不同精油的抑菌效果及协同作用研究

为研究三种精油(肉桂醛、百里香酚、香兰素)的抑菌效果及其协同作用,本试验采用牛津杯法和试管二倍稀释法测定抑菌圈的值径及最小抑菌浓度,结果表明:三种精油对大肠杆菌K88、沙门氏菌、金黄色葡萄球菌都有较强的抑菌效果,在相同浓度下,抑菌效果为肉桂醛>百里香酚>香兰素;当百里香酚与肉桂醛以4∶1复合时,对大肠杆菌K88的抑菌效果最佳;当肉桂醛与香兰素以4∶1复合时,对沙门氏菌和金黄色葡萄球菌的抑菌效果最佳。综上所述,肉桂醛和百里香酚的抑菌效果优于香兰素,百里香酚与香兰素,肉桂醛和香兰素复配时具有协同作用。     

植物精油与有机酸的抑菌效果及协同作用研究

试验研究了植物精油、有机酸对大肠杆菌、金黄色葡萄球菌和沙门氏菌的抑菌效果,并研究了植物精油与有机酸复合的协同作用,结果表明:植物精油中肉桂醛的抑菌作用优于百里香酚和香兰素,百里香酚与肉桂醛以1.3的比例复合时抑菌效果最强,有机酸中柠檬酸的抑菌作用优于山梨酸和苯甲酸,植物精油与柠檬酸复合后对大肠杆菌、金黄色葡萄球菌、沙门氏菌均具有明显抑菌作用,表明植物精油和有机酸具有协同作用。     

细菌敏感精油的筛选及与乳化剂组合的抑菌效果研究

为了筛选常见病原菌敏感的精油和乳化剂,首先采用牛津杯法测定了12种精油对产气荚膜梭菌、大肠埃希氏菌和鼠伤寒沙门氏菌的抑菌作用,然后将筛选出的5种抑菌效果较好的精油与吐温系列乳化剂分别按不同比例互作,测定对上述3种细菌的最小抑菌浓度(MIC),最后根据MIC结果,测定产气荚膜梭菌在低于精油MIC下的生长曲线以及在MIC下的菌体形态变化。结果显示,肉桂醛对产气荚膜梭菌最敏感,且10%吐温40乳化肉桂醛可显著降低对产气荚膜梭菌的MIC;生长曲线表明1/2、1/4、1/8MIC的肉桂醛对产气荚膜梭菌的生长均有明显抑制作用;扫描电镜显示肉桂醛作用后的产气荚膜梭菌形态发生明显改变。肉桂醛对产气荚膜梭菌的抑菌效果优于其他精油。试验结果为临床防治产气荚膜梭菌引发的梭菌性肠炎提供了科学依据。     

不同植物精油对畜禽呼吸道致病菌的影响

试验旨在通过对17种具有良好抑菌效果植物精油的体外抑菌试验，筛选出对引起畜禽细菌性呼吸道感染常见致病菌（大肠杆菌、沙门氏菌、乙型溶血性链球菌、金黄色葡萄球菌）有显著疗效的单一植物精油品种，再通过体外抑菌正交试验筛选出最佳的植物精油复配方案，最后通过人工攻毒建立动物感染模型，筛选出复配精油组合的最佳治疗剂量，为植物精油防治家禽细菌性呼吸道疾病奠定理论基础。结果表明：在17种植物精油中，抑菌效果最好的单一植物精油是肉桂醛和香芹酚，对大肠杆菌、沙门氏菌、金黄色葡萄球菌的最小抑菌浓度均为0.391 mg/mL，对乙型溶血性链球菌的最小抑菌浓度均为0.781 mg/mL。抑菌效果最佳的植物精油组合为2∶1的肉桂醛∶牛至油和2∶1的肉桂醛∶百里香酚，2∶1的肉桂醛∶牛至油对沙门氏菌、金黄色葡萄球菌的最小抑菌浓度均为0.195 mg/mL，对大肠杆菌、乙型溶血性链球菌的最小抑菌浓度均为0.391 mg/mL;2∶1的肉桂醛∶百里香酚对大肠杆菌、沙门氏菌、金黄色葡萄球菌的最小抑菌浓度均为0.195 mg/mL，对乙型溶血性链球菌的最小抑菌浓度为0.391 mg/mL。在2∶1的肉桂醛∶百里香酚复合植物...     

