Biodegradation of plastic by some Microorganisms as influenced by Chemical factors

This study examines microbial and enzymatic biodegradation of plastic, as well as some factors that influence their biodegradability. The results in the present work indicate that the plastic materials could be biodegraded by fungi, like Penicillium chrysogenum and Aspergillus niger for the use of the degradation products economically and the purified enzyme production in different industrial applications. Among 26 fungal isolates obtained, two isolates were identified by molecular tools Penicillium chrysogenum and Aspergillus niger. Different factors affect the degradation rate like carbon source, nitrogen source, metal salt inhibitors, and type of plastic materials. Comparing different carbon sources used in the fermentation medium of Penicillium chrysogenum and Aspergillus niger, glucose was the most suitable carbon source for maximum enzyme production for both fungal strains. Maximum enzyme activities were achieved after the addition of peptone at a concentration of 0.4 % and yeast extract at 0.6 % for two fungi, respectively, as an external supplement of nitrogen sources. Polylactic acid and Polycaprolactone were the most favorable type of plastic for the two fungi to degrade them. Zinc chloride slightly increased enzyme productivity. So, our Search for new fungal isolates capable of degrading plastic materials in soil.