The Effects of Bacillus Thuringiensis and Lysinibacillus Sphaericus on Low-Density Polyethylene

Abstract

The purpose of this research is to determine and compare the rates that Bacillus thuringiensis, Lysinibacillus sphaericus, and a composite of the two degrade low-density polyethylene (LDPE), the global leading plastic pollutant. The research involved measuring the mass of LDPE degraded by B. thuringiensis, L. sphaericus, and a composite of the two. The bacteria agars were inoculated to make a bacterial broth of each culture. Samples of LDPE were exposed individually to B. thuringiensis broth, L. sphaericus broth, and a composite mixture for nine days. Six separate, identical trials were executed, and all were subjected to the same environmental conditions. The masses of all samples were measured and compared to respective masses before exposure to calculate mass degradation. The research and subsequent data obtained present the conclusion that the bacterial composite has a significantly greater degradation rate on LDPE than the B. thuringiensis and L. sphaericus independently. The data furthermore showed an insignificant difference in degradation rates between B. thuringiensis and L. sphaericus individually. The results propose the potential of further developing more effective compositions of microorganisms to degrade polyethylene beyond the rate of the composite examined in this research to reduce global plastic pollution that plagues the environment.