关于乳酸菌的英文文献及翻译

2.4. Chemical and microbial analyses Analysis of DM and CP concentration in the experimental diets, excreta and probiotic products was done according to AOAC (1990) methods (930.05 and 976.05, respectively). The GE was measured by using the bomb calorimeter (model 1261, Parr Instrument Co., Moline, IL), and chromium concentration was determined with an automated spectrophotometer (Jasco V-650, Jasco Corp., Tokyo, Japan) according to the procedure of Fenton and Fenton (1979). The microbiological assay of faecal samples (d 14 and 28) and intestinal digesta (d 28) was conducted by culturing in different media for the determination of total anaerobic bacteria (Tryptic soy agar), Bifidobacterium spp. (MRS agar), Lactobacillus spp. (MRS agar+0.02% NaN3+0.05% L-cystine hydrochloride monohydrate), Clostridium spp. (TSC agar) and coliforms (violet red bile agar). The microbiological assay of probiotic products was also carried out by culturing technique. The L. acidophilus was enumerated using MRS agar+0.02% NaN3+0.05% L-cystine hydrochloride monohydrate, B. Subtilis by using plate count agar, S. cerevisiae and A. oryzae by potato dextrose agar. The anaerobic conditions during the assay of anaerobic were created by using gas pack anaerobic system (BBL, No. 260678; Difco, Detroit, MI). The tryptic soy agar (No. 236950), MRS agar (No. 288130), violet red bile agar (No. 216695), plate count agar (No. 247940), and potato dextrose agar (No. 213400) used were purchased from Difco Laboratories (Detroit,MI), and TSC agar (CM0589) was purchased from Oxoid (Hampshire, UK). The pH of probiotic products was determined by pH meter (Basic pH Meter PB-11, Sartorius, Germany). 2.5. Small intestine morphology Three cross-sections for each intestinal sample were prepared after staining with azure A and eosin using standard paraffin embedding procedures. A total of 10 intact, welloriented crypt-villus units were selected in triplicate for each intestinal cross-section as described previously (Jin et al., 2008). Villus height was measured from the tip of the villi to the villus crypt junction, and crypt depth was defined as the depth of the invagination between adjacent villi. All morphological measurements (villus height and crypt depth) were made in 10- m increments by using an image processing and analysis system (Optimus software version 6.5, Media Cybergenetics, North Reading, MA). 2.6. Statistical analyses All the data obtained in the current study were analyzed in accordance with a rand omized complete block design using the GLM procedure of SAS (SAS Inst. Inc., C ary, NC). In Exp. 1, one-way analysis of variance test was used and when signific ant differences (Pb0.05) were determined among treatment means, they were separ ated by using Duncans multiple range tests. In Exp. 2, the data were analyzed as a 22 factorial arrangement of treatments in randomized complete block design. Th e main effects of probiotic products (LF or SF), antibiotic (colistin or lincomycin), an d their interaction were determined by the Mixed procedures of SAS. However, as the interaction (probiotic x antibiotic) was not statistically significant (Pb0.05), it was removed from the final model. The pen was the experimental unit for all analysis i n both experiments. The bacterial concentrations were transformed (log) before stati stical analysis. 3.1. Experiment 1 3.1.1. Growth performance and apparent total tract digestibility Dietary treatments had no effect on the performance of pigs during phase I (Table 3). However, during phase II and the overall experimental period, improved (Pb0.05) ADG, ADFI and G:F were observed in pigs fed PC, LF and SF diets when compared with pigs fed NC diet. Moreover, pigs fed PC and SF diets had hi gher (Pb0.05) ADG and better G:F than pigs fed LF diet during phase II and the o verall experimentalperiod. The dietary treatments had no influence on the ATTD of DM and GE; however, pigs fed PC and SF diets had greater ATTD of CP whe n compared with pigs fed NC and LF diets (Table 4). 3.1.2. Bacterial population in faeces Dietary treatments had no effect on the faecal total anaerobes and Bifidobacterium spp. population at d 14 and 28, and Lactobacillus spp. at d 14 (Table 5). However, pigs fed PC (d 14 and 28) and SF (d 28) diets had less (Pb0.05) faecal Clostridium spp. and coliforms than pigs fed NC diet. Moreover, pigs fed SF diet had greater (Pb0.05) faecal Lactobacillus spp. populatio n (d 28) than pigs fed NC, PC and LF diets. 