不同植物精油体外抑菌效果的研究

植物精油是一种天然绿色活性物质,具有很好的抑菌效果,其在饲料中应用具有广阔开发前景。本文采用琼脂平板孔洞法分别对不同来源的肉桂醛、香芹酚等植物精油及其混合物进行体外抑菌效果筛选和评估。结果表明,香芹酚、肉桂醛、百里香酚和丁香酚对大肠杆菌、沙门氏菌、金黄色葡萄球菌等常见动物消化道内有害菌有很好的抑菌效果,其抑菌顺序为肉桂醛>香芹酚>丁香酚>百里香酚,用棕榈油进行1:4比例稀释后,精油的抑菌效果均有不同程度的下降。由4种精油组成的复方产品对大肠杆菌等肠道有害菌有较好的抑制作用,且热稳定性好。结论:肉桂等植物精油对常见有害菌具有良好的抑菌效果,可作为天然的抑菌剂。     

体外法评估不同植物精油对需氧菌的抑菌活性

本试验采用琼脂平板法,测定肉桂醛、百里香酚、香芹酚、牛至油、丁香酚和山苍子油对产肠毒大肠杆菌、宋氏志贺氏菌、乙型溶血性链球菌的最低抑菌浓度,从中选出抑菌能力较强的精油,继续测定其对产肠毒大肠杆菌、出血性大肠杆菌、宋氏志贺氏菌、痢疾志贺氏菌、猪霍乱沙门氏菌、鼠伤寒沙门氏菌和乙型溶血性链球菌的抑菌效果,筛选出具有替抗潜力的精油并评估精油作为抑菌剂应用在饲料中的前景。本试验采用琼脂平板培养法,在固态培养基中添加不同浓度的肉桂醛、百里香酚、香芹酚、牛至油、丁香酚和山苍子油,分别接种产肠毒大肠杆菌、宋氏志贺氏菌、乙型溶血性链球菌,测定其最低抑菌浓度,初步筛选出抑菌作用较强的精油,利用同样的方法,继续测定其对产肠毒大肠杆菌、出血性大肠杆菌、宋氏志贺氏菌、痢疾志贺氏菌、猪霍乱沙门氏菌、鼠伤寒沙门氏菌和乙型溶血性链球菌的最低抑菌浓度,最终筛选出抑菌能力较强的精油。结果表明:①通过初筛,发现肉桂醛、百里香酚、香芹酚、牛至油和丁香酚的抑菌效果较好,选择该五种精油进行复筛;②复筛结果表明,精油对供试菌株的抑菌能力由强到弱为百里香酚>肉桂醛>香芹酚>牛至油>丁香酚,其最低抑菌浓度分别为为0.02%～0.07%、0.02%～0.08%、0.03%～0.07%、0.04%～0.09%、0.07%～0.18%;③百里香酚、肉桂醛、香芹酚、牛至油作为饲料添加剂具有极好的潜力。     

15种植物精油添加剂热稳定性和体外抑菌作用研究

肉桂醛、香芹酚、丁香酚、百里香酚等植物精油活性物质具有广谱抑菌作用,在兽用抗菌药物减量化使用试点行动推动下,以植物精油为核心的添加剂产品越来越多。本研究旨在比较市售的15种猪、禽用植物精油添加剂的热稳定性,并探究它们对畜禽生产中常见病原菌的体外抑菌作用,以期为植物精油添加剂的合理使用提供参考。分别以多重耐药的猪源沙门菌、大肠杆菌和链球菌以及禽源沙门菌和大肠杆菌为研究对象,以大肠杆菌ATCC25922为质控菌,采用微量肉汤法体外测定肉桂醛、香芹酚、丁香酚、百里香酚和各精油添加剂的最小抑菌浓度(MIC)。通过棋盘稀释法比较肉桂醛、香芹酚、丁香酚和百里香酚不同复配组合对猪源大肠杆菌的抑菌效果。将每种添加剂等量分为对照组和热处理组,分别经乙醚抽提和气相色谱仪分析后,对每种添加剂中肉桂醛、香芹酚、丁香酚和百里香酚及其总量进行测定比较。结果显示:6株供试菌株对肉桂醛、香芹酚、丁香酚和百里香酚均表现出高度敏感性(MIC值0.25～2 mg/mL);当香芹酚:百里香酚和丁香酚?百里香酚复配比例为2∶1时表现出协同作用(FICI=0.5);植物精油添加剂EG2对6株供试菌无明显抑菌作用,其余14种产品的MIC值为1～32 mg/mL。此外,15种添加剂含肉桂醛、香芹酚、丁香酚和百里香酚的总量范围在2.64～691.40 mg/g;15种产品热处理前后精油总量变化范围在0.2%～14.11%。综上所述,受试精油添加剂产品普遍热稳定性较好,并具有一定的抑菌作用,且抑菌效果与产品肉桂醛、香芹酚、丁香酚、百里香酚和精油总量存在一定的正相关;EG7、EG3、ES2、ES1、EAP2和EP1这6种产品的体外抑菌效果明显,有潜力用于预防和治疗多重耐药菌引起的猪禽疾病。     

