【作者】 蔡兴旺；

【导师】 路福平；

【作者基本信息】 天津科技大学 ， 发酵工程， 2004， 硕士

【摘要】 本论文首先分析了各种条件因素对各菌种生长的影响，包括培养基组成、培养方式、培养温度、搅拌形式、接种量等，确定了各菌种的摇瓶和在5L发酵罐的发酵工艺。通过放大试验，确定了各菌种在100L～2吨发酵罐上的发酵工艺及参数。 研究了采用真空冷冻技术，确定出各菌种的最佳干粉制剂条件。制备的发酵剂粉剂中，有效活菌数为2.0×10¹¹cfu／g，水分6.2％。 还研究了秸秆发酵剂产品中各菌种的混配比例对秸秆饲料发酵效果的影响。 本论文通过菌种比例试验，加水量试验，初始pH值试验，发酵温度试验和秸秆切碎粒度试验最终确定了最佳的秸秆饲料发酵工艺：厌氧菌／好氧菌比例3：1，秸秆最佳加水量60％～65％，初始pH值7.5～8.0，发酵温度10℃～35℃，秸秆切碎粒度1～2.5cm。 在实验室基础上初步研究了秸秆饲料的酶处理工艺。添加0.05％和0.5％生物酶的发酵饲料中L-乳酸的含量为20mg／g、95mg／g，葡萄糖含量为40mg／g，发酵后粗纤维含量分别降低2％和4％：发酵后粗蛋白含量分别增加了4.8％和5.1％。表明在秸秆转化饲料时，添加饲料酶有利于乳酸积累，降低粗纤维含量和积累粗蛋白，但生产成本增加明显。 本文分析了秸秆在发酵过程中各成分的变化情况。秸秆发酵后，粗蛋白增加21.4％；粗纤维降低4.4％，相对降低14％以上：产生有机酸1.6％，pH值降到3.6。乳酸含量达有机酸总量的60％以上。 经天津市金威乳牛庄园和天津市西青区畜牧水产局对奶牛进行的饲喂试验，证明秸秆发酵剂制作的秸秆发酵饲料较对照组每头牛的日产奶量提高了约1.39～1.43公斤，乳脂率提高了0.6％～0.7％，饲喂效果良好。每头牛日增产值2.2～3.2元。更多还原

【Abstract】 The thesis focused on determination of vanillin, ferulic acid and other by-products of fermentation broth, the optimal production medium and culture conditions of Streptomyces L1936 for producing vanillin .The parameters of HPLC were determined. TLC was carried out for qualitative analysis. Spectrophotometery was used for quantitative analysis. The optimal conditions of enzyme pretreatment and extracting ferulic acid from rye bran were developed by orthogonal design theory. The optimal amount of enzymes was determined, that is . -amylase 40 /g raw material, 1398-proteinase 36 /g raw material, amyloglucosidase 400 /g raw material. The optimal technology was adopted to rye bran at 60 C for 6h with 1.0% concentration of sodium hydroxise to release ferulic acid 3.114g/L. Streptomyces L1936 could biotransformate the concentrated extract solution. The mount of vanillin in the broth was 0.174g/L. The optimization of fermentation media about the strain Streptomyces L1936 was researched. Different sorts of carbon and nitrogen resources, metal ions of inorganic salt were studied in the single factor experiments. Three ingredients (glucose, yeast extract, MgSO4 7H2O) ratio of media was optimized through Response Surface Analysis. The optimal concentrations of the factors were obtained: glucose 1.0g/L, yeast extract 1.0g/L, MgSO4 7H2O 0.2g/L.And the optimal media was as followed: glucose 1.0g/L, yeast extract 1.0g/L, MgSO4-7H2O 0.2g/L, Na2HPO4 4g, KH2PO4 1g, NaCl 0.2g, CaCl2-2H2O 0.05g, H2O 1000mL. The cultivation conditions of the strain Streptomyces L1936 was study and the optimal conditions were as followed: the inoculation size 6%, the fermentation temperature 37 C, a 500mL flask containing 50mL medium, the speed was 190r/min. The addition conditions of ferulic acid were studied. It was preferable that ferulic acid was added when the strain was in the period of stabilization. Fed-batch culture was adopted to relieve the toxic of ferulic acid to microorganism. The concentration of vanillin 7.246g/L was produced in flask and 10.51g/L vanillin was obtained in stirred tank fermentor.更多还原