48±0.24, respectively. The immobilized KS915 and KS303 had the ability to remove 99.85% and 99.76% of the oil and grease from synthetic wastewater supplemented with 3% cooking oil, respectively. The immobilized KS303 was chosen to remove oil and grease from restaurant wastewater because of its shortened removal time in synthetic wastewater. The immobilized KS303 had an oils and grease removal efficiency of 98.37% after two days, compared to 57.78% for the control after more than ten days. The chemical oxygen demand and biochemical oxygen demand of the treated restaurant wastewater decreased by 48% and 92.1%, respectively. The isolated KS303 was identified as Aeromonas jandaei based on 16S rDNA sequence analysis. Based on these findings, A. jandaei KS303 can be a great source of lipase production and remove oil and grease from domestic wastewater.