Bioprospecting Evidence of Polyethylene Degrading Bacteria in the Mojo Pemalang Mangrove Rehabilitation Areas

Polyethylene is one of the most widely used microplastic polymers and causes environmental pollution. PE microplastic has durability and low biodegradability, which accumulates in water and sediment, which can inhibit mangrove growth. Damage to the mangrove ecosystem will impact the availability of carbon stocks, sediment stability, nutrient cycles, and shelter. Polyethylene-degrading bacteria are a solution developed to deal with plastic pollution. This research aims to investigate the polyethylene biodegradation potential of bacterial strains from the mangrove rehabilitation area in Pemalang. Sediment and water samples were taken at 15 locations within the rehabilitation area. The bacteria isolate was incubated for 20 days in a test bottle containing a polyethylene pellet and 100 ml of Bushnell Haas media. Degradation was assessed by measuring the decrease in residual mass and the degradation rate of the polyethylene polymer. Isolates A6, A10, SD5, and SD6 were found to degrade the polyethylene pellets with ranges of 1.52% to 5.02% and the removal constants up to 0.08% – 0.26% per day with the half-life of isolates needed around 277.7 – 1115.2 days. The formation of carbonyl groups and cracks in PE can be seen from FTIR and SEM analysis as parameters for degradation. Further research is needed to analyze the enzymatic reactions involved in microplastic degradation.