瑞士乳杆菌ND01(L.helveticus ND01)发酵乳中ACE抑制活性和γ-氨基丁酸的研究

从81株分离自新疆地区传统酸马奶中的乳杆菌中筛选到瑞士乳杆菌(L. helveticus)ND01.以该菌发酵1l%脱脂乳,测定其不同发酵时间的ACE抑制活性、游离氨基氮、γ-氨基丁酸(GABA)、pH值、OD值和滴定酸度.测定结果表明:37℃发酵24 h,发酵乳的ACE抑制活性最大值为67.18%;发酵至30h,γ-氨基丁酸的最大含量为165.11 mg/L;该菌株在pH 3.50条件下生长特性良好,具有较强的蛋白分解能力,为开发降血压乳制品提供可行性.     

益生菌Lactobacillus casei Zhang发酵特性的评价

以L.acidophilus NCFM,L.rhamnosus GG,L.casei Shirota和Bifidobacterium animalis Bb12为参照,对益生菌L.casei Zhang的发酵特性进行了研究.结果表明:发酵结束时,添加L.casei Zhang的发酵乳具有较高的pH值和较低的滴定酸度.4℃贮藏28 d后,L.casei Shirota和Bifidobacterium animalis Bb12的蛋白水解能力下降,而L.asei Zhang,L addophilusNCFM和L.rhamnosus GG蛋白水解能力不断上升.尽管Lcasei Zhang在脱脂乳中的发酵速度低于对照益生菌.但贮藏期内其活菌数缓慢上升并于贮藏结束时达到最高.L.casei Zhang完全具备益生菌所应有的发酵特性,因此其适合应用于发酵乳的开发.     

益生菌Lactobacillus plantarum4在豆乳中发酵特性的评价

以大豆为原料,利用益生菌Lactobacillus plantarum4发酵豆乳,通过测定豆乳在发酵及贮藏期间酸度、蛋白水解能力、活菌数、脱水收缩性等指标,对L.plantarum 4的发酵特性及贮藏稳定性进行研究,同时比较不同处理方法对大豆抗营养因子(脂肪氧化酶和胰蛋白酶抑制剂)的抑制作用。结果显示,L.plantarum4在豆乳中生长良好,发酵结束时,滴定酸度为68.91°T,活菌数可达到2.33×108 CFU/mL,蛋白水解能力和持水力都显著增加,感官品质较佳;低温贮藏时各指标均无明显变化,贮藏稳定性明显优于室温贮藏;同时得出热磨法是抑制大豆抗营养因子的最佳方法。研究表明L.plantarum4具备益生菌所应有的发酵特性,为其进一步应用于实际生产提供了理论依据。     

发酵乳中ACE抑制肽生成的外部因素条件的研究

探讨了促进发酵乳中ACE抑制肽生成的外部因素条件。研究结果表明,菌株发酵凝乳(pH4.7～5.0)后,产生肽量迅速积累,ACE抑制活性大幅度增强,产生的肽量与ACE抑制活性具有正相关性。添加乳清蛋白和酪蛋白可提高发酵乳中的肽含量,添加酪蛋白组更为突出;添加乳清蛋白组肽粉ACE抑制活性减弱,而添加酪蛋白组肽粉ACE抑制活性增强。与发酵温度42℃相比,37℃发酵条件下有利于发酵乳ACE抑制肽生成;与4℃冷藏处理相比,37℃条件下保温培养对提高ACE抑制活性和肽含量更为显著(P<0.01),实验结果为发酵法生产ACE抑制肽提供了可靠的技术依据。     

Lactobacillus helveticus 9的酪蛋白水解作用研究

基于酪蛋白水解度和多肽含量数据,研究了两株瑞士乳杆菌(L.helveticus 9和L.helveticus 6)与酪蛋白共培养后的蛋白水解效果,菌株L helveticus 9蛋白水解活性显著高于菌株L.helveticus 6.在不同发酵时间下,菌株L.helveticus 9对酪蛋白的水解作用随时问延长而逐渐递增,培养48h时酪蛋白的水解度可达17.3%,多肽含量达到0.62mg/ml:SDS-PAGE分析和Sephadex G-25层析鉴定表明,酪蛋白水解产物多肽含量随培养时间延长而增加.显然,具有较高蛋白水解活力的菌株L.helveticus 9可以用于从酪蛋白中来制备潜在的生物活性肽.     

