ABUNDANCE AND PHYLOGENETIC ANALYSIS OF HIGH-DENSITY POLYETHYLENE (HDPE) BIODEGRADING BACTERIA FROM BRANTAS RIVER, MALANG CITY

Microplastic pollution has become a global concern after Pandemic COVID-19. This requires efforts to resolve the various negative effects of microplastic pollution in the aquatic environment. The purpose of this study was to isolate, enumerate and potency of microplastic biodegrading bacteria from the Brantas River, Malang City. These research steps consist of environmental factor measure, bacterial isolation, enumeration, biodegradation test (qualitative and quantitative) and data analysis. The environmental conditions of the sampling locations are generally homogeneous. The river temperature observed ranged from 24.1 to 27.2 °C. Research locations that have acidity ranging from 7.35 to 8.16. The salinity of the Brantas River ranges from 205-306 ppm or 0.0205-0.306%. The conductivity of the Brantas River ranges from 410-612 µS/cm. Isolation produced 6 different bacterial isolates. The amount of each isolate varies in each sample. Each isolate was characterized according to colony character standards (configurations, margins and elevations) and cells (shape, gram). Microplastic biodegradation qualitative test indicated by the growth of colonies in the plastic area. This indicates that the bacterial isolate uses plastic as a carbon source. All isolates grow around plastic. Quantitative tests using HDPE sheets show that not all isolates are capable of biodegrading microplastics. Bacterial isolates capable of biodegrading HDPE plastic were isolates K2 (5.41%), K22 (5.16%) and K5 (6.69%).