ISOLATION OF POTENTIAL BACTERIAL SPECIES FROM HINDON, GHAZIABAD CONTAMINATED SITE FOR THE DEGRADATION OF HDPE MICROPLASTICS

Abstract

Plastic use has been increased steadily in recent years owing to the urbanization and industrialization at global scale. Microplastic contamination in environment is facilitated through various sources including cosmetic products, drug carriers, glitters and disintegration of larger plastic products such as water bottles and fishing net. Due to their ubiquitous use in the environment, they possess serious threat to terrestrial and aquatic environments and human health. Therefore, it is necessary to degrade microplastics, like HDPE, that are nonbiodegradable and very stable in the environment by using an approach that has negative or no effects on the environment. Thus, in this study, we are isolating the bacterial strains, from the Hindon, Ghaziabad, contaminated site, to check their potential to degrade the HDPE microplastic. Two morphologically different bacterial isolates were selected for further study as they were able to revive in the microplastic containing media. After that, these bacterial isolates were used to study the biodegradation of HDPE microplastic, by growing them in a minimal salt media containing no carbon source. These samples were then maintained for 40 days to observe the growth of bacteria in the presence and absence of microplastic and the extend of degradation of HDPE microplastic by these bacteria. The reduction in weight of the microplastic before and after the incubation was analysed to check the extend of biodegradation of HDPE. The morphological changes of the microplastic were observed using the transmission electron microscope (TEM). The growth curve, total enzyme activity, changes in the pH, laccase activity and many other factors were analysed for this purpose. Therefore, this study could be helpful in assessing the ability of the bacterial isolates to degrade the HDPE microplastic and then further helpful in mitigating the HDPE microplastics pollution.