具有ACE抑制活性乳酸菌的特性研究

选择了3株Lactobacillus helveticus(H—1，H—2，LH)和Lactobacillus casei(C，LC)为实验对象，分别制作发酵乳，并测定其蛋白水解活性、生长特性及ACE抑制活性(ACEI)。结果表明，发酵乳中脯氨酸及含有脯氨酸的多肽越多，其ACE抑制活性越强；而且具有较大滴定酸度的菌种很可能具有较高的ACEI活性。经筛选，H—1的A—CEI活性最高。该菌经30℃培养18h后具有最大约ACE抑制活性。     

益生菌Lactobacillus casei Zhang与商业益生菌对胃肠转运耐受性及发酵特性的比较

比较益生菌干酪乳杆菌Zhang(L.casei Zhang)与商业化益生菌嗜酸乳杆菌NCFM(NCFM)、鼠李糖乳杆菌GG(LGG)、干酪乳杆菌Shirota(kS)、动物双歧杆菌Bb12(Bb12)对人工胃肠液的耐受性及发酵特性.将各菌置于人工消化液及含3.0g/L牛胆盐的MRS培养基中,37℃培养,分别于3h和8h时测定人工胃液和肠液中各菌株的存活率,同时每小时测定MRS培养基的浊度,以延迟时间评价各菌株对胆盐的耐受性.对由各菌株制得的发酵乳在发酵及贮藏期间酸度与活菌数的变化进行了测定,结果表明,在pH 2.5的人工胃液消化3 h后,干酪乳杆菌Zhang存活率低于NCFM(p<0.05),高于其它3株对照菌(p<0.05);在pH 3.0和pH 4.0的人工胃液消化3 h后,干酪乳杆菌Zhang的存活率与4株对照菌无显著差异(p>0.05);在pH 8.0的人工肠液消化8h后,干酪乳杆菌Zhang的存活率高于Bb12(p<0.05),低于NCFM(P<0.05),与其它2株对照菌元差异(p>0.05).干酪乳杆菌Zhang对3.0g/L牛胆盐的耐受性与LcS差异不显著(p>0.05),而高于其它3株对照菌(p<0.05).脱脂乳37℃发酵24 h后,接种干酪乳杆菌Zhang的样品的酸度低于4株对照菌.4℃贮藏28 d内,各益生菌在发酵乳中继续生长,其中干酪乳杆菌Zhang发酵乳的pH值变化(降低0.55)显著高于4株对照菌(p<0.05);贮藏28 d后干酪乳杆菌Zhang活菌数为1.0×109 cfu/g,显著高于4株对照菌(p<0.05),说明干酪乳杆菌Zhang具有良好的胃肠转运耐受性和极佳的贮藏稳定性.     

发酵乳中ACE抑制肽的超滤工艺研究

本实验采用超滤法分离发酵乳中的ACE抑制肽,研究了超滤工艺的主要技术参数。结果表明:截留分子量为6000Da的超滤膜,在压力0.10MPa,温度25℃条件下,能得到具有较高ACE抑制活性的超滤液。     

益生菌Lactobacillus casei Zhang对酸奶风味、质地及感官特性的影响

将益生菌Lactobacillus casei Zhang(Lb. casei Zhang)以1.0×107g-1的添加量与商业酸奶发酵荆YC-X11共同接种进行发酵乳制备.发酵结束(pH=4.5)于4℃冷藏24 h后,分别测定发酵乳样品的酸度、黏度、脱水收缩性、挥发性风味物质、L.delbrueckii subsp.Bulgaricus、S.thermophilus和Lb.casei Zhang活菌数及对其进行感官鉴评.结果表明.Lb.casei Zhang对发酵乳样品的酸度、黏度、脱水收缩性、S.ther-mophilus活菌数无影响(P>0.05),可促进L.delbrueckii subsp.Bulgaricus生长(P<0.05),并使酸奶样品中挥发性风味物质总的质量分数提高17.1%.从而总体上提高发酵乳的感官品质.同时Lb.casei Zhang在发酵乳中具有良好的稳定性.因而益生菌Lb.casei Zhang与商业酸奶发酵剂YC-X11复配进行发酵乳生产具有极大的可行性.     

益生菌发酵剂发酵特性研究

选择干酪乳杆菌(Lactobacillu casei,Lc),嗜酸乳杆菌(Lactobacillus acdophilus,La),保加利亚乳杆菌(Lactobacillus bulgaricus,Lb)三种益生菌作为发酵肉发酵剂,对其发酵特性进行研究。结果表明:三种菌均有较强的耐亚硝酸盐、食盐能力,能够耐受150 mg/kg亚硝酸盐和6%食盐。所选菌种无蛋白和脂肪分解能力,能够有效降低pH,抑制致病菌的生长,适合发酵肉制品的生产。     

