昂立植物乳杆菌及其抑菌物质的特性研究

该文研究了昂立植物乳杆菌(LP-Onlly)菌体及其代谢产物的抑菌性能,并对其代谢产物中的抑菌物质进行了部分理化特性的考察,发现LP-Onlly菌体对部分肠道有害菌有抑制作用,代谢产物中的抑菌物质对常见的肠道致病菌和食品腐败微生物具有广谱抑菌作用,对嗜酸乳杆菌及双歧杆菌等益生菌无抑制作用.该物质具有热稳定性,但抑菌活性受pH值的影响较大.     

双歧杆菌粘附对肠上皮癌细胞酶的影响

目的 研究双歧杆菌粘附对肠道细胞生理功能和能理代谢的影响。方法 以婴儿型双直菌ＤＮＭ９２２７菌株粘附大肠癌ＣＣＬ－１８７细胞为实验模型。结果 婴儿以歧杆菌ＤＭ９２２７菌株在适宜的条件下与培养的大肠癌ＣＣＬ－１８７细胞共同培养１ｈ后,ＣＣＬ０１８６细胞的碱性磷酸酶以及琥珀脱氢酶的以反应均有所增强。结论 双歧杆菌对被粘附的大肠癌细胞的生理功能和能量代谢具有正向影响。     

植物乳杆菌粘附性与其表面特征关系的探究

本文通过16s rDNA鉴定获得4株植物乳杆菌,并以HT29细胞为体外黏附筛选模型,进一步探讨了这些菌株粘附能力与表面疏水性、自聚共聚能力等表型特征的相关性。结果表明,植物乳杆菌AR326菌株对HT29细胞的粘附性最强,并显示高度的自聚性(25%)和共聚性(25%),但其表面疏水性偏低(15%);通过相关性分析发现,植物乳杆菌的自聚性和共聚性与HT29细胞粘附性呈显著相关性(r=1.0和0.8,p0.05),但表面疏水性、自凝聚性和共聚性两两之间并无显著相关性(p0.05)。本研究结果为建立快速筛选高粘附性植物乳杆菌的方法及其菌株在体内定植和分布研究提供一定参考依据。     

乳杆菌抑制金黄色葡萄球菌对HeLa细胞的粘附

对弯曲乳杆菌Lactobacillus crispatus T79-3和T90-1、詹氏乳杆菌Lactobacillus jensenii T118-3和T231-1四株乳杆菌对金黄色葡萄球菌生长的抑制效果以及抑菌成分进行了分析,比较乳杆菌排除、竞争、置换3种不同作用方式对金黄色葡萄球菌粘附HeLa细胞的抑制作用。结果表明4株乳杆菌皆能抑制金黄色葡萄球菌的生长及其粘附HeLa细胞的能力,分析发现4株乳杆菌发挥抑制作用的主要成分是有机酸,同时比较分析乳杆菌3种不同作用方式发现它们对金黄色葡萄球菌粘附HeLa细胞的抑制效果不同,其中,排除作用方式效果最好。另外,乳杆菌对金黄色葡萄球菌粘附HeLa细胞的抑制作用具有浓度依赖性,随着乳杆菌浓度增大,抑制作用增强并逐渐达到饱和。4株乳杆菌中,T79-3粘附能力最强,对金黄色葡萄球菌的抑制作用最强,排除作用方式抑制金黄色葡萄球菌粘附HeLa细胞作用效果较好,提示乳杆菌T79-3有可能作为益生菌防治妇女泌尿生殖道感染。     

荧光标记法初探植物乳杆菌ST-Ⅲ对Caco-2细胞的粘附机理

利用荧光探针CFDA-SE标记植物乳杆菌ST-Ⅲ,测定其对Caco-2细胞粘附能力的变化,提取相关物质,探讨其粘附机理。化学和酶处理ST-Ⅲ菌悬液发现,经胃蛋白酶、胰蛋白酶、氯化锂、苯酚、盐酸胍和热处理能显著降低ST-Ⅲ的粘附性,表明表面蛋白或脂磷壁酸(Lipoteichoic acid)可能参与了ST-Ⅲ对Caco-2细胞的粘附。粘附抑制试验和可逆性结合实验证实表面蛋白而非脂磷壁酸参与了ST-Ⅲ对Caco-2细胞的粘附。结果表明ST-Ⅲ的表面蛋白粗提物可能含有粘附素类的S-层蛋白(S-layer protein),经SDS-PAGE电泳分析,此粗提物主要成分的分子量分别为72.7、34.1和24.3kD。     

