| Soybean meal has been concern as a high-quality plant protein source, a variety of sources, nutrient-rich, high value of soybean meal protein utilization. In order to improve the quality of soybean meal feed, we screened a strain of Bacillus subtilis that has strong ability to secrete proteases as the main fermentation bacteria from the nature under anaerobic conditions in our laboratory, which mixed bacteria Saccharomycescerevisiae223 and Lactobacillus plantarum 116 solid state fermentation of soybean meal in feed to increase quality. Solid-state fermentation using a different method of fermentation experiment was conducted to obtain the best soybean meal in the crude protein into small peptides or free amino acids in the fermentation process.This paper conducted the following studies:1. Research on technology of breeding special bacteria fermented soybean. Respectively, screened a high protease strains from the foreign fermented soybean meal, tofu, soy sauce fermentation liquid under anaerobic conditions. After screening and secondary screening, has been stable and efficient performance of fermented soybean meal and predominant strains of NCU646. After biochemical identification and molecular identification of identification, NCU646 been identified as a facultative anaerobic strain of Bacillus(Bacillus subtilis).2. Research on NCU646 anaerobic solid state fermentation process of soybean meal. By L9 (34) orthogonal test fermentation conditions to determine the fermentation conditions of soybean meal NCU646 optimum:the inoculation amount of NCU646 was 6.0g/100g, water ratio was 1:0.8, fermentation temperature was 36℃, fermentation time was96h. In optimum conditions, the fermented soybean meal in the total protein content was increased by 13%, a small peptide content was 9.30 times the pre-fermentation, soybean trypsin inhibitor content from 25.0mg·100g-1 degradation to feed the following content standards of 0.28mg·100g-1.3. Research on Anaerobic bacteria mixed solid state fermentation process of soybean meal. Mixing Bacillus subtilis NCU646, Saccharomycescerevisiae and Lactobacillus fermented soybean meal. Fermented soybean meal were carried out one step and two step Technology of fermented soybean meal.One-step fermentation process:NCU646:Saccharomycescerevisiae: Lactobacillus plantarum=2:1:1 (the bacterial suspension Culture to the growth of the number of mid-weight ratio), inoculum was 6.0g/100g (three kinds of bacterial suspension culture to the growth of the number of mid-weight ratio of 2:1:1 according to the total mass of 6.0g), water ratio was 1:0.8, the fermentation temperature was 36℃, the fermentation time of 96 h. Fermented soybean meal reached 53.51% of total protein, peptide content was 13.20%, organic acid content was 2.19%, dry sample pH values from 6.89 down to 5.32, trypsin inhibitor from 25.0mg·100g-1 degradation to 0.28mg·100g-1 .Two-step fermentation process:NCU646:Saccharomycescerevisiae: Lactobacillus plantarum=2:1:1 (the bacterial suspensionCulture to the growth of the number of mid-weight ratio), inoculation was 8.0g/100g (three bacterial suspension cultured to mid-logarithmic growth of the mass ratio of 2:1:1 according to the total mass of 8.0g), water ratio was 1:0.8, the first step in the fermentation temperature is 30℃, access to Bacillus subtilis and Saccharomycescerevisiae fermented soybean meal, fermentation time 72h; the second step in the fermentation temperature is 36℃under the Access to the first step in Lactobacillus fermented soybean meal Fermentation time of 48h. Fermented soybean meal up to 54.49% of total protein, peptide content was 15.38%, organic acid content was 2.09%, dry sample pH values from 6.89 down to 5.42, trypsin inhibitor from 25.0mg·100g-1 degradation to 0.18mg·100g-1.Comparison of two processes:one-step process with fermented soybean meal fermentation time is shorter, simpler and more operational more economic and other characteristics; two-step fermentation process fermented soybean meal out of the quality of a higher content of small peptides, the total protein content is also higher, better nutritional value.4. Research on mutagenesis NCU646 excellent selection of highly active strains of fermented soybean meal. Re-use of ultraviolet radiation Co-chemical mutagen nitrosoguanidine mutagenic treatment of NCU646 to obtain mutant NCU656. Orthogonal test method using single strain NCU656 solid state fermentation process was studied soybean meal. Solid-state fermentation of soybean meal has been NCU656 techniques:inoculation was 6.0g/100g, water ratio was 1:0.8, the fermentation temperature was 36℃, the fermentation time was 120h. Orthogonal test method using Saccharomyces cerevisiae and plants NCU656 mixed lactic acid bacteria fermentation of soybean meal in the process one step solid-state study. The best technology for:NCU656:Saccharomycescerevisiae:Lactobacillus plantarum= 3:2:1, inoculation 4.0g/100g, water ratio 1:0.8, fermentation temperature 36℃, the fermentation time is 120h. Orthogonal test method NCU656 mixed lactic acid bacteria Saccharomycescerevisiae and plant two-step process for solid state fermentation of soybean meal to study. The best technology for:NCU656: Saccharomycescerevisiae:Lactobacillus plantarum=2:1:1, inoculation 8.0g/100g, water ratio 1:0.8, the first step in the fermentation temperature was 30℃, Bacillus subtilis access Bacillus fermentation of soybean meal and wine Saccharomycescerevisiae fermentation, the fermentation time is 72h; the second step in the fermentation temperature is 36℃under the Access to the first step in Lactobacillus fermented soybean meal, fermentation time of 48h. Mutation compared before and after the nutritional quality of fermented soybean meal and soybean meal to improve the effect of fermented soybean meal derived mutant strain was more significant degradation of small peptides, the success of mutation, with some practical significance. Under the conditions of the fermentation, fermented soybean meal reached 54.39% of total protein, peptide content was 17.01%, organic acid content was 2.10%, dry sample pH values from 6.89 down to 5.44. Degradation of trypsin inhibitors to 0.13mg·100g-1. |
PDF Full Text Request