瑞士乳杆菌和嗜酸乳杆菌的益生免疫特性的研究

以瑞士乳杆菌KLDS 1.8701和嗜酸乳杆菌KLDS AD1、KLDS AD2为研究对象,详细研究了它们对体外模拟人工胃肠道的耐受性,并评估了三株乳杆菌对小鼠脾淋巴细胞增殖活性的影响,初步探讨了三株乳杆菌的免疫活性。结果表明,三株乳杆菌对人工胃液、人工肠液、胆汁盐环境具有很好的耐受性,瑞士乳杆菌KLDS 1.8701和嗜酸乳杆菌KLDS AD1较强于嗜酸乳杆菌KLDS AD2。乳杆菌对脾淋巴细胞增殖活性的作用表现出明显的量效关系,活菌数为107CFU/mL时,对脾淋巴细胞活性影响大小为KLDS AD1>KLDS 1.8701>KLDS AD2;KLDS 1.8701对脾淋巴细胞的增殖具有很好的促进作用,只有当KLDS AD1的活菌数达到107CFU/mL时才具有促进作用,而KLDS AD2没有促进作用。      

瑞士乳杆菌的益生功能及应用研究进展

瑞士乳杆菌具有强大的蛋白水解能力和诸多的益生活性,是当前益生菌研究的热点。本文对瑞士乳杆菌发酵牛乳产生的水解肽的益生活性及相关的蛋白水解系统,瑞士乳杆菌产生的胞外多糖益生活性和瑞士乳杆菌自身的益生活性进行了综述,并总结了瑞士乳杆菌在奶酪发酵中研究进展和新型应用的探索研究。诸多的研究表明,瑞士乳杆菌是一种具有广阔应用前景的益生菌。      

Angiotensin I‐converting enzyme inhibitory peptides in skim milk fermented with Lactobacillus helveticus 130B4 from camel milk in Inner Mongolia,China

BACKGROUND: Angiotensin I‐converting enzyme (ACE) is a dipeptidyl carboxypeptidase associated with the regulation of blood pressure. ACE inhibition results in a lowering of blood pressure. Lactic acid bacteria are known to produce ACE inhibitors during fermentation. Fermented camel milk is the main traditionally fermented dairy food for desert nomads. The beneficial effects of fermented camel milk, which include the prevention of such diseases and conditions as gastroenteritis, tuberculosis and hypertension, have been demonstrated experimentally. RESULTS: ACE inhibitory activity was observed in fermented milk containing Lactobacillus helveticus 130B4, a strain isolated from traditionally fermented camel milk. The peptide that inhibited ACE was purified from the fermented milk by reverse‐phase high‐performance liquid chromatography. The amino acid sequence of the peptide was identified as Ala‐Ile‐Pro‐Pro‐Lys‐Lys‐Asn‐Gln‐Asp (IC₅₀ = 19.9 µmol L^?1). The same Ala‐Ile‐Pro‐Pro‐Lys‐Lys‐Asn‐Gln‐Asp sequence was found in κ‐casein (κ‐CN) f107–115 from milk. The inhibitory activity of this nonapeptide (κ‐CN f107–115) was almost preserved even after successive digestion with pepsin, trypsin and chymotrypsin. Furthermore, the inhibitory activity of the purified peptide was completely preserved after heat treatment at 100 °C for 20 min. CONCLUSION: The fermented milk prepared with Lactobacillus helveticus 130B4 contained an ACE inhibitory peptide, κ‐CN 107–115. This fermented milk was expected to have anti‐hypertensive effect after ingestion because the peptide was stable to digestive protease and heat treatment in vitro. Copyright © 2008 Society of Chemical Industry     

瑞士乳杆菌发酵乳中多肽的分离对小鼠体外淋巴细胞增殖的影响

目的:分离瑞士乳杆菌发酵乳中多肽片段,并对分离片段的的免疫调节作用进行研究。方法:利用瑞士乳杆菌LH0906发酵牛乳获得多肽样品,采用离心、超滤的方法对所得多肽进行粗提,利用凝胶层析色谱和反相层析色谱进一步分离发酵乳中的多肽,使用Folin-Lowry法测定发酵后样品中多肽含量,采用3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐(MTT)比色法检测发酵乳中的多肽对小鼠脾脏淋巴细胞体外增殖的影响。结果:牛乳发酵液其对小鼠脾脏淋巴细胞增殖效果显著高于未发酵牛乳,并经过凝胶层析色谱和反相层析色谱分离发酵乳得到的峰S12-A对小鼠脾脏淋巴细胞体外增殖效果十分显著(P<0.01),峰S12-C对小鼠脾脏淋巴细胞体外增殖效果显著(P<0.05)。结论:牛乳经瑞士乳杆菌LH0906发酵后,分离得到的多肽片段对小鼠脾脏淋巴细胞体外增殖具有显著的增强作用。     

热激修饰对瑞士乳杆菌细胞性质的影响

根据瑞士乳杆菌生理特性,优化了其最佳生长条件:接种量2%,温度40℃,初始pH值7.1,培养时间12 h。在此条件下培养,菌液浓度可达108~109mL-1。探讨了瑞士乳杆菌特性与热激温度、时间的相关性。结果表明,低于67℃或时间少于15 s,对抑制细胞产酸无明显影响;高于69℃或时间超过20 s,胞内酶残留率不足20%,优化出热激条件为温度67~69℃,时间15~20 s。     

