Manufacturing Of Special Compound Microbial Starter For Maize Straw

Maize straw is a conventional feed resource,mainly composed of lignin,cellulose,hemicellulose,etc.It is a common feed material,but it is directly dried and treated as a diet with poor palatability and low utilization rate.In the current food safety,resource shortage,serious environmental pollution,etc.have become the three major problems facing the livestock industry,protein feed such as soybean meal and fishmeal is in a state of shortage,and the price is gradually increasing.The synergistic fermentation of multi-strain can improve the nutritional value of maize straws,and produce microbial fermented feed with acid odor,easy digestion and high nutritional value.Fermented corn stover can supplement the amino acids lacking in conventional feed,increase the content of bacterial protein,reduce the content of cellulose,hemicellulose and lignin,increase the utilization rate of livestock and poultry,and prolong the storage time of feed.It can effectively promote animal growth,improve production performance,prevent and control animal epidemic,improve economic benefits,and positively affect environmental protection,and promote healthy and sustainable development of animal husbandry.In this experiment,the proliferation medium of Candida utilis,Bacillus brevis,and Bacillus subtilis was obtained by performing response surface optimization test on the culture medium of the existing strain,and a yellow fiber-producing single cell capable of secreting a large amount of cellulase was added.The cytobacteria,the maize straw fermentation test was carried out with four strains of different strains,and the optimal group was selected to optimize the fermentation conditions of maize straw.The test results are as follows:1)The best proliferation medium composition of Candida utilis:the concentration of malt dipping powder is 29.19 g/L,the concentration of yeast dipping powder is 19.30 g/L,and the concentration of K2HPO4 is 2.54 g/L.Under these conditions,the OD₆₀₀ of Candida utilis can reach 0.9597 for 24 h,the average number of viable bacteria is 1.82×108 CFU/mL,and the dry weight of the cells can reach 19.96 g/L,which is the dry weight of the control group.2.3times.2)The optimal growth medium composition of Lactobacillus brevis is glucose concentration of 20.6 g/L,corn syrup addition of 27.19%,and mineral nutrient solution addition of 2.77%.The highest value of OD600 of Lactobacillus brevisii liquid was 3.01,the pH value was 4.08,and the viable count was 1.88×108 CFU/mL.3)The optimized medium composition of Bacillus subtilis was glucose concentration of28.91 g/L,peptone mass concentration of 19.03 g/L,and NaCl mass concentration of 1.78 g/L.Under the conditions of culture for 24 h,the average OD600 value of the fermentation broth of Bacillus subtilis was 2.45,and the viable cell count was 1.68×108 CFU/mL.4)In order to increase the cellulase content in the fermentation broth,add the cellulosin-producing bacteria,and the ratio of the bacteria in the corn stalk compound microbial starter is Candida utilis:Lactobacillus brevis:yellow fiber bacterium:Bacillus subtilis=3:2:1:3.The optimum conditions for the fermentation conditions of corn stover were 0.04%,the fermentation days were 23.71 d and the temperature was 34.56°C.The average bacterial protein content in the fermented corn stover was 15.36 g/L.The crude fiber content of the corn stover sample after fermentation was 30.5%,the acid detergent fiber content was 41.76%,and the neutral detergent fiber content was 25.45%,the acid detergent lignin content was 6.27%.5)The number of live bacteria of the prepared freeze-dried powder product is 2×10¹⁰CFU/g.Each 4 g of freeze-dried powder can process about 10 kg of corn stover,and the composite microbial starter compound test production demand.