The Screening,identification Of Protein Hydrolyzing Fungi And Application On Food Waste Bio-conversion

With the acceleration of urbanization and growing population in China,there is an increasing buildup of a large number of food waste.City manager have been faced with the serious challenge how to effectively dispose the huge amount of food waste.Food waste is a reservoir of high water and organic matter,which include starches,proteins,lipids,cellulose and other potential components,so the recycle of food waste becomes interest topics globally,for example,converting them to bio-fertilizer,animal feed renewable energy and chemicals.Contrast to traditional food waste disposal methods,fungal hydrolysis possess the greater opportunity to recycle glucose,free amino nitrogen and phosphate etc.So,the screening and isolation of high efficiency food waste biodegrading fungi is premier.In this study,12 fungi were isolated and screened from infected feet which are diagnosed as tinea pedis medically,and 4 fungi which can effectively hydrolyze protein and starch were identified with ITS-5.8s rDNA as Tritirachium oryzae,Paecilomyces sp.181/155FX214Fwat,Aspergillus puniceus and Septoriella oudemansii.In this paper,the optimal temperature,fermentation time and better fungi for submerged fermentation was investigated using high-concentrated protein food waste A.The results showed that the yields of reducing sugar and free amino nitrogen could be greatly influenced by temperature,fermentation time and fungi,and 47? was the optimal temperature,and the yields of reducing sugar and free amino nitrogen of Aspergillus puniceus and Septoriella oudemansii were significantly higher than the rest.Then,solid state fermentation was performed for fungal solid mashes for 5 days using food waste B inoculated with either Aspergillus puniceus or Septoriella oudemansii or mixed Aspergillus puniceus and Septoriella oudemansii.Then,submerged fermentation was performed inoculated with fungal solid mashes.Experiments revealed that the highest concentration of reducing sugar were obtained at 24 h,12080,9832,13123 mg/L,and the maximum yields of free amino nitrogen accumulated at 108 h,3660,2821,3375 mg/L,respectively.Mixed Aspergillus puniceus and Septoriella oudemansii could accelerate the yields of reducing sugar,but do harm to the production of free amino nitrogen.So we believe that Aspergillus puniceus is better for food waste bio-conversion,which could be used in the research of high-concentrated protein food waste for high-added value products.