固态发酵马铃薯渣生产活性蛋白饲料的研究

发布时间：2018-03-31 02:18

  本文选题：固态发酵　切入点：马铃薯渣　出处：《西北农林科技大学》2015年硕士论文

【摘要】：我国是马铃薯生产大国,在利用马铃薯加工淀粉过程中会产生大量薯渣,其饲用价值低且会造成环境污染,通过微生物发酵作用能够有效改善马铃薯渣的营养价值,从而提升薯渣饲用价值。本研究以马铃薯渣为主要发酵基质,麸皮为辅助原料,通过多种微生物固态发酵方式生产活性蛋白饲料,分别从发酵菌种的选择及配伍、发酵培养基配比的选择及优化、发酵条件的选择及优化三个方面对发酵马铃薯渣产活性蛋白饲料进行系统的研究。主要结论如下:(1)在单一菌种发酵试验中,黑曲霉HF3与Z9将马铃薯渣发酵后蛋白质含量、蛋白酶活和纤维素酶活显著增加,粗纤维含量显著降低,可用于发酵马铃薯渣产活性蛋白饲料的优良菌种为黑曲霉HF3与Z9。(2)在双菌组合发酵试验中,综合各营养指标和活性指标含量,包括蛋白质、粗纤维含量以及纤维素酶、蛋白酶的活力,得到发酵马铃薯渣产蛋白饲料的优选双菌配伍为黑曲霉Z9和啤酒酵母PJ,最适菌种比例为1:1,发酵4d后,发酵产物中粗蛋白含量达到(41.72±0.58)%,粗纤维含量达到(8.47±0.11)%,蛋白酶活达到(1344.93±10.56)U/g,纤维素酶活达到(120.87±0.46)U/g。(3)在固态发酵培养基优化试验中,得到的培养基配比为马铃薯渣80%,尿素添加量5%,料水比1:1.5,麸皮添加量15%。同时,三个因素对粗蛋白含量的影响主次顺序为:尿素添加量料水比麸皮添加量,对蛋白酶活和纤维素酶活的影响主次顺序为:料水比尿素添加量麸皮添加量;在优化的培养基条件下薯渣发酵后,粗蛋白含量为(38.01±0.80)%,蛋白酶活为(1593.03±5.29)U/g,纤维素酶活为(112.36±1.74)U/g。(4)固态发酵工艺参数优化中得到的发酵条件为料层厚度2cm,发酵时间5d,发酵温度27℃;同时三个因素对粗蛋白含量的影响主次顺序为:发酵温度料层厚度发酵时间,对蛋白酶活的影响主次顺序为:料层厚度发酵温度发酵时间,对纤维素酶活的影响主次顺序为:料层厚度发酵时间发酵温度;在优化的工艺参数下薯渣发酵后,粗蛋白含量为(41.24±1.04)%,蛋白酶活为(1376.19±43.45)U/g,纤维素酶活为(124.33±0.28)U/g,并且各种氨基酸含量大幅度提高,饲料品质得到提升。
[Abstract]:China is a large potato producing country, which will produce a large amount of potato dregs in the process of processing potato starch, and its feeding value is low and will cause environmental pollution. The nutritional value of potato residue can be improved effectively by microbial fermentation. In this study, potato dregs were used as main fermentation substrate and bran as auxiliary raw material to produce active protein feed by solid state fermentation of many microorganisms, respectively from the selection and compatibility of fermentation bacteria. The selection and optimization of fermentation medium, the selection of fermentation conditions and the optimization of fermentation conditions for the production of active protein feed from fermented potato dregs were systematically studied. The main conclusions are as follows: 1) in a single strain fermentation experiment, After fermentation of potato residue by Aspergillus Niger HF3 and Z9, the protein content, protease activity and cellulase activity increased significantly, while the crude fiber content decreased significantly. The best strains for producing active protein feed from potato dregs were Aspergillus Niger HF3 and Z9.2. in the combination fermentation experiment, the nutrient and activity indexes, including protein, crude fiber content and cellulase, were synthesised. The protease activity, the optimum combination of double bacteria for protein production from potato residue was aspergillus Niger Z9 and beer yeast PJ, the optimum proportion of strain was 1: 1, after fermentation for 4 days. The crude protein content in fermentation products reached 41.72 卤0.58, crude fiber content reached 8.47 卤0.11, protease activity reached 1344.93 卤10.56 U / g and cellulase activity reached 120.87 卤0.46 UP / g in solid state fermentation medium. The results showed that the proportion of the medium was: potato residue 80, urea 5, feed to water 1: 1.5, wheat bran 15. Meanwhile, the order of three factors affecting crude protein content was as follows: urea feed and water content was higher than wheat bran addition, and the effect of three factors on the crude protein content was as follows: the ratio of urea to water was higher than that of wheat bran. The order of the effect on protease activity and cellulase activity was as follows: the amount of wheat bran was added in the ratio of feed to water to urea, and the fermentation of potato dregs was carried out under the optimized culture medium. Crude protein content was 38.01 卤0.80%, protease activity was 1593.03 卤5.29 U / g, cellulase activity was 112.36 卤1.74 U / g 路L ~ (4)) the fermentation conditions were as follows: material layer thickness 2 cm, fermentation time 5 days, fermentation temperature 27 鈩，

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