Biodegradation of disposable polyethylene by fungi and Streptomyces species

The ability of fungi and Streptomyces species to attack degradable plastics was investigated in pure shake-flask culture studies. The degradable plastic used in this study was disposable polyethylene bags containing 6% starch. Eight different isolated Streptomyces strains and two fungi Mucor rouxii NRRL 1835 and Aspergillus flavus were used. Ten-day heat-treated (70°C) polyethylene films were chemically disinfected and incubated shaken at 125 rpm at 30°C in 0.6% yeast extract medium (pH 7.5) for Streptomyces spp. and for the fungi in 3% yeast extract medium (pH 5.5) for 1, 2 and 4 weeks along with an uninoculated control for each treatment. Active enzymes caused changes in the films’ mechanical properties and weight.