油茶粕产枯草芽孢杆菌发酵条件优化

以油茶粕为试验原料,通过摇瓶发酵优化产枯草芽孢杆菌的工艺条件。首先通过单因素试验探讨接种量、初始pH、摇瓶装液量、摇床转速、发酵温度和时间对产枯草芽孢杆菌活菌数的影响,在此基础上选择发酵温度、摇床转速、发酵时间3个主要影响因素进行Box-Behnken设计,得到了枯草芽孢杆菌发酵最优工艺条件。结果显示:500 mL摇瓶装培养基120 mL、发酵初始pH 6.8、接种9 mL菌悬液、摇床转速180r/min、发酵温度37℃、发酵时间37 h,发酵液中活菌数可达2.04×1010CFU/mL。     

袋式固态发酵法生产饲用棉粕的初步研究

研究在益生菌与蛋白酶共同参与的袋式固态发酵体系中,棉粕的毒性因子、营养成分及微生物等的变化。结果发现,相比原棉粕,经过72 h的固态发酵与酶解,游离棉酚降低30.3%,酸溶蛋白提高了77.8%,粗蛋白无显著提高;持续检测60 d,p H降至5.5左右,枯草芽孢杆菌含量大于1.0×107cfu/g,霉菌含量小于1.0×104cfu/g。由此可见,袋式发酵工艺下棉籽蛋白的营养价值有所提高,并利于湿料储存。     

纳豆芽孢杆菌/短乳杆菌混合发酵米糠的响应面工艺优化

以稳定米糠为主要基质,豆渣为营养因子,纳豆芽孢杆菌和保加利亚乳杆、嗜热链球菌、植物乳杆茵、瑞士乳杆菌、短乳杆菌为试验菌株,运用固态发酵技术,采用响应曲面法对益生茵混合发酵米糠的固体发酵工艺进行优化分析。试验结果表明:短乳杆菌最适于与纳豆芽孢杆菌混合发酵米糠,经响应面优化后最优发酵条件如下:米糠54%、豆渣6%、水40%、接种量10%、纳豆芽孢杆菌与短乳杆菌接种比例为1:1、温度34℃,先接入纳豆芽孢杆菌发酵3 d后再接入短乳杆菌发酵2 d。发酵后米糠中纳豆激酶产生量较其他混合菌种发酵方式明显提高,其中纳豆芽孢杆菌活茵数达到6.8×10~9cfu/g短乳杆菌活茵数4.5×10~9 cfu/g。     

棉籽粕浸提及固态发酵联合工艺的优化

棉籽粕是一种高蛋白资源,但因含有棉酚,限制了棉籽粕的应用;棉籽粕中的棉籽糖也影响了动物对蛋白质的消化率。通过用溶剂浸提棉籽粕后再进行微生物发酵,不仅可以得到棉籽糖,还可以使发酵棉籽粕中棉酚含量大幅度降低。使用含1.4 mol/L柠檬酸的75%乙醇溶液浸提棉籽粕2 h,棉籽糖的浸出率达96.4%,纯化后棉籽糖纯度为91.3%;以提取棉籽糖后的棉籽粕为原料,进行植物乳杆菌、发酵乳杆菌和酿酒酵母混菌发酵制备饲料,游离棉酚含量由初始的1 274.7 mg/kg下降至118 mg/kg,脱毒率达90.74%。     

高效降解游离棉酚菌株的鉴定、安全性评价及发酵工艺研究

本实验利用芽孢杆菌发酵棉籽粕,研究对棉粕中游离棉酚降解率的影响,及对发酵前后饲料营养成分如活菌数、中性蛋白酶酶活和酸溶蛋白等的影响,并对发酵效果较好的菌株进行菌株鉴定、安全性分析及发酵工艺探索。研究发现:可高效降解棉籽粕中游离棉酚含量及改善营养品质的芽孢杆菌为BLCC1-0039,游离棉酚的测定方法确定为高效液相色谱法;菌株形态观察和生理生化鉴定并结合其16S rDNA序列,初步确定其为枯草芽孢杆菌(Bacillus subtilis);枯草芽孢杆菌杆菌BLCC1-0039的体内安全性评价,发现未对实验小鼠造成形态和活动异常,也未观察到脏器器官病变,初步确定了枯草芽孢杆菌杆菌BLCC1-0039的体内安全性;枯草芽孢杆菌BLCC1-0039发酵棉籽粕提高发酵料的酸溶蛋白含量和中性蛋白酶活性并有效降低游离棉酚含量:发酵48 h时,发酵棉籽粕酸溶蛋白为26.96%,中性蛋白酶活性为3897 U/g,游离棉酚降解率为97.81%。     

