Discovering untapped microbial communities through metagenomics for microplastic remediation: recent advances, challenges, and way forward

Abstract

Microplastics (MPs) are ubiquitous pollutants persisting almost everywhere in the environment. With the increase in anthropogenic activities, MP accumulation is increasing enormously in aquatic, marine, and terrestrial ecosystems. Owing to the slow degradation of plastics, MPs show an increased biomagnification probability of persistent, bioaccumulative, and toxic substances thereby creating a threat to environmental biota. Thus, remediation of MP-pollutants requires efficient strategies to circumvent the mobilization of contaminants leaching into the water, soil, and ultimately to human beings. Over the years, several microorganisms have been characterized by the potential to degrade different plastic polymers through enzymatic actions. Metagenomics (MGs) is an effective way to discover novel microbial communities and access their functional genetics for the exploration and characterization of plastic-degrading microbial consortia and enzymes. MGs in combination with metatranscriptomics and metabolomics approaches are a powerful tool to identify and select remediation-efficient microbes in situ. Advancement in bioinformatics and sequencing tools allows rapid screening, mining, and prediction of genes that are capable of polymer degradation. This review comprehensively summarizes the growing threat of microplastics around the world and highlights the role of MGs and computational biology in building effective response strategies for MP remediation.

Freshwater plastisphere: a review on biodiversity, risks, and biodegradation potential with implications for the aquatic ecosystem health

“…Most of the available information on freshwater plastisphere biodiversity comes from culture-independent methods ( Table 1 ), which allow a comprehensive characterization of plastisphere-associated microbiomes. Among them, the use of high-throughput sequencing methods, both as amplicon sequencing of SSU RNA genes and shotgun metagenomic sequencing, are essential to decipher the taxonomic and functional diversity of samples, thus providing the composition and the metabolic potential of the entire microbial community ( Dey et al, 2022 ; Wani et al, 2023 ). Recent developments in sequencing techniques have led to sequence very long reads (up to 50 kb) offering multiple cutting-edge options for understanding microbiome structure and functioning ( Tedersoo et al, 2021 ).…”

Chitinases: expanding the boundaries of knowledge beyond routinized chitin degradation.

“…In aquatic environments, chitin wastes accumulation can disrupt the delicate balance of ecosystems. In areas with extensive chitin pollution, such as near seafood processing facilities or waste disposal sites, negative effects on marine life are evident (Wani et al 2023). For instance, as chitin resists degradation, its slow but eventual microbial decomposition consumes substantial oxygen, creating an imbalance in the ecosystem's oxygen-demanding processes.…”

“…Moreover, chitin-rich waste may provide favorable conditions for the growth of harmful microorganisms, leading to the deterioration of water quality and posing risks to human health (Fig. 2) (Mathew et al 2021a, and references therein;Wani et al 2023). Therefore, addressing chitin pollution requires a multifaceted approach that involves promoting sustainable waste management practices, developing effective recycling technologies, and encouraging the utilization of chitin in various applications.…”

Eco-friendly and safe alternatives for the valorization of shrimp farming waste

“…Microplastics that threaten marine and human life have been reported in P. monodon and Metapenaeus monoocerous (brown shrimp). Thus, shrimp can act as a carrier for microplastics (Hossain et al 2020 ; Nan et al 2020 ), heavy metals (Baki et al 2018 ), and microbial infectious agents (Chen et al 2019 ; Wani et al 2023b ). The waste generation factor for shrimp and fish was estimated at 42% and 32.67%, respectively, accounting for 29,388 tons of waste per year in Bushehr province, Iran (Ravanipour et al 2021 ).…”