Novel insights into insect mediated polystyrene biodegradation through bacterial genome analyses

Plastic pollution is a significant environmental challenge of contemporary age. Polystyrene (PS), among the most commonly used plastic polymers worldwide, is highly durable and difficult to degrade. Despite various disposal strategies, PS continues to impact biodiversity, human health, and ecosystems. Recently, the scientific community has focused on the potential role of microorganisms for plastic biodegradation, particularly those from the gut of plastivorous insects. In a previous study, three bacterial strains, each representing a distinct taxonomic group (Klebsiella, Pseudomonas, and Stenotrophomonas), were isolated from Alphitobius diaperinus larvae after rearing on a PS diet and enriched in a medium with PS as the sole carbon source. The Stenotrophomonas sp. strain, here identified as S. indicatrix, showed the greatest potential for PS degradation. The present study investigates the genetic profile of the newly isolated S. indicatrix strain DAI2m/c through genome sequencing, to identify enzyme-encoding genes involved in the intracellular metabolic pathways responsible for the biodegradation of the styrene monomer. Our findings indicate that the genome of S. indicatrix strain DAI2m/c encodes all enzymes required for one of the two recognized styrene degradation pathways, suggesting its ability to convert styrene into byproducts that are then utilized for cellular energy production.