植物精油及其复合物的抑菌效果研究

试验旨在比较植物精油分别与有机酸、丁酸类物质复合后对大肠杆菌和金黄色葡萄球菌的抑菌效果。试验将植物精油分别与丁酸钠、丁酸甘油酯、山梨酸、苯甲酸和柠檬酸按照不同比例复合,采用牛津杯法测定抑菌圈直径。结果表明:复合植物精油、有机酸均具有抑菌效果,而丁酸钠和低浓度丁酸甘油酯不具有抑菌效果。植物精油与有机酸或丁酸衍生物复合后对大肠杆菌、金黄色葡萄球菌均具有明显抑菌作用。综上可得,植物精油与苯甲酸或柠檬酸复合具有协同作用。     

由中链脂肪酸与植物精油为主要成分组成的复合型酸化剂抑菌性能的研究

为探究替代抗生素促生长剂(Antibiotics growth promoter,AGP)的高效复合型酸化剂,选取中链脂肪酸和4种植物精油主要成分-肉桂醛、百里香酚、丁香酚、香芹酚,以大肠杆菌、沙门氏菌和金黄色葡萄球菌等3种菌为指示菌,利用正交优化实验,得到抑菌性能最优的复合型酸化剂配方,并初步探讨其抑菌性能。结果表明,由植物精油主要成分与中链脂肪酸组成的复合酸化剂的最优配比为:辛酸、香芹酚、癸酸、肉桂醛、丁香酚、己酸=2∶1∶1∶5∶2∶2;其对温度具有一定的敏感性,但其抑菌时间长,指示菌不易回长,抑菌性能高且在模拟胃肠液环境中均具有良好的抑菌作用。该复合型酸化剂成分安全、抑菌高效、具备诱食性,可以作为高效型复合酸化剂开发利用。     

黑胡椒、快乐鼠尾草与生姜精油的化学成分及其对产气荚膜梭菌的抑制活性

用水蒸气蒸馏法提取了黑胡椒、快乐鼠尾草与生姜精油,采用GC-MS技术分析了各精油的主要化学成分,并用纸片扩散法和最小抑菌浓度法测定4种植物精油对产气荚膜梭菌的体外抑菌作用。结果表明,3种精油的主要成分中主要是酚类、萜类化合物及萜类化合物的含氧衍生物且各精油均有较强的抑菌作用。     