降解油茶粕发酵生产芽孢杆菌培养基条件优化

以降解油茶粕为原料,液态发酵生产枯草芽孢杆菌。经单因素实验、Plackett-Burman实验、最陡爬坡实验确定培养基组成因素的响应值及中心点,通过正交实验优化生产枯草芽孢杆菌的培养基条件。试验结果显示:优化的培养基条件是:降解油茶粕13g,可溶性淀粉1g,尿素1.5g,磷酸氢二钠0.05g,七水硫酸镁0.015g,牛肉膏0.2g,七水硫酸亚铁0.03g,酵母膏0.5g,蒸馏水100mL,自然pH。于121℃灭菌30min后接种5mL菌悬液,37℃150r/min摇床培养24h,得到含108个/mL的枯草芽孢杆菌液态发酵液。     

设施蔬菜生防用枯草芽孢杆菌M6发酵条件的优化研究

研究了设施蔬菜生防用枯草芽孢杆菌M6的发酵工艺,通过单因素试验和正交试验确定了M6的发酵培养基及条件.结果表明,枯草芽孢杆菌M6的的最优化工艺条件:玉米淀粉10g/L、大豆蛋白粉8g/L、NaCl 5g/L、K2HPO40.6g/L、培养基初始pH值7.0、培养温度35℃、接种量8％、摇床转速180r/min、培养时间42h.在此条件下发酵液活菌数达到95.8×108cfu/mL,芽孢形成率达到92％以上.此发酵条件比优化前枯草芽孢杆菌M6活菌数(85× 108cfu/mL)提高了12.7％.     

保加利亚乳杆菌冻干菌种的研究

对酸奶发酵菌种之一--保加利亚乳杆菌的增菌培养基进行了筛选,得到了高活菌数的保加利亚乳杆菌增菌培养基,并进行冷冻升华干燥得到保加利亚乳杆菌的冻干菌种。结果表明:在添加有10%麦芽汁、10%番茄汁、0.05%CaCO3、1.0%乳糖的MRS基础培养基中培养保加利亚乳杆菌18h后活菌数可达到3.96×1011cfu/g。其冻干菌种的活菌数为2.53×1011cfu/g。     

微生物固态发酵和酶解工艺处理棉粕的研究

研究了微生物和蛋白酶共同作用下棉粕中毒性因子和营养成分的变化。在枯草芽孢杆菌GJ00141、酿酒酵母GJ00079和中性蛋白酶等参与的固态发酵和酶解体系中,检测棉粕中游离棉酚、粗蛋白质、酸溶蛋白质、粗纤维、氨基酸组成、益生菌活菌数等指标。结果发现,相比原棉粕,60 h的固态发酵与酶解后,棉粕中游离棉酚含量降低40%以上,酸溶蛋白质提高了108.7%,粗纤维降低约12.7%,枯草芽孢杆菌和酿酒酵母活菌数分别为7.75、7.00 lg(CFU/g),粗蛋白质、氨基酸总量基本没有变化。由此可见,经过发酵和酶解后棉粕的营养价值和饲料品质有所提高。     

鼠李糖乳杆菌及枯草芽孢杆菌发酵对饲料品质的影响

该研究通过测定发酵饲料pH值、活菌数、乳酸含量及中性蛋白酶活性,筛选出适宜基础饲料发酵的鼠李糖乳杆菌（Lactobacillus rhamnosus）BLCC2-0038和枯草芽孢杆菌（Bacillus subtilis）BLCC1-0281,并对筛选出的鼠李糖乳杆菌和枯草芽孢杆菌进行单菌及混菌发酵方式进行了研究。结果表明,BLCC2-0038单独发酵72 h时pH值降至3.73,活菌数达到7.05×109 CFU/g,乳酸含量为48.67 mg/g;BLCC1-0281单独发酵72 h时,活菌数达到2.28×1010 CFU/g,中性蛋白酶活性达到3 207 U/g;BLCC2-0038和BLCC1-0281混菌发酵时,以鼠李糖乳杆菌/枯草芽孢杆菌配比为3∶1,2%接种量,有氧发酵方式最优,发酵72 h时鼠李糖乳杆菌活菌数为5.35×109 CFU/g,枯草芽孢杆菌活菌数为7.80×109 CFU/g,中性蛋白酶活性为1 407.83 U/g。     