昂立植物乳杆菌发酵及其稳定性能的研究

研究昂立植物乳杆菌(LP-Onlly)的发酵特性、耐药性及遗传稳定性.结果表明LP-Onlly发酵培养条件为:37 ℃培养16～18 h发酵结束,pH可达4.4左右;LP-Onlly对研究的33种抗生素敏感、7种耐受;LP-Onlly连续传代15代后,基因组DNA指纹图谱及代谢产物HPLC指纹图谱与原代保持一致.     

昂立植物乳杆菌耐酸、耐胆盐性能及相关表型、基因型分析

目的从益生菌功能性评价出发,探讨昂立植物乳杆菌(LP-Onlly)的耐酸、耐胆盐性能及其相关的表型和基因型信息.结果 LP-Onlly在耐酸、耐胆盐性能方面,优于其他实验室保存菌株,在pH 3、37 ℃培养3 h后,LP-Onlly活菌存活率达95%以上.在1.0%胆盐的MRS培养液中生长24 h后,LP-Onlly活菌存活率达95%以上.经表型及分子鉴定,LP-Onlly为植物乳杆菌,其16S rDNA序列保存于GenBank, 登录号为AY 590777,与实验室保存的其他植物乳杆菌的基因DNA指纹图谱相似率达71%.     

乳杆菌DM8909对阴道上皮细胞粘附现象的初步研究

本文分析了乳杆菌DM8909菌株及自阴道分离的肠杆菌、葡萄球菌、白色念珠菌对阴道上皮细胞的粘附能力。结果显示,在正常阴道酸性条件(pH3.5—4.5)下,DM8909菌株对阴道上皮细胞的粘附能力明显高于肠杆菌(P<0.01)、葡萄球菌(P<0.01)、白色念珠菌(P<0.01);随pH增加,DM8909粘附能力降低,肠杆菌、葡萄球菌、白色念珠菌粘附能力增强;DM8909菌株能较强地抑制肠杆菌、葡萄球菌对阴道上皮细胞的粘附。本文提示,乳杆菌粘附形成的空间占位是防止其他菌对阴道组织附着的一个重要的保护性机制。     

荧光标记法测定植物乳杆菌ST-Ⅲ对肠道致病菌的粘附抑制及其相关机制的研究

目的研究植物乳杆菌ST-Ⅲ对大肠埃希菌和沙门菌与Caco-2细胞粘附的抑制作用,并初探其机制。方法采用CFDA-SE荧光标记的方法测定加入ST-Ⅲ前后对致病菌对Caco-2细胞粘附能力的变化,通过化学和酶处理ST-Ⅲ细胞壁表面成分、提取相关物质,研究ST-Ⅲ对致病菌粘附的抑制机制。结果 ST-Ⅲ对2种致病菌都具有明显的抑制粘附的能力,其在相同情况下对大肠埃希菌粘附的抑制效果好于对沙门菌的效果(P0.05)。化学和酶处理表明ST-Ⅲ的表面蛋白或者磷壁酸可能参与了对致病菌粘附的抑制过程,提取后发现表面蛋白对大肠埃希菌的粘附表现出极强的抑制效果(P0.01),而对沙门菌的粘附没有抑制作用(P0.05);磷壁酸对2种致病菌均不具备抑制粘附的作用。结论 ST-Ⅲ对大肠埃希菌与Caco-2细胞粘附的抑制作用主要是通过竞争性抑制,而对沙门菌粘附的抑制作用主要是通过空间位阻形成的。     

昂立植物乳杆菌对腹腔感染大鼠肠道微生态的影响

目的探讨经肠道补充昂立植物乳杆菌(LP-Onlly)对腹腔感染大鼠肠道微生态的影响.方法大鼠经盲肠结扎穿孔法及颈静脉空肠置管制成腹腔感染模型后,分别给予肠外营养(PN组)和PN 昂立植物乳杆菌(LP-Onlly组)持续5 d,第6天处死,取盲肠内粪便进行肠菌群培养计数及细菌种群DNA指纹图谱分析.结果 LP-Onlly组大鼠肠道内的乳杆菌和双歧杆菌数量较单纯PN组的大鼠为多,而肠道内的潜在致病菌产气荚膜梭菌数量较单纯PN组的大鼠少,DNA指纹图谱也显示LP-Onlly组大鼠优势菌群的基因条带和正常大鼠具有较高的一致性,而PN组则差异有显著性.结论 LP-Onlly能纠正腹腔感染大鼠PN时的肠道菌群紊乱, 调理肠道微生态平衡.     

