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以小肽含量为指标筛选出一株用于固态发酵豆粕的枯草芽孢杆菌(BSW-2),并对工艺条件进行了优化,最后通过变性梯度凝胶电泳技术( PCR-DGGE)探讨了发酵过程中细菌群落的变化.结果表明:最佳工艺条件为接种量0.5%,料水比1∶1.2,发酵温度35℃,发酵时间36 h.在此条件下,发酵豆粕小肽含量从11.52 mg/g提高到202.20 mg/g,粗蛋白含量从47.65%提高到55.63%.PCR-DGGE结果表明,菌株BSW-2在整个发酵体系中均占有绝对优势. 相似文献
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微生物发酵法生产大豆肽工艺条件的研究 总被引:1,自引:0,他引:1
以脱脂豆粕为原料,采用地衣芽孢杆菌发酵生产大豆肽.研究菌株种龄、种子液接种量和摇床速度对多肽产量的影响,结果表明,种龄12 h,接种量5%,摇床速度180 r/min最佳.同时,对影响多肽产量的发酵温度、发酵时间及豆粕粉加水量3个主要因素用正交试验方法进行优化,正交试验结果发现,该菌株发酵产多肽的最佳条件为温度37℃,发酵时间48 h,加水量94%.优化后该菌株发酵豆粕后的多肽溶液酸性可溶氮含量达到1 384.65μg/mL,水解度DH为23.89%. 相似文献
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文章研究了3种发酵增效剂对发酵豆粕肽含量的影响。在复合菌剂接种量为0.5%,无氧发酵48 h后有氧发酵24 h条件下,以正交试验的方式对发酵增效剂在发酵豆粕基质中添加量、发酵温度、料水比进行优化。分别得到3种发酵增效剂最适宜的添加条件。发酵豆粕肽含量随3种发酵增效剂添加量增大而提高(P<0.01)。发酵增效剂Ⅰ组中,发酵温度为41℃时最佳,料水比4:6最适宜,最优条件组合发酵豆粕肽含量观测值为18.99%;发酵增效剂Ⅱ组中,发酵温度39℃或41℃时最佳,料水比3:7最适宜,优化后发酵豆粕产肽量观测值为17.57%;发酵增效剂Ⅲ组中,料水比3.5:6.5或3:7时最适宜,优化后发酵豆粕肽含量观测值为19.67%。通过抗原蛋白抽提及SDS-PAGE分析可知,在发酵基质中添加发酵增效剂可以改善豆粕中抗原蛋白降解程度。比较最适宜添加条件下3种发酵增效剂对肽含量的提高效果可知,发酵增效剂Ⅲ对发酵豆粕肽含量提高效果最佳,在39℃、3:7料水比、5kg/t添加量条件下可使发酵豆粕肽含量提高208.31%。 相似文献
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试验旨在研究乳酸菌发酵豆粕工艺参数优化及其对豆粕营养成分的影响。采用单因素试验和正交试验探究发酵时间、发酵温度、乳酸菌粉接种量、液料比对发酵豆粕中粗蛋白含量的影响,优化发酵工艺参数,比较最优工艺条件下发酵前后豆粕中各营养成分的差异。结果显示,影响发酵豆粕中粗蛋白含量的因素排序为发酵时间>乳酸菌粉接种量>发酵温度>液料比,最优工艺参数为发酵温度32℃、乳酸菌粉接种量1.5%、发酵时间72 h和液料比0.8 L/kg。在最佳工艺条件下,发酵后豆粕中粗蛋白含量达49.64%。与发酵前相比,发酵豆粕中粗蛋白含量显著高于发酵前(P<0.05),胰蛋白酶抑制因子含量降解率达97.32%(P<0.05)。研究表明,利用乳酸菌对豆粕进行固态发酵可进一步有效改善豆粕营养价值,提高豆粕利用率。 相似文献
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试验首先利用响应曲面法对豆粕固态发酵过程中影响蛋白酶产率的因素进行优化,以确定变温发酵温度转变的最佳条件。以蛋白酶活力为指标,对蛋白酶活力的二次回归模型分析采用SAS 9.1.3统计软件。通过优化,豆粕发酵时蛋白酶产生的最佳条件为发酵温度30℃、基质层厚度1.75 cm、含水量44%及发酵时间44 h,此条件发酵豆粕中蛋白酶活力可达907.94 IU/g。由此确定变温发酵在44 h后提高发酵温度至40℃,再继续发酵28 h,对比变温发酵与恒温发酵样品中蛋白含量与酸溶蛋白含量,结果表明变温发酵可以减少微生物对营养物质的消耗,但可以产生更多的低分子肽类物质,发酵72 h后其酸溶蛋白含量可达19.75%,其含量比恒温发酵提高6.45%。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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以国际标准强毒R株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离MG,并收集感染鸡所产蛋分离MG。结果表明,人工感染48小时后上、下呼吸道及肺已被全面感染,96小时气囊已被感染,120小时输卵管已能分离到MG,卵巢始终分离不到MG。人工感染鸡自144小时便能在其所产蛋中分离出MG。药物治疗能在72小时内消除感染,油乳剂苗则需24天后逐渐降低蛋内MG分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内MG,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献