瑞士乳杆菌冷冻干燥保护剂的研究

本实验采用单因素试验、正交试验及均匀试验对瑞士乳杆菌在冷冻干燥过程中的保护剂进行了研究,确定了复合保护剂的组成及用量。结果表明添加保护剂后,瑞士乳杆菌的冻干存活率都有不同程度的提高,复合保护剂效果明显优于单一保护剂,以10.4%海藻糖+4.0%谷氨酸钠+11.2%脱脂乳组合的效果为最佳,冻干存活率高达86.7%。     

Effects of nitrates and nitrites on Lactobacillus helveticus and Lactobacillus casei dairy cultures

 The aim of this work was to observe the effects of nitrites and nitrates on the titratable acidity of milk after addition of Lactobacillus helveticus (TX 121) and L. casei (CAD 154) dairy cultures and on the levels of nitrate and nitrite. After adding L. helveticus and nitrites the increasing concentrations of the latter brought about a marked decrease in titratable acidity. In milk containing 100 mg·kg^–1 nitrite the resulting concentration was 39.33 mg·kg^–1 NaNO₂. Nitrates caused a less obvious decrease in titratable acidity, giving 13.27 g·l^–1 lactic acid. In milk containing 100 mg·kg^–1 NaNO₃ the resulting concentration was 24.99 mg·kg^–1 NaNO₃. Experiments with L. casei and a nitrite additive revealed a decrease in titratable acidity to 8.89 g·l^–1 lactic acid. After incubation, nitrite levels were reduced from 100 mg·kg^–1 NaNO₂ to 37.81 mg·kg^–1 NaNO₂. Nitrates were also stated to inhibit the titratable acidity of the sample, which decreased to 11.42 g·l^–1 lactic acid. Nitrates were reduced to 46.99 mg·kg^–1 NaNO₃. The present study shows that nitrites, more than nitrates decrease the titratable acidity of milk after addition of L. helveticus and L. casei dairy cultures. A reduction of nitrates and nitrites in milk samples by Lactobacillus was also found. The results of this study can be used in the dairy industry in the production of several types of hard cheese as well as fermented milk products that use L. helveticus and L. casei dairy cultures. Received: 31 March 1999 / Revised version: 6 September 1999     

瑞士乳杆菌发酵牛乳产生抗ACE活性条件的优化

本实验探讨了发酵条件对瑞士乳杆菌发酵牛乳产生抗ACE活性的影响。在单因素试验的基础上,进行正交试验,得出能产生较高抗ACE活性的最佳工艺条件是:发酵温度为37℃,发酵时间为12h,无脂乳固形物浓度12%(W/V)。     

瑞士乳杆菌对小鼠肠道黏膜和肠组织中细胞因子影响的研究

了解服用益生菌小鼠肠道黏膜和组织中细胞因子的变化情况,对阐明其对小鼠肠道黏膜免疫的影响具有重要的价值。本实验将60 只小鼠随机分成4 组：日食对照组、生理盐水对照组、瑞士乳杆菌灌喂组和大肠杆菌对照组,连续灌喂15d,采集小鼠小肠利用ELISA 法测得各组小鼠肠道黏膜和肠道组织中细胞因子的含量,并作分析。研究结果证实,与对照组相比,瑞士乳杆菌灌胃组小鼠肠黏膜和组织中4 种细胞因子明显升高,且存在显著性差异(P ＜ 0.05)：白介素-2IL-2 在3d 前达到最大值、白介素-4(IL-4)在5d 达到最高点、白介素-6(IL-6)在5d 达到顶峰、干扰素- γ(IFN- γ)在3d 前达到最大值;与对照组相比,瑞士乳杆菌灌胃组小鼠Th1 型和Th2 型T 细胞的不存在显著性差异(P ＞ 0.05),肠道免疫功能未出现异常,而大肠杆菌灌胃组Th1 型和Th2 型T 细胞平衡被打乱,免疫功能出现异常。     

Effects of Lactobacillus helveticus TUST005 fermented milk on bone parameters in rats

The effects on bone parameters were investigated using ovariectomized rats and their control ones fed with water, skim milk, sour milk, Lactobacillus helveticus TUST005 fermented milk and whey filtrate of the L. helveticus TUST005 fermented milk for 10-week interventions, respectively. Our results indicated that the ovariectomized rats are considered a suitable model for osteoporosis. The L. helveticus TUST005 fermented milk significantly increased bone mineral density, bone mineral content, the maximal load of bone and decreased bone loss compared to sour milk, and whey filtrate of the L. helveticus TUST005 fermented milk has a higher influence on bone than the fermented milk.