| The development of non-antibiotics feed additives with the characteristics such as safety,effectiveness,stability,good palatability,and harmless to the environment is the top priority of animal husbandry in China.As a kind of functional feed additives,acidifiers have great advantages in many substitutes for antibiotic products.In this paper,the performance of microflora for producing acidifier with low cost and high efficiency was explored.The microflora was enriched from traditional yogurts made by farmers and herdsmen in Xinjiang.High-throughput sequencing comparative analysis of high-yield organic acid microflora was conducted to explore the relationship between bacterial composition and the difference of acid production by fermentation.By reducing the complexity of operation and optimizing the fermentation conditions,to explore a new process of producing compound organic acidifier by microbial fermentation of low-cost raw materials in a wide range of environment.Finally,the effect of organic acidifier produced by microflora fermentation of cottonseed meal-bran on the production index of laying hens was analyzed,which provided a theoretical basis for the application of acidifier.The research results are as follows:1.Analysis of microbial diversity of enriched microfloraThe traditional yoghurts from Xinjiang farmers and herdsmen were used as starter,B2microflora and B5 microflora with high organic acid yield and good antibacterial performance were enriched by MRS medium.Using high-throughput sequencing technology,it was found that there were differences in microbial composition between the two groups,but the dominant bacteria in the two groups were Lactobacillus.2.Production conditions for lactic acid complex liquid acidifier using molasses fermented by microflora enriched from yogurtThrough antimicrobial screening,two microflora with antimicrobial activity were selected for beet molasses fermentation.The fermentation time,fermentation conditions,molasses concentration,nitrogen source and neutralizer were optimized respectively.The results showed that under the optimum conditions,after adding the neutralizer Na2CO3,the lactic acid yield could reach 73.42 g/L,and the total acid yield reached 169.37 g/L.The lactic acid yield and total acid yield of B5 microflora could reach 74.37 g/L and 137.26 g/L after adding the neutralizer Ca（OH）2.B2 microflora fermentation solution has strong inhibitory effect on Salmonella,Staphylococcus aureus and Clostridium perfringens.B5 microflora fermentation solution has strong inhibitory effect on Salmonella,Staphylococcus aureus,Escherichia coli O517 and Escherichia coli STEC.3.Production conditions for lactic acid complex solid acidifier using cottonseed meal fermented by microflora enriched from yogurtThe solid-state fermentation of raw cottonseed meal-bran mixture was carried out by using the microflora enriched from yogurt under natural p H conditions.The substrate type,fermentation time,material-water ratio,molasses concentration,corn steep liquor powder concentration,inoculum amount and neutralizer amount were optimized.Under the optimum conditions,the lactic acid yield of B2 microflora was 106.73 g/kg,the total acid yield was132.18 g/kg,the lactic acid yield of B5 microflora was 100.11 g/kg,and the total acid yield was132.5 g/kg.The fermentation product extract of B5 microflora has strong inhibitory effect on Salmonella enterica,Staphylococcus aureus and Escherichia coli O157.4.Effect of solid acidifier fermented by B2 microflora on production performance of laying hens Adding 2%lactic acid acidifier to the diet of laying hens can increase egg weight,reduce feed-egg ratio,unqualified egg rate and mortality of laying hens to a certain extent.To sum up,microflora B2 and B5 have strong adaptability to a wide range of materials,and can efficiently produce complex organic acids by raw material fermentation,reduce sterilization energy consumption and simplify technological process,greatly reduce the production cost of acidifier,and realize low-cost and efficient production of complex organic acid acidifier. |
