Biodegradation of low-density polyethylene by Streptomyces albogriseolus UPA11 isolated from a plastic dumpsite

Aim: This study focused on isolating and identifying actinomycetes that degrade low-density polyethylene microplastics. Methodology: For primary screening, low-density polyethylene (LDPE) powder was used with minimal salt medium, followed by growth analysis and clear zone tests to confirm plastic decomposition, and weight loss of microplastic beads with actinomycetes determined degradation after a month of incubation, which was validated using SEM and FTIR. Results: A total of 47 isolates were isolated from several plastic disposal sites located in Rajkot, Gujarat. The results showed that 12 of the 47 isolates were able to generate a zone of clearing and breakdown of LDPE microplastic. Microplastic degradation was most apparent in UPA 11strain (10.1% + 0.6%), as validated by surface modification of the microplastic beads using SEM. Furthermore, 16S RNAsequencing on UPA11 identified the isolate as Streptomyces albogriseolus (OR554013). The presence of phenolic group (O-H) was determined by a new peak between 947.33 and 1219.83 cm-1 using FTIR. Interpretation: The study demonstrated the potential of UPA11, to degrade low-density polyethylene microplastics under laboratory conditions. These findings underscore the potential of UPA 11 for bioremediation of plastic waste, offering an eco-friendly alternative to conventional plastic disposal methods. Key words: Actinomycetes, Biodegradation, Dumping sites, Low-density polyethylene, Microplastic, Streptomyces albogriseolus