【作者】 索成；

【导师】 顾青；

【作者基本信息】 浙江工商大学 ， 食品工程， 2012， 硕士

【摘要】 植物乳杆菌是一种在人体、小鼠和猪的胃肠道中都有发现的非常重要的一株乳酸杆菌。它能够广泛地利用植物性碳源发酵,且能耐受胆盐和低pH值,对潜在的肠道致病菌具有拮抗能力。实验室从婴儿粪便样品中分离得到的一株植物乳杆菌ZJ316,利用该菌的饲喂添加,研究其对仔猪的生长性能和猪肉品质的影响。实验选取150头刚断奶的仔猪(28日龄)随机分为5个处理组,对照组饲喂添加抗生素乙酰甲喹的日粮；实验组Ⅰ、Ⅱ和Ⅲ饲喂添加不同浓度的植物乳杆菌ZJ316发酵液代替抗生素的日粮；实验组Ⅳ饲喂添加抗生素乙酰甲喹和植物乳杆菌发酵液ZJ316发酵液的混合日粮。实验60天后(95日龄),收集样品和数据并进行分析研究。研究结果表明：与对照组的仔猪相比,实验组的腹泻率和死亡率显著降低,日增重和饲料转化率增加。此外,实验组的猪肉品质也得到了改善,乳酸菌发酵液处理组的滴水损失、硬度、咀嚼度、胶着性和回复力明显提高。该结果表明植物乳杆菌ZJ316对于仔猪的生长性能和猪肉品质有有益的影响,但是其作用机制还需要做更深入的研究。聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)实验结果表明植物乳杆菌发酵液处理组和抗生素处理组仔猪的肠道菌群结构非常相似,且在DGGE条带中没有发现植物乳杆菌ZJ316的条带。然而植物乳杆菌处理组仔猪肠道中的短链脂肪酸的浓度要高于对照组,小肠绒毛结构也有较明显的改善。因此,我们推测植物乳杆菌ZJ316的作用机理并不是通过定植来改变肠道菌群的结构；它可能通过自身的代谢产物促进分泌短链脂肪酸(SCFA)和抑制致病菌的生长,改善小肠绒毛结构,促进仔猪生长性能和提高猪肉品质。更多还原

【Abstract】 Lactobacillus plantarum is a plant-associated Lactobacilli but has also been found in human, mouse and porcine gastrointestinal (GI) tract. It is able to ferment a broad spectrum of plant carbohydrate, tolerant against bile salts and low pH and has antagonistic potential against potential intestinal pathogens.In this study, the effects of L. plantarum ZJ316isolated from infant fecal samples on piglets growth performance and pork quality were investigated. One hundred fifty just weaned piglets (28day older) were selected randomly and separated into five groups. Control was fed the diet with the antibiotic mequindox added; groups Ⅰ, Ⅱ and Ⅲ were fed a diet with the antibiotic removed, but with L. plantarum added; and group Ⅳ was fed a mixture of mequindox and L. plantarum. Sixty days later of initiation treatment (days95), samples and data were collected for evaluating their effects.The results showed that, compared with antibiotic-treated piglets, the diarrhea and mortality ratios significant decreased, and the daily weight gain and gain rate increased in Lactobacillus-treated piglets. Moreover, the pork quality was improved when treated with Lactobacillus. Drip loss (48h), hardness, chewiness, gumminess and restoring force were significantly improved in Lactobacillus-treated piglets. Although we found that L. plantarum exerted probiotic effects on piglet growth performance and pork quality, the mechanism(s) of action needs further study.Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) results showed that the gut bacterial communities in Lactobacillus-and antibiotic-treated piglets were very similar. DGGE-band sequencing showed that L. plantarum ZJ316was not colonized in piglet gut. However, the concentration of short-chain fatty acid (SCFA) was increased in Lactobacillus-treated fecal samples and the villus height was significantly improved by Lactobacillus treatment. Therefore, we speculated that the probiotic mechanism of L. plantarum ZJ316may not be through L., plantarum colonization and alteration of the gut bacterial community. Rather, it might be related to inhibition of the growth of opportunistic pathogens and promotion of the secretion of SCFA by its metabolites, subsequently increasing villus height, and finally promoting piglet growth perfomance and improvement in pork quality.更多还原