植物提取物及其复合物对鸡源致病菌的体外抑菌作用

本研究选取10种具有较强抑菌作用的植物提取物,研究其对鸡源致病菌(鸡大肠杆菌和鸡沙门氏菌)的体外抑菌作用,并分别筛选出对2种致病菌有较强抑菌作用的3种植物提取物,将其按不同比例复配,以获得抑菌效果更强的复合植物提取物。本研究分为2个试验。试验1:共设11个组,分别为百里香精油、牛至精油、肉桂精油、大蒜油、黄芩黄酮、竹叶黄酮、黄芪多糖、小檗碱、苦参碱和绿原酸和金霉素组(阳性对照组),每组6个重复,采用牛津杯法测定植物提取物对大肠杆菌和沙门氏菌的抑菌作用。试验2:根据试验1的结果,选取对大肠杆菌抑菌效果较好的肉桂精油、苦参碱和绿原酸3种植物提取物,分别按照不同浓度比例进行两两和3种植物提取物复配,用牛津杯法测定复合物对大肠杆菌的抑菌作用,同时分别设相应浓度的3种单一植物提取物为对照组,共20个组,每组6个重复;选取对沙门氏菌抑菌效果较好的竹叶黄酮、黄芩黄酮和肉桂精油3种植物提取物,用牛津杯法测定不同浓度比例的复合物和相应浓度的单一植物提取物(对照组)对沙门氏菌的抑菌作用,共17个组,每组6个重复;根据以上结果,研究了竹叶黄酮和肉桂精油按不同浓度比例复配对沙门氏菌的抑菌作用,以筛选最佳复配比例,共15个组,每组6个重复。结果表明:5种植物提取物对大肠杆菌有抑菌作用,其抑菌作用从大到小依次为肉桂精油、苦参碱、绿原酸、百里香精油、牛至精油;8种植物提取物对沙门氏菌有抑菌作用,其抑菌作用从大到小依次为竹叶黄酮、黄芩黄酮、肉桂精油、苦参碱、绿原酸、牛至精油、百里香精油、大蒜油。与肉桂精油对照组相比,肉桂精油、苦参碱和绿原酸两两或3种植物提取物复配不能显著增强对大肠杆菌的抑菌作用(P0.05);竹叶黄酮和肉桂精油复配可显著增强对沙门氏菌的抑菌作用(P0.05),且在浓度比例为25∶150(1∶6)时抑菌作用达到最大。由此可见,10种植物提取物中,对大肠杆菌抑菌效果较好的3种植物提取物为肉桂精油、苦参碱和绿原酸,但这3种植物提取物复合物的抑菌作用并不大于单一肉桂精油;对沙门氏菌抑菌效果较好的3种植物提取物为竹叶黄酮、黄芩黄酮和肉桂精油,竹叶黄酮和肉桂精油复配增强了抑菌效果,且复配比例为1∶6时对沙门氏菌的抑菌作用最大。     

柠檬不同部位精油的成分分析及抑菌活性

采用水蒸气蒸馏法提取北京柠檬叶片、枝干和果皮的精油,并进行GC-MS分析,共鉴定出38种成分,其中叶片23种,枝干21种,果皮29种。3份精油主要挥发油成分均为D-柠檬烯,相对含量分别为52.85%、53.03%和51.23%;共有成分14种,特异性成分分别有4种、3种和14种。通过对3种食源性细菌的抑菌活性的测定,3份柠檬精油均有一定程度的抑菌作用,其中,叶片精油对大肠埃希氏菌和金黄色葡萄球菌抑菌效果最佳,且抑菌圈直径最大;果皮精油对伤寒沙门氏菌的抑菌效果最佳,抑菌圈最大。研究结果表明,柠檬不同部位精油活性成分含量差异较大,在对其开发利用时,可考虑各自优势,合理利用柠檬的叶片、枝干和果皮,为柠檬资源合理化和精细化的开发利用提供一定的科学依据。     

丁酸梭菌对致病菌和有益菌的体外作用效果研究

试验研究了丁酸梭菌在体外对致病菌的抑制作用和对有益菌的增殖作用。将丁酸梭菌分别与大肠杆菌、沙门氏菌、产气荚膜梭菌、乳酸杆菌、双歧杆菌按不同的比例混合后进行培养,并与菌种单独培养进行比较。结果表明:培养36～48 h,联合培养组大肠杆菌、沙门氏菌、产气荚膜梭菌菌数均显著低于单独培养组;菌数比例为(1～100)∶1至100∶1时,丁酸梭菌对沙门氏菌均有较强的抑菌作用;菌数比例为100∶1时,丁酸梭菌对大肠杆菌和产气荚膜梭菌抑菌作用较强;菌数比例为10∶1时,丁酸梭菌对乳酸杆菌和双歧杆菌的增殖效果最好。联合培养8 h后,菌数比例为10∶1时,丁酸梭菌对双歧杆菌有显著的增殖效果。     

Population of Salmonella serovar typhimurium in the cecum of gnotobiotic chickens with Escherichia coli and intestinal bacteria.

To test the interaction between various species of bacteria and Salmonella serovar typhimurium (S. typhimurium), the population of S. typhimurium was measured in the cecum of gnotobiotic chickens in the presence of Escherichia coli (E. coli) and one of the four intestinal bacteria; Lactobacillus acidophilus. Clostridium perfringens, Bifidobacterium thermophilum and Bacteroides vulgatus. Competitive exclusion of S. typhimurium by di-flora chicken was not demonstrated. But the population of S. typhimurium was temporarily suppressed in di-flora chickens with E. coli and L. acidophilus. In penta-flora chickens with E. coli and these four intestinal bacteria, the population of S. typhimurium was suppressed for only 2 days. In normalized chickens, the population of S. typhimurium was markedly suppressed.     