Effects of environmental stresses on the physiological characteristics,adhesion ability and pathogen adhesion inhibition of Lactobacillus plantarum KLDS 1.0328

Changes in the physiological state and adhesion of probiotics under stresses affect their interaction with the host. The effects of osmotic (3% NaCl, 6% NaCl, and 3% NaCl + 3% KCl), acid (pH 5.0), and alkali (pH 8.0) stress on the physiological characteristics, adhesion ability and pathogen adhesion inhibition of Lactobacillus plantarum KLDS 1.0328 were investigated. The results showed that 6% NaCl resulted in lower acid production, growth and antimicrobial activity of cells compared to control and 3% NaCl treatment. Reduced surface hydrophobicity, aggregation ability, adhesion ability and pathogen adhesion inhibition were observed when L. plantarum KLDS 1.0328 was exposed to 6% NaCl. These changes were weakened when NaCl was partially replaced by KCl. Exposure to stresses other than alkali stress significantly increased the ratio of unsaturated fatty acid to saturated fatty acid in the cell membrane. The autoaggregation and adhesion ability of cells were increased under pH 5.0 treatment. The results demonstrated that the abilities of cells to adhere and inhibit pathogen adhesion were significantly positively correlated with the ability to coaggregate with pathogens. This study provides a basis for our understanding of the response of L. plantarum to stresses and the related molecular mechanisms.     

Ensiling whole-crop wheat and corn in large containers with Lactobacillus plantarum and Lactobacillus buchneri

The effect of applying Lactobacillus buchneri, alone or in combination with Lactobacillus plantarum, at ensiling, on the aerobic stability of wheat and corn silages was studied in 50-l plastic containers. Treatments comprised control (no additives), L. plantarum, L. buchneri and a combination of L. plantarum+L. buchneri. After 3 months of storage, the wheat silages treated with L. buchneri had higher acetic acid contents than the control or L. plantarum-treated silages, and were free of mold, whereas the top layers of the control or L. plantarum-treated silages were moldy. In an aerobic stability test the L. buchneri-treated silages were stable, whereas those treated with L. plantarum deteriorated. In the corn silages the effects of L. buchneri were not as clear and the top layer was moldy in all silages. However, L. buchneri also improved the aerobic stability of the corn silage, as indicated by lower yeast numbers, less CO₂ production and stable pH. It is concluded that L. buchneri has a potential as a silage additive that protects the silage upon aerobic exposure. The 50-l plastic containers can serve as an appropriate model to test silage additives before conducting full-scale farm experiments. Journal of Industrial Microbiology & Biotechnology (2002) 28, 7–11 DOI: 10.1038/sj/jim/7000207 Received 17 April 2001/ Accepted in revised form 25 August 2001     

Lactobacillus plantarum AS1 binds to cultured human intestinal cell line HT-29 and inhibits cell attachment by enterovirulent bacterium Vibrio parahaemolyticus

Aim: Lactobacillus plantarum AS1 was incubated with HT‐29 adenocarcinoma cell line to assess its adhesion potency and examined for its inhibitory effect on the cell attachment by an enterovirulent bacterium Vibrio parahaemolyticus. Methods and Results: Lactobacillus plantarum AS1 attached efficiently to HT‐29 cells as revealed by scanning electron microscopy and bacterial adhesion assay. Lactobacillus plantarum AS1 significantly reduced V. parahaemolyticus attached to HT‐29 cells by competition, exclusion and displacement mode. Lactobacillus plantarum AS1 seems to adhere to human intestinal cells via mechanisms that involve different combinations of carbohydrate and protein factors on the bacteria and eukaryotic cell surface. Conclusion: Strain Lact. plantarum AS1 inhibits the cell attachment of a pathogen V. parahaemolyticus by steric hindrance mechanism. Also, antibacterial factors such as bacteriocins, lactic acid and exopolysaccharides could be involved. Significance and Impact of the Study: The ability to inhibit the adhesion of V. parahaemolyticus to intestinal cell line warrants further investigation to explore the use of probiotic strain Lact. plantarum AS1 in the management of gastroenteritis caused by V. parahaemolyticus.     

