Bacterial Remediation of Polyethylene by Serratia marcescens sub sp. marcescens and its Supernatant
Improper disposal of commodity plastics such as polyethylene (PE) in the environment causes land pollution and soil infertility. It is unsightly and strongly threatens plant and animal life. The current effort describes the bacteria-mediated biodegradation of polyethylene by Serratia marcescens marcescens (SM) without prior exposure to thermo-oxidative aging. This study further describes the mechanism involved in the biodegradation of PE, in which a carbonless medium containing essential minerals and vitamins and powdered PE, were placed in the presence of overnight cultures of SM. The samples were incubated at 30°C, centrifuged at a speed of 141 revolutions per minute (rpm) in a rotary shaker for ten weeks in order to observe the degradation process. The effects of cell-free supernatants (from the SM cultures) upon the degradation of sterile PE are elucidated. The results show that the supernatants from SM degrade PE faster than the bacteria, with a 37.5 percent of degradation rate within a month. The SEM micrographs suggest that the biodegradation of polyethylene involves the formation and coalescence of microvoids. The DSC results revealed that the feeding activity of SM is mostly favored at the crystalline region due to its high energy.
Prof. Wole Soboyejo, Dr. Shola Odusunya, Dr. Zebaze Kana, Dr. Nicolas Anuku, Dr. Karen Malatesta and Dr. Mohammed Dauda
S.T. Azeko et al., "Bacterial Remediation of Polyethylene by Serratia marcescens sub sp. marcescens and its Supernatant", Advanced Materials Research, Vol. 1132, pp. 238-251, 2016