3.2. Experiment 2 3.2.1. Growth performance and apparent total tract digestibility During phase I, pigs fed SF diet consumed more feed than pigs fed LF diet, wher eas the ADG and ADFI were similar between pigs fed LF and SF diets (Table 6). During phase II and the overall experimental period, pigs fed SF diet showed better ADG (Pb0.01), ADFI (Pb0.01) and G:F (Pb0.05) thanpigs fed LF diet. Howev er, different antibiotics had no effect on the performance of pigs. Pigs fed SF diet had greater ATTD of DM and CP during phases I and II (Pb0.01 and 0.001, respe ctively) when compared with pigs fed LF diet (Table 7). However, different antibiotics had no effect on the ATTD of DM, CP and GE. 3.2.2. Bacterial population in intestine Pigs fed SF diet had greater (Pb0.05) Lactobacillus spp. And less Clostridium spp. (Pb0.01) and coliform (Pb0.05) population in the ileum than pigs fed LF diet (Table 8). Additionally, higher (Pb0.05) caecal Bifidobacterium spp. Population was observed in pigs fed SF diet. Antibiotics had no effect on the ileal microbial population; however, pigs fed colistin diet had less number of Bifidobacterium spp. (Pb0.05) and coliforms (Pb0.01) in the cecum, whereas, feeding of lincomycin diet resulted in reduced (Pb0.05) caecal Clostridium spp. population. 3.2.3. Small intestinal morphology The different probiotic products and antibiotics had no influence on the morphology of different segments of the small intestine, except for the greater (Pb0.05) villus height:crypt depth at the jejunum and ileum noticed in pigs fed lincomycin diet (Table 9). 4. Discussion Previous studies on probiotics lack information on the method of production used, however, the preparation of probiotics by LF method is fairly common (Patel et al., 2004). The probiotic products used in the present study differed from the previous reports in that harvested probiotic microbes were added directly to the diets. In this study, the microbial biomass grown on the CB was directly sprayed on the carrier (corn and soybean meal) to obtain LF probiotic product. In case of the SF probiotic product, corn and soybean meal was used as a substrate during fermentation and as a carrier of probiotic microbes. We have reported previously that multi-microbe probiotic product prepared by SF method was better than the probiotic product prepared by submerged liquid fermentation in improving performance, nutrient retention and reducing harmful intestinal bacteria in broilers (Shim et al., 2010). In the current study, LF and SF method was used and cornsoybean meal was used as a substrate forthe growth of potential probiotic microbes under optimum conditions. 2.4 化学和微生物分析 在试验日粮干物质和粗蛋白含量的分析中，排泄物和益生菌产品是根据 AOAC（1990）方法（分别为 930.05 和 976.05 ）分析。使用弹式量热计（model 1261, Parr Instrument Co., Moline, IL）测定总能量，根据芬顿博士（1979）的使用自动化分光光度计 确定铬浓度。 第 14 和 28 天排泄物样本和第 28 天的肠道消化物的微生物分析，将样品在不同培养基 中培养，测定总厌氧菌（胰酶解物大豆琼脂),双歧杆菌（MRS 培养基），乳杆菌种（MRS 培养基0.02% NaN3+0.05%L 胱氨酸盐酸盐水化合物），梭菌属某些种（TSC 培养基）和 大肠杆菌群（紫色红胆汁琼脂）。通过培养技术对“益生菌“ 产品进行了微生物分析。嗜酸 乳杆菌用 MRS 培养基0.02% NaN3+0.05%L 胱氨酸盐酸盐水化合物培养，枯草芽孢杆菌 通过琼脂培养基平板计数，酵母菌和米曲霉菌通过土豆葡萄糖培养基计数。通过使用厌氧 袋厌氧系统创造厌氧条件，(BBL, No. 260678; Difco, Detroit, MI)。大豆胰酶解物的琼脂 (No.236950)， MRS 琼脂培养基(No. 288130)，结晶紫中性红胆盐琼脂(No.216695)，平板计 数琼脂(No. 247940)，和马铃薯葡萄糖培养基(No. 213400)的使用是从 Difco 实验室 （(Detroit,MI)购买的，和 TSC 培养基是从 Oxoid (Hampshire, UK)购买的。益生菌产品的 pH 值由 pH 计(Basic pH Meter PB-11, Sartorius,Germany). 测定。 2.5 小肠形态学 每个肠道样本取三横截面，使用标准的石蜡包埋程序与天青 A 和曙红染色。共有 10 个 完好无损，良好的导向隐窝绒毛单位被选定为每个肠道截面，每个样品一式三份的 (Jin et al.2008)。从绒毛尖端绒毛到隐窝交界处测量绒毛高度，这个被定义为相邻绒毛内陷深度和 隐窝深度。所有形态测量（绒毛高度和隐窝深度）通过使用一个图像处理的分析系统（擎 天柱软件版本 6.5，网络媒体遗传学，北读，MA），增量为 10-m。 2.6 统计分析 在一个完全随机区组设计中对所有在当前的研究中获得的数据进行分析。在实验一中， 采用单向方差分析测试,不同处理之间显着性差异水平定为（P0.05 ），用邓肯多重比较方 法检验。在实验二中，对作为的22 因子安排的完全随机区组设计的处理数据进行分析。 益生菌产品的主要成效（LF 或 SF），抗生素（粘菌素或洁霉素），和他们的相互作用由 SAS 的混合程序计算。然而，当相互作用（益生菌 x 抗生素) 没有统计学意义时(P0.05) ， 它就要从最终的模型中剔除。在这两个实验中所有分析中都以畜舍为实验单位。在统计分 析中细菌数转化为 log 计数。 3 结果 3.1 实验1 3.1.1 生长性能和表观总消化道消化率 猪在第一阶段的饮食处理对性能没有影响（表3）。然而，在第二阶段和整个试验期间， 当与饲喂 NC 饮食的猪相比时，饲喂 PC，LF 和 SF 饮食的猪其 ADG，ADFI 和 G：F 显 著提高(P0.05) 。而且，饲喂 PC 和 SF 饮食的猪有更高的平均日增重，在第二阶段和整个 试验期间更好的 G：F 比饲喂 SF 饮食的猪有更高的平均日增重。在干物质和总能的总体 表观消化率上不同的饮食处理没有影响，然而，与饲喂 NC 和 LF 的猪相比，饲喂 PC 和 SF 的猪有更多的粗蛋白总体表观消化率（表 4）。 3.1.2 粪便中的细菌数量 不同的饮食处理对粪便中的第14天和28天的厌氧菌和双歧杆菌属和第14天的乳酸菌属没 有影响（表5）。然而，饲喂 PC（第14天和28天）和 SF（第28 天）的猪比饲喂 NC 的猪 有较少的粪便梭菌属和大肠杆菌群。而且，饲喂 SF 的猪比饲喂 N