Degradation of Polypropylene Microplastics by a Consortium of Bacteria Colonizing Plastic Surface Waste from Jakarta Bay

Plastics that pollute the environment can be depleted to produce small plastic particles called microplastics. Microplastics have a wide range of negative effects on ecosystem health because they can enter food webs. This study has aimed to assess the ability of a consortium of bacteria colonizing plastic waste from Jakarta Bay to degrade polypropylene microplastics. The plastic waste was collected from 3 sampling points (Muara Kamal, Muara Angke, and Marina) and was enriched in the medium Zobell marine broth for 3d at 27 ˚C, at 125 rpm in an incubator shaker. The obtained bacterial consortium was then tested for their degrading activity on 0.2% polyethylene (PP) microplastics using Mineral Salt Medium (4.5 g/L K2HPO4, 0.2 g/L MgSO4.7H2O, 0.1 g/L CaCl2, 0.1 g/L NaCl, 0.002 g/L FeCl3, 0.1 g/L (NH4)2SO4) at 27 ˚C, 125 rpm for 60d. The results showed that the bacterial consortium degraded PP microplastic in the range of 2.16–6.6% (dry weight basis). Among the three sampling points, the bacterial consortium from Muara Angke exhibited the highest degradation activity. Damage to PP microplastics resulting from the bacterial degradation tests was confirmed using Fourier Transform Infra-Red (FTIR) and Scanning Electron Microscopy (SEM) analyses, which showed the damage to the chemical bonds and the surface of the microplastic. These findings suggest that the Muara Angke bacterial consortium is a viable candidate for PP microplastic remediation while posing no risk to human health or the environment.