Optimizing Of Feather Digested Ferme Ntation Conditions And The Effect Of Fermented Products On The Growth Performance Of Larvae Of Black Soldier Fly(Hermetia Illucens L.)

China is a big demand for protein raw materials,however,external dependence of protein raw materials is more than 70%.Especially in the livestock industry,need to import tens of millions of tons of protein raw materials to maintain the normal development of the industry each year,including fish meal,corn,soybean meal and DDGS(Distillers dried grains with solubles)et al.In order to ensure the healthy development of animal husbandry,the development of protein raw material diversity is currently the top priority.C hina's feather keratin resources are very rich,but have not been fully utilized,a large number of feather waste caus ed damage to the environment.From the production costs,energy consumption,nutritional retention,the extent of protein hydrolysis to evaluate the various methods,the comprehensive advantages of microbial fermentation is very prominent.However,even tho ugh more than 30 microbes have been shown to degrade feather keratin,including bacteria,actinomycetes and fungi,these organisms are mostly pathogenic to animals and humans.Therefore,before the discovery of the ideal microbial strains,vigorously study microbial fermentation technology to improve the utilization efficiency of feather keratin,turning waste into treasure.In addition,to study the effective transformation means,The non-directly available keratin degradation products are transformed into another available protein form,such as insect protein.In this paper,the study on the microbial fermentation and utilization of feather waste was carried out.The feather zymotechnique of Bacillus cereus YSQ08 that was selected,isolated,purified by Applied Microbiology Lab of Food Science College of South China Agricultural University is optimized,feed for the larvae of black soldier fly(BSF)(Hermetia illucens L.),to get the insect protein.The spec ific research results are as follows:The growth characteristicsof Bacillus cereus YSQ08showed that:the logarithmic phase is 2~14 h,;the growth period is 8~20 h,the stable period is 22~32 h,after34h is the decline period.In the first half of its growing period,the degradation rate of feathers was about 25.0%,to culture for 14 h,the degradation rate reached 28.68%,then decreased.Bacillus cereus YSQ08 began to secrete Keratinase at the beginning of the growth phase,the secretion peak is about 14h,then secretory activity weakened.In the fermantation conditionsoptimization test,firstly the three factors that had the greatest impact on degradation were identified,including p H value,adding amount of bacterial liquid,adding amount of feathers,days of fermentation,and then by four factors and three levels of orthogonal test L9(3~4).The results of orthogonal test showed that when the fermentation condition was p H7.0,the amount of bacterial liquid was 3.0%,the amount of feather was 3.5%and the fermentation time was 6d,the highest amino acid content reached 90.08mg/L,the degradatio n rate of feather was 32.41%;when the fermentation conditions as follow:p H 8.0,adding amount of bacterium 2.0%,adding amount of feather 3.0%,fermentation time 6 d,then the degradation rate was 34.81%,the content of amino acid was 87.38 mg/L.From the average of each factor,When the pH value was 8.0,the average amino acid content could reach 84.32mg/L,the feather content was 3.0%,the amino acid content was85.25mg/L.The fermentation broth,the supernatant obtained by centrifugation,and the fermentation precipitate were freeze-dried to prepare a dry substance.Among the three substances,the dry matter of the fermentation broth was similar to the precipitate dry matter,they were gray,no special obvious smell,easy to knot.Both are about the protein content of 90.0%and an ash content of about 8.50%,a water content of about 5.05%.Dry matter of the supernatant was soil yellow,no taste,the particles delicate light,not sticky.The crude protein content was 94.36%,the moisture content was 5.36%and the ash content was 3.74%.The above three dry matter were used to feedthe larvae of BSF,feeding by pig manure used as control,the average weight gain,feed weight ratio,conversion rate,survival rate were obtained as the indicators of growth performance.The results showed that the supernatant of cultural broth had the best effect,the average weight gain was 0.2455g,the feed weight ratio was 1.4811,the conversion rate was 40.46%,and the survival rate of the larvae of BSF.was more than 90%.Fermentation broth dry matter,fermentation precipitation dry matter and pig manure in the average weight gain and conversion rate were quite,Average weight gain of about 0.2200g,the conversion rate of about 22%,but the two groups in the feed weight ratio were lower than the pig manure group.In this study,we explored the fermentation conditions of Bacillus cereus YSQ08degradating feathers and the feeding effect of Hermetia illucens L.,proposed a new scheme of a new scheme of resource recycling of feather waste.Feathers through the optimized fermentation process,the protein content of ermentation product was high,made of insect feed to breed Hermetia illucens L..The physical and chemical indicators are not less than the Hermetia illucens L.fed by pig manure,and the breeding efficiency of fermentation supernatant was the best.