Detailed studies on microbial adhesion and degradation of polystyrene foam wastes (PSFW) for clean environment

The present study explores the efficient management of non-degradable polystyrene foam wastes (PSFW) by transforming into a microbial responsive material for an effective biodegradation process. In brief, the study involves three steps, viz., (i) preparation of citrus fruit peel extract from peel wastes; (ii) dissolution of PSFW using the extract and transform to polystyrene sheet (PSS) and characterization of the sheet formed and (iii) finally the microbial adhesion and biofilm formation on PSS. Results revealed that the maximum yield of the peel extract identified as D-limonene was obtained from Citrus sinensis (8.2 ± 0.06 ml/100 g fresh waste). Characterization studies on PSS suggested that there are appreciable changes in the infrared spectrum, thermo gravimetric analysis, gel permeation chromatography analyses, and contact angle measurements in comparison with PSFW. Observations on significant variations in the glass transition temperature of PSFW (100 °C) and PSS (60 °C); decomposition temperature of PSFW (310.93 °C) and PSS (78.18 °C), and molecular weight distribution changes in PSFW (2.00 Mw/Mn) and PSS (1.03 Mw/Mn) suggested the occurrence of structural and molecular changes in PSS. Studies on microbial adhesion and biofilm formation on PSS suggested that amongst six microbial species isolated from the waste dump yard, WD03 strain identified as Lysinibacillus sp., displayed a maximum adhesion and biofilm formation on the surface of the PSS as evidenced through biofilm characterizations, SEM, and fluorescence microscopic analyses respectively. In conclusion, the transformation of PSFW to PSS and the appreciable microbial adhesion and biofilm formation suggested the possibility of the effective management of white nuisance (PSFW) wastes in the environment.