Research Of Solid-state Fermentation Of Food Waste With Edible Microbes To Produce Feed Stuff

Because of the special diet custom of Chinese, every year large amounts of food waste was produced. Component analysis shows that most component content of the food waste can reach to the pig feed stuff standard except the crude protein content. Therefore, using the edible microbes to ferment the solid food waste can improve its protein content to make it into protein feed. So in this research, the fermentation effect of some edible microbes was studied. The microbes used in this research include Morchella esculenta, yeast and mold. Different cultivation conditions were designed to process the solid fermentation, then the optimal cultivation strains and its cultivation conditions were determined according to the change of the main nutritious component content. Results obtained are as follows:(1) The solid state fermentation of Morchella esculenta was used to upgrade nutritional value of food waste. Wheat straws and bean dregs are compounded with food waste by different proportion, and Morchella esculenta were used to ferment it. According to the crude protein content after fermentation, the state which was composed by food waste and bean dregs as 1:1 was the best one. When Morchella esculenta was inoculated in this compounded state, the result shows that the optimal fermentation conditions are: incubation temperature of 25℃, natural pH, 65% moisture content, 15% inoculation quantity and 20 days'fermentation time, respectively. Under these conditions, the crude protein content of the substrate increased, all of which exceeded 20%. And the crude fat and crude fiber content of the feedstuff also have changed to some extent. The crude fat content of the feedstuff was lower to 17%, with the content of crude fiber was lower to 16%, and they both are up to standard protein feed stuff.(2)Four edible microbes of Brewers Yeast, Candida, Mucor and Aspergillus oryzae were used to upgrade nutritional value of food waste through solid state fermentation. According to the experiment results, their capacity of upgrading the protein content were arranged as Candida, Aspergillus oryzae, Brewers Yeast and Mucor. And the mixed strains fermentation experiment shows that the combination of Brewers Yeast, Candida, Mucor could be more effective to upgrade the protein content. Experiments of mixed strains shows that the best cultivation conditions are with 55% moisture content, 15% inoculation quantity, 1:1:2 inoculation proportion, 30℃fermentation temperature, 1.5% Urea, and 20 days'fermentation time, respectively.(3)Then a L16(45) orthogonal experiment were processed to optimize the cultivation conditions further more. The result shows that the factors arranged from strong to weak according to their influence to upgrade the nutritional value are moisture content, fermentation time, vaccination proportion, inoculation quantity and fermentation temperature. The K value draws the optimum cultivation conditions as 55% moisture content, 4 days fermentation time, 1:1:2 inoculation proportion, 15% inoculation quantity and 32℃fermentation temperature. Obviously, results of orthogonal experiment are basically the same as the single factor experiment results. Using the optimal cultivation condition obtained from the orthogonal experiment to ferment the food waste, the crude protein content of the substance after fermentation could reach to 28.43%. It is up to the standard of the high-quality protein feed.