Short communication: Canola meal as a substitute for cottonseed meal in diet of midlactation Holsteins

The growing demand by humans for monounsaturated vegetable oils has provided canola meal (CM) for use in dairy diets because it possesses an excellent nitrogen profile for rumen microbes. Six midlactation cows were used in a replicated 3 × 3 Latin square design with 3 periods of 20 d each. Treatments included diets with 1) CM, 2) 50% CM + 50% cottonseed meal (CSM), and 3) CSM. Total crude protein (CP), nonprotein nitrogen, and rapidly degradable true protein (% of CP) were greater in CM than in CSM. The neutral and acid detergent fibers, slowly degradable true protein, and unavailable CP were lower in CM than in CSM. Daily feeding of 3.4 kg of CM instead of 5.6 kg of CSM enhanced milk percentage of protein and SNF, and improved total tract digestibility of dry matter and CP. Therefore, CM offers an economical substitute for CSM in midlactation diets when commercial access, cost, and quality of CSM are variable.     

Production effects of extruded soybean meal replacing canola meal in the diet of lactating dairy cows

This study investigated the effects of extruded soybean meal (ESBM) in comparison with canola meal (CM) fed on an equivalent crude protein (CP) basis on lactational performance and ruminal fermentation of dairy cows. Following a 2-wk covariate period, 48 Holstein cows averaging (±SD): 146 ± 46 d in milk (DIM) and 43 ± 7 kg/d milk yield (MY) were assigned 1 of 2 treatment diets in a randomized complete block design experiment, which included a 2-wk period for dietary treatment adaptation before experimental data were collected. Following the adaptation period, samples and experimental data were collected for a total of 7 wk. Cows were blocked based on parity, DIM, and MY. Treatment diets contained 15.8% CM (containing 41.2% CP) or 13.2% ESBM (with 48.7% CP) of total mixed ration dry matter (DM), with similar inclusion of other feed ingredients. The CM diet was supplemented with canola oil, whereas the ESBM diet was supplemented with soybean hulls to achieve similar ether extract and neutral detergent fiber contents between the diets. Urea and rumen-protected Met and Lys were added to both diets to meet or exceed cow recommendations. Whole-ruminal digesta samples were collected from 10 (5 per treatment) ruminally cannulated cows. Eight cannulated cows were removed during the last week of the experiment to participate in another study. Treatment did not affect DM intake and MY or energy-corrected MY of the cows. Energy-corrected MY, apart from experimental wk 5, was similar between treatments. Apart from experimental wk 3 and 7, milk fat concentration and yield were greater for cows fed ESBM compared with CM. In multiparous cows only, milk true protein yield was greater for cows fed CM compared with ESBM. Ruminal concentration of total volatile fatty acids and the molar proportion of acetate were greater for ESBM, and propionate and valerate were greater in cows fed CM. Acetate to propionate ratio was greater for cows fed ESBM versus CM diet. Compared with the CM diet, the ESBM diet increased plasma concentrations of Ile, Leu, and Phe but not the sum of essential AA. Apparent total-tract digestibility of acid detergent fiber was greater in cows fed ESBM relative to CM. In this experiment, CM and ESBM included on an equal CP basis in the diet of dairy cows, resulted in similar DM intake, MY, and feed efficiency.     

Cassava leaf meal as a replacement for coconut oil meal in pig diet

Two feeding trials were conducted to evaluate cassava leaf meal (CLM) as a replacement for coconut oil meal (COM) in tropical pig diets. In each trial, 36 pigs (initial weight, 14.5 kg) were limit fed diets containing 0, 133, 267 and 400 g kg^?1 CLM substituted for equal amounts (w/w) of COM in a 179 g kg^?1 protein basal diet. An extra-period Latin-square changeover design with 2-week periods was used. Average daily gain and feed efficiency were improved when diets containing 133 g kg^?1 CLM were fed, which may be attributed to the higher lysine content of CLM. Daily gain and feed efficiency of pigs fed diets containing 267 g kg^?1 CLM were similar to those on the basal diet. Poor performance of pigs fed the 400 g kg^?1 CLM diets may be explained by the low energy content and the presence of anti-nutritional factors, such as cyanide and tannin, in CLM. Two balance trials were conducted using 16 barrows (castrated male pigs, initial weight, 37.2 kg). Apparent digestibility coefficients for dry matter, energy, protein, cell contents, cell wall and hemicellulose were depressed, whereas those for ash and lignin were improved as CLM was substituted for COM. The data indicate that cassava leaf protein is utilised efficiently, although other nutrients in CLM are not as digestible as those in COM.     

