Biodegradation of starch blended high density polyethylene using marine bacteria associated with biofilm formation and its isolation characterization

The biofouling and biodegradation of starch blended high density polyethylene (HDPE) was studied by immersing it in Bay of Bengal (India) for a period of six months. A positive correlation was observed amongst the various constituents in the biofilm. FTIR spectrum showed the formation of C-O stretching band and decrease in ester and keto carbonyl bands indicating biodegradation. 17% weight loss was observed, while the polymer surface turned hydrophilic. Twenty two bacterial strains were isolated from the biofilm and biochemically characterized. 16sRNA sequence analysis was performed for three strains. In vitro biodegradation of the polymer exposed to sunlight for 150 days incubated with the isolated pure strain (Exiguobacterium) and combination of two strains (Exiguobacterium and B. subtilis) for 75 days, showed a gravimetric weight loss of 4.7 and 12.1% respectively indicating synergy between the two organisms. The current study indicated, the isolated microorganisms could degrade starch blended HDPE. © 2014 Muthukumar T, et al.