Bioremediation of MP-polluted Waters Using Bacteria Bacillus licheniformis, Lysinibacillus massiliensis, and Mixed Culture of Bacillus sp. and Delftia acidovorans
Dajana Kučić Grgić, Matija Cvetnić, Tomislav Bolanča, Marinko Markić, Šime Ukić, Kristina Bule, Viktorija Prevarić, Vesna Ocelić Bulatović, Antonija Kovačević, Ema Lovrinčić, Martina Miloloža
Abstract
Microplastic particles (MPs) are widely distributed pollutants in the environment. While a growing number of studies have shown that MPs are toxic to plant and animal life, systemic efforts to reduce their presence have been scarce. Low-density polyethylene (LDPE) and polystyrene (PS) are one of the most common among all plastic-forming MPs. In this study, pure bacterial strains, Bacillus licheniformis and Lysinibacillus <br /> massiliensis, and a mixed bacterial culture of Delftia acidovorans and Bacillus sp., were <br /> used for biodegradation of LDPE and PS microplastics. Biodegradation of MP-PS and <br /> MP-LDPE of particle size 300 – 500 μm was carried out under batch operating conditions at a temperature of 25 ± 2 °C, pH values of 7.15, and 160 rpm during 22 days. The <br /> obtained results showed that mixed bacterial cultures degraded MP-LDPE and MP-PS <br /> better than pure bacterial cultures, and the biodegradation efficiency was higher for MP-LDPE than for MP-PS, as indicated by greater reduction in peak intensity and spectral <br /> deformation, higher colony forming unit (CFU), and inorganic carbon (IC) values.