Effect of combinations of fish meal and feather meal on milk fatty acid content and nitrogen utilization in dairy cows

The effect of supplemental fishmeal in combination with feathermeal at two different proportions in the diet on milk docosahexaenoic acid (DHA) content was investigated. Recently, benefits to human health have been attributed to the consumption of this fatty acid, which is normally present in marine lipids. Six Holstein cows past peak lactation were used in a Latin square design with a 2 x 3 factorial arrangement of treatments. Fish- and feathermeals were prepared as pellets at 4:1 and 1:4 combinations and offered at 3.75, 11.75, and 27% of the diet. The supplements were top-dressed onto a basal diet based on corn silage that was progressively replaced by supplement. Nitrogen balance measures were made during the experiment because of the wide range in crude protein content of experimental diets. Milk protein content increased with level of supplementation in the diet reflecting the protein quality of the supplements used. There was overall higher milk DHA content when cows consumed the supplement containing more fishmeal than feather meal. Milk DHA content increased in a quadratic fashion, as more of either supplement was included in the diet. Apparent transfer efficiency of DHA from diet to milk declined with increasing amount of DHA in the diet. Results from this experiment suggest that transfer of docosahexaenoic acid from diet to milk may depend on diet composition and quantity present in the diet.     

菜籽饼粕中硫代葡萄糖甙测定方法的探讨

通过单因素试验、正交实验等分析方法探讨了紫外分光光度法测定菜籽粕中硫甙含量的各个因素条件,实验结果表明,方法的最佳酶解反应条件为:酶量:样品量=2:10,缓冲溶液的pH=7,温度30℃,时间2h;最佳显色反应条件为:氨水-乙醇浓度为20%,温度50℃,时间2 h;检出限范围1.4～280 μmol/g,精密度实验的变异系数为0.39%.     

枯草芽孢杆菌选育及发酵大豆粕工艺条件研究

以紫外诱变所得枯草芽孢杆菌B1–2发酵大豆粕生产大豆多肽,通过单因子及正交试验确定最佳发酵条件,结果表明:发酵培养基中含9%大豆粕、2%麸皮,利用培养24h枯草芽孢杆菌B1–2菌株作为菌种,在初始pH7.5,温度35℃~40℃,接种量8%条件下发酵64h,大豆粕水解度可从初始条件17.80%提高至21.06%,相比条件优化前水解度提高18%。     

超声水提花生粕多糖工艺的研究

采用响应面法对超声波辅助水提法提取花生粕多糖的工艺进行了研究。探讨了超声功率、提取时间、提取温度、液料比4个因素对花生粕多糖得率的影响。试验结果表明,最佳的工艺条件为超声功率70 W,提取时间24 min,提取温度71℃,液料比29∶1,在此条件下花生粕多糖得率为1.80%。     

浅谈低变性棉籽粕的制备

生产棉籽蛋白的原料棉籽粕在预处理、浸出、脱溶工段与普通的工艺相比有着特殊的要求,从而保证制得的棉籽粕在含杂、蛋白质变性程度、色泽、纤维素含量等方面符合要求。通过生产试验研究了低变性棉籽粕的制备工艺。     

花生粕酥性饼干的研制

以面粉为基料,添加一定量的花生粕制作花生粕酥性饼干。研究了花生粕、油脂、白砂糖、水分对花生粕酥性饼干品质的影响。在单因素的基础上,通过正交实验得出产品的最佳配方为:花生粕、油脂、白砂糖和水分的最佳添加量分别为32%、35%、35%和22%。     

去皮豆粕的生产与应用

在大豆浸出制油过程中,通过增加脱皮工艺,可得到高蛋白去皮豆粕.将豆粕与收集的豆皮分别粉碎后,把豆皮按需添加至去皮豆粕中,可得到不同粗蛋白(CP)含量的的等级豆粕.影响脱皮效果的因素主要有干燥温度、破碎辊间隙、吸风量、豆皮筛网规格等.高蛋白豆粕比普通豆粕具有较高的营养与使用价值,随着饲料工业的发展,我国高蛋白豆粕在饲料中所占比例将逐步增加.