Different types of plastic bioremediation using soil bacteria and Superworm zophobas morio larvae

Abstract

Plastic is a recalcitrant molecule that cannot be easily biodegraded. As a result, almost all the plastic that has been manufactured is still in the world. There are microplastics in everywhere like air, water, soil, and specialty foods. A recent discovery suggests we have microplastics in our blood and even microplastics can be transferred from mother to newborn child. There are many types of plastics, and in this research three types of plastics were used, Polyethylene (PE), Low-Density Polyethylene (LDPE), and Expanded Polystyrene (EPS). Two types of samples were used, soil and Zophobas morio larvae. From the soil sample, three types of bacteria were isolated and identified using biochemical tests and ABIS online software where Prolinoborus fasciculus was predominant. These bacteria remained alive for the last six months of incubation in minimal salt broth with only the carbon source being PE. On the other hand, Zophobas morio, a super worm, was used to find out the biodegradation capability in the larvae stage of the insect and also larvae feces bacteria that is responsible for aiding the larvae in digesting the plastics. The larvae consumed 47.07% LDPE, 30.51% EPS, and 26.32% PE in about two months, and in the duration of the experiment no larvae died and they were also seen to recycle their feces. From feces, four bacteria were isolated according to colony morphology that was incubated in minimal salt broth for two months with the sole carbon source being the aforementioned particular plastics, and by doing 16s rRNA sequencing, Pseudomonas guariconensis, and Pseudomonas aeruginosa were identified.