Use of rosemary, oregano, and a commercial blend of essential oils in broiler chickens: in vitro antimicrobial activities and effects on growth performance

The present study was conducted to characterize the in vitro antimicrobial activities of 3 essential oils [oregano, rosemary, and a commercial blend of essential oils (BEO)] against pathogenic and nonpathogenic bacteria and to evaluate their effects on broiler chicken performances. The chemical composition of the essential oils was determined using the gas chromatography interfaced with a mass spectroscopy. The disc diffusion method, the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC) were applied for the determination of antimicrobial activities of essential oils. In vivo study, a total of seven hundred fifty 1-d-old male broiler chickens were assigned to 6 dietary treatment groups: basal diet (control; CON), CON + 44 mg of avilamycin/kg (A), CON + 100 mg of rosemary essential oil/kg (ROS), CON + 100 mg of oregano essential oil/kg (OR), CON + 50 mg of rosemary and 50 mg of oregano essential oils/kg (RO), and CON + 1,000 mg of BEO/kg (essential oil mixture, EOM). The essential oils isolated from rosemary and oregano were characterized by their greater content of 1,8-cineole (49.99%) and carvacrol (69.55%), respectively. The BEO was mainly represented by the aldehyde (cinnamaldehyde) and the monoterpene (1,8-cineole) chemical groups. The results of the disc diffusion method indicated that the rosemary essential oil had antibacterial activity (P ≤ 0.05) against only 3 pathogenic bacteria, Escherichia coli (8 mm), Salmonella indiana (11 mm), and Listeria innocua (9 mm). The essential oil of oregano had antimicrobial activities (P ≤ 0.05) on the same bacteria as rosemary but also on Staphylococcus aureus (22 mm) and Bacillus subtilis (12 mm). Oregano essential oil had greater (P ≤ 0.05) antimicrobial activities against pathogenic bacteria than rosemary essential oil but they had no synergism between them. The BEO showed an increased antimicrobial activity (P ≤ 0.05) against all studied bacteria (pathogenic and nonpathogenic bacteria) except for Lactobacillus rhamnosus. The supplementation of the basal diet with avilamycin or essential oils improved (P ≤ 0.05) broiler chicken BW, BW gain, and G:F compared with the CON diet. There were no differences in growth performances among birds fed A, ROS, OR, RO, or EOM diets. In general, essential oils contained in rosemary, oregano, and BEO can substitute for growth promoter antibiotics. Although the 3 essential oils had different antimicrobial activities, they exhibited the same efficiency in broiler chickens.     

Use of active substances of plant origin in chicken diets based on maize and locally grown cereals

1. A total of 336 Hubbard Hi-Y broiler hybrids were fed from d 1-41 on diets based on maize or wheat and barley which were supplemented (or not) with 100 mg/kg plant extract consisting of capsaicin, cinnamaldehyde and carvacrol. 2. Body weight was not enhanced, but feed conversion improved by 4.2% on the maize diet and 2.0% on the wheat and barley diet. 3. Plant extract addition enhanced the breast muscle proportion of empty body weight by 1.2% in comparison to control birds. 4. The apparent ileal digestibility of nutrients (crude protein, fibre and amino acids) was not significantly better in birds fed on supplemented diets than in the control group. 5. Reduction of E. coli, Clostridium perfringens and fungi and increase of Lactobacillus spp. were observed in the 41-d-old chickens from the supplemented groups. 6. An increase in the lipase activity in pancreas and intestine wall was found in older birds fed on the plant extract supplemented diets.     

鱼腥草煎剂和颗粒剂有效成分及其体外抗菌活性比较

为探讨传统中药煎剂与免煎颗粒剂有效成分和药效上的差异,利用回流提取浓缩机组制备了鱼腥草原药浓缩液,同时利用喷雾干燥机将部分原药浓缩液制备成干粉;并对鱼腥草两种剂型中槲皮素的含量进行测定和二者体外抑菌效果的观察。通过试验发现,鱼腥草原药浓缩液与喷雾干燥粉中的槲皮素含量无统计学上的差异,而在体外抑菌试验中,鱼腥草原药浓缩液对大肠埃希菌、沙门菌和金黄色葡萄球菌的最小抑菌浓度均低于喷雾干燥粉。     

