Characterization of Potential Plastic Degrading Bacterial Isolates for Lipase Production

Abstract

Overproduction of plastics and difficulty to degrade the plastic have become one of the major threats in the environmental sector. This plastic has been reported to accumulate in many different places. Many methods have been used to solve the problem but resulting in other harmful effects toward the environment. Methods by utilizing the enzyme from microbes can be feasible to perform without additional disadvantages to the environment. Among the types of plastic, PET and PU are the plastics which can be degraded by lipase enzymes due to the existence of ester bonds in PET and PU. By using a hydrolysis mechanism, lipase enzymes are capable of cleaving the ester bond present in those plastics resulting in an initial components structure of plastics. In the previous study, several bacteria from Bantar Gebang and Cipayung have been reported to be able to degrade plastic. However, the molecular mechanisms of those bacteria are still unknown. Hence, in this project, we want to screen the potential plastic-degrading bacterial isolates for lipase production by performing agar screening using olive oil and phenol red alongside with the enzyme activity assay using nitrophenyl acetate. From these results, only three sample indicate consistency in both assay which are Leachate_PET_BantarGebang, Leachate_PU_Cipayung, and Plastic_PU_Cipayung with Leachate_PU_Cipayung sample indicate highest lipase activity on both assay. The sample of Leachate_PU_Cipayung is also considered as a gram positive bacteria. Further investigations on species identification are recommended by using specific methodology of 16s rRNA sequencing technology for better identification.