【作者】 刘星斌；

【导师】 张宗舟； 蔺海明；

【作者基本信息】 甘肃农业大学 ， 作物栽培学与耕作学， 2008， 硕士

【摘要】 通过对小麦秸秆生物降解生产蛋白饲料的研究。目的在于对可再生资源的生物转化利用,拓广饲料来源,提高饲料质量,使其作为一种清洁产业促进农业的可持续发展。工作主要在筛选出高产纤维素酶活的黑曲霉ZM-8菌株和优良性状啤酒酵母YB-6菌株的基础上,首先对黑曲霉ZM-8产生纤维素酶条件进行了初步探讨,然后研究了小麦秸秆固态混菌发酵生产蛋白饲料的发酵条件,提出了生物降解小麦秸秆生产蛋白饲料的工艺路线。得到了以下主要结果:1.黑曲霉ZM-8在小麦秸秆固体培养基上产纤维素酶的最优培养基配方是:小麦秸秆粉80%、麸皮20%、料水比1:2、含氮量1.4%、氮源为硫酸铵;最佳产酶条件为:培养温度为28℃、培养时间为96h、pH值为6.5、接种量为4%;在上述优化的培养基配方和培养条件下,其FPU、CMC和β-gluase酶活分别为6.57U/g、22.38 U/g和21.74U/g,分别是未优化前的3.02倍、2.2倍、2.3倍。2.黑曲霉ZM-8和啤酒酵母YB-6在小麦秸秆培养基上混菌固体发酵生产蛋白饲料的最优发酵工艺流程为:起始接种4%黑曲霉ZM-8,发酵24h后按接种量10%接入酵母菌YB-6液体菌种共生发酵48h。在该工艺流程下,纤维素和半纤维素的含量分别由发酵前的46.72%和32.51%降至32.06%和23.05%,其利用率分别达到了31.38%和28.51%;粗蛋白含量由发酵前的2.8%增加到13.75%,增加了约11个百分点,而且较黑曲霉单菌种发酵提高了约5个百分点。更多还原

【Abstract】 Biological degradation of wheat straw to produce protein fodder have been studied in this paper. studied in this paper. The purpose of the research is to broaden feedstuff source and raise its quality by biologically transforming and utilizing recycled resources. The ultimate objects of this work are to promote agriculture development continuously as a kind of clean industry. At first, mutant strains Aspergillus niger ZM-8 with high activity of cellulase and Saccharomyces cerevisiae YB-6 with strong growth ability of producing protein fodder were screened from their parent strains of A. niger by treatment of space conditions, and then the conditions for production cellulase of Aspergillus niger ZM-8 was discussed and the conditions of mix-strains wheat stalk solid fermentation to produce protein fodder was explored ,and the wheat stalk solid fermentation technology was suggested. All of these may be summarized as follows:1. Optimal constitution and conditions of wheat stalk solid fermentation to produce cellulase were studied. The results suggested that: the optimum fermentation medium contained 80% wheat stalk powder, 20% wheat bran, a solid: liquid of 1:2, 1.4%nitrogenous amount, nitrogen source was (NH4)2SO4, , and the optimum condition was at the initial pH6.5, 4% inoculum ,28℃,for 96h. Under the optimized medium and fermentation condition, the activities of FPU、CMC andβ-gluase respectively reached 6.75U/g,22.38U/g,21.74U/g.It is increased respectively by 3.0 times,2.2 times,2.3 times than unoptimized .2. The mix-strain wheat stalk solid fermentation of ZM-8 strain and YB-6 strain had been studied, and a best kind of mix-strains ferment system had been optimized out. It showed that the ZM-8 was 4% inoculated first, and the YB-6 was 10% inoculated after three days of the ferment to proceed the mix-strain solid ferment for 48h.Under the best process condition, the cellulose and hemicellulose’s content of the solid ferment product had respectively fallen from 42.67% and 32.51% to 32.06% and 23.05%, the degradation rate is 31.38% and 28.51% repectively. The gross protein content is 13.75%.,it is increased by 11 percentage points compared to protein content of wheat stalk, it is increased by 5 percentage points compared to the product that fermented only by the ZM-8 strain .更多还原