一株具有良好粘附性的植物乳杆菌的生物学特性及应用

本文研究了植物乳杆菌AR326的最适生长温度、最适接种量、生长曲线、最适初始pH、胆汁耐受性、NaCl耐受性,并进一步探究了单菌株发酵酸奶的性能。结果显示植物乳杆菌AR326生长较快,4 h进入对数期,14 h进入稳定期,最适生长温度为30℃,在初始pH 3.0~7.0范围可生长,适宜的接种量为1.5%~2.0%,耐受胆盐浓度达0.2%,耐高渗透压能力强,可在含NaCl 8%的MRS培养基中生长。发酵乳中菌落数和对照组一致,脱水收缩性优于对照组,因而可用于商业上生产功能性酸奶。     

Lactobacillus plantarum: Microfiltration experiments for the production of probiotic biomass to be used in food and nutraceutical preparations

Several studies have focused their attention on increasing the production of lactobacillus ssp. (LAB) biomass via‐fermentation, in particular exploiting novel in situ product removal bioreactors that prevent accumulation of lactic acid, and therefore growth inhibition. Lactobacillus plantarum is one of the most studied species, used in nutritional supplements and in food processing. This research aimed to obtain high cell densities of L. plantarum, through fed‐batch and microfiltration experiments. The latter achieved a 5‐fold higher biomass density compared with batch experiments. Furthermore, the L. plantarum strain, isolated from Portoguese chorizo, was characterized for its ability to survive simulated digestion in vitro and competition potential toward certain common pathogens. Finally, the possibility of exploiting dairy liquid wastes (whey) as medium components was also explored demonstrating the strain's capability of metabolizing bovine‐ovine whey. This finding might be relevant in liquid waste treatments of diary industries that are well distributed in our region. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:325–333, 2015     

两株母乳源植物乳杆菌的全基因组测序分析

【背景】母乳是一个重要的益生菌筛选库,其中植物乳杆菌是一种用途广泛、适应性强的益生菌。然而不同菌株具有不同的功能,现有的生理生化方法对其潜在益生特性研究十分有限,有必要采用高通量的方法寻找具有种群特异性的优质益生菌。【目的】结合菌株生化特征在全基因组的测序与分析的基础上对两株植物乳杆菌的潜在功能进行预测,并重点找寻与肠液耐受性及细菌素的合成相关的基因,即在基因组的结构上对菌株的表型进行探究。【方法】分离筛选出两株母乳源植物乳杆菌MP55、MP37,并利用Illumina genome analyzer对菌株的全基因组进行测序,采用Prokka软件对细菌基因组进行注释,采用Carbohydrate-active enzymes (CAZy)、Koyto encyclopedia of genes and genomes(KEGG)和Clusters of orthologous genes(COG)数据库对基因组进行功能注释;同时采用Prodigal、RNAmmer等工具对编码序列、核糖体RNA进行预测,并用CGView软件绘制菌株的基因组环形图谱。【结果】通过基因组装得到了两株植物乳杆菌的全基因组信息,植物乳杆菌MP37、MP55基因组大小分别为3 204 421 bp和3 299 180 bp;(G+C)mol%含量分别为44.36%和44.46%;分别包含3 012个和3 101个DNA编码序列,结合菌株生化特征在基因组上找到4个与肠液耐受相关的基因及一段细菌素合成相关基因簇。基因组序列原始数据和拼接结果已提交至"gcMeta"平台。【结论】通过高通量测序分析在基因组水平上揭示了植物乳杆菌MP55、MP37在肠道存活性与抑制病原菌相关的可能机理。植物乳杆菌MP55、MP37是两株潜在的益生菌候选菌株,实验结果为进一步阐明其益生菌特性的功能机制提供了遗传学基础。