肉桂醛体外抑制奶牛乳房炎主要致病菌的研究

研究天然化合物肉桂醛对奶牛乳房炎主要致病菌——大肠杆菌、金黄色葡萄球菌和链球菌的抑菌效果。采用试管二倍稀释法测得肉桂醛对奶牛乳房炎主要致病菌金黄色葡萄球菌和标准金黄色葡萄球菌的体外最小抑菌浓度(MIC)分别为3.2 mmol/L和1.6 mmol/L;链球菌1.6 mmol/L;大肠杆菌和标准大肠杆菌6.4 mmol/L和3.2 mmol/L,且能完全抑制这三种菌的生长。肉桂醛的最小杀菌浓度(MBC)金黄色葡萄球菌和标准金黄色葡萄球菌分别为25.6 mmol/L和12.8 mmol/L;链球菌12.8 mmol/L;大肠杆菌和标准大肠杆菌25.6 mmol/L和12.8 mmol/L;在7 h内能有效杀灭这三种菌,肉桂醛对奶牛乳房炎主要致病菌有抑菌和杀菌能力,是一种潜在的奶牛乳房炎的临床治疗药物。     

Effects of dietary essential oil components on growth performance,digestive enzymes and lipid metabolism in female broiler chickens

1. The present experiment was conducted to describe the effects of thymol, cinnamaldehyde and a commercial preparation of essential oil components (CRINA Poultry), in female broilers. Feed and water were provided for ad libitum consumption. 2. Feed intake, weight gain and feed:gain ratio were not different among the treatments. Water intake was significantly lowered by cinnamaldehyde. Relative liver weight (g/100 g of body weight) was highest in birds given thymol, but this was seen only at the age of 21 d and not at 40 d. Patterns of digestive enzymes in pancreatic tissue were similar for the 4 treatments. 3. Amylase activity in intestinal digesta was highest in chickens given CRINA Poultry for 21 d, but the effect had disappeared after 40 d. Ileal digestibility coefficients for starch and protein were high and identical for all treatments. 4. Fatty acid composition of diet was reflected in that of adipose tissue. Plasma lipid concentrations were not changed by any dietary treatment. 5. Thus, the present results show no effect of essential oil constituents on growth performance in female broiler chickens, but it cannot be excluded that positive effects would have been observed under less hygienic environmental conditions or when using a less digestible diet.     

预防犊牛腹泻复合微生态制剂3株菌种的配比优化

试验旨在研究预防犊牛腹泻复合微生态制剂3株菌种的配比优化。通过研究嗜酸乳杆菌、布氏酵母菌、枯草芽孢杆菌不同浓度人工胃液、人工肠液、牛胆盐的耐受性及其对大肠杆菌、沙门氏菌、金黄色葡萄球菌的抑菌性,确定其生物学特性;以大肠杆菌K99为指示菌,研究3种益生菌不同配比对大肠杆菌K99的抑菌效果,以确定其最佳组合。结果表明:(1)3种益生菌在不同pH人工胃培养条件下都具有较好的耐受性,其中嗜酸乳杆菌、芽孢杆菌在pH为5时,存活率达到了118.75%、142.24%,布氏酵母菌对不同pH均表现成活率达到了100%以上。(2)3种益生菌在人工胃液中9 h存活率较高,与0 h的OD600相比,布氏酵母菌、枯草芽孢杆菌、嗜酸乳杆菌存活率分别为108.7%、129.73%、96.37%。(3)在含有不同浓度的牛胆盐培养基中,布氏酵母菌、嗜酸乳杆菌、枯草芽孢杆菌存活率较对照组的存活率最高为60.49%、85.1%、47.42%。(4)3株益生菌按照不同配比在培养12 h后,试验组第2、4、8组较对照组相比差异显著(P<0.05);培养24 h后,试验组第3、4、5、6较对照组差异显著(P<0.05),组间差异不显著(P>0.05);第8个处理组在培养12 h后对大肠杆菌K99的抑菌效果较好。综合分析,3株益生菌对人工胃液、人工肠液、牛胆盐具有较好的耐受性,并具对大肠杆菌K99、沙门氏菌、金黄色葡萄球菌等致病菌均有一定的抑菌特性。嗜酸乳杆菌、枯草芽孢杆菌、布氏酵母菌最佳的优化配比为3:3:1。