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。     

对阴道炎主要致病菌有抑菌活性乳杆菌的筛选及特性

目的从实验室保藏的乳杆菌中筛选出对阴道炎主要致病菌有抑菌活性的乳杆菌,研究其生物学特性从而作为防治阴道炎的潜在益生菌株。方法采用琼脂扩散法检测乳杆菌对大肠埃希菌、金黄色葡萄球菌和阴道加德纳菌的抑菌效果。采用共培养法探究乳杆菌在不同时间对白假丝酵母生长的抑制效果。检测乳杆菌产过氧化氢和产酸能力、对低pH环境的耐受性以及对家兔阴道黏膜的刺激性。结果植物乳杆菌LP45和鼠李糖乳杆菌LR519对大肠埃希菌、金黄色葡萄球菌和阴道加德纳菌的抑菌效果最佳。经24 h共培养后,LP45和LR519对白假丝酵母的抑制率分别为95.27%和98.85%。LP45和LR519产过氧化氢量分别为11.28μg/mL和15.15μg/mL,能耐受pH 4.5酸环境。LP45和LR519复合菌在37℃培养48 h可持续产乳酸,且对家兔阴道黏膜无刺激性。结论植物乳杆菌LP45和鼠李糖乳杆菌LR519具有优良的生物学特性,可作为阴道微生态制剂的候选菌株来预防和缓解由菌群紊乱而引起的阴道炎症。     

高黏附罗伊氏乳杆菌的筛选及其益生特性评价

通过对28株不同罗伊氏乳杆菌(Lactobacillus reuteri)菌株的粘附力、细胞表面疏水性、与大肠杆菌的共聚合等指标的测定及相关性分析,成功筛选出粘附力最高的菌株R28。研究了该菌株的耐酸性和耐胆盐能力。结果表明,R28与其它菌株相比具有良好的粘附能力。该菌株的自聚集能力和疏水性分别为26.25%和75.53%。与大肠杆菌的共聚合能力可高达36.84%。细胞粘附数可达约43个细菌/每个杆菌细胞。菌株R28具有良好的耐酸性(pH=3)和耐胆盐性(0.1%),其能够很好的粘附于宿主肠道细胞发挥益生作用。罗伊氏乳杆菌R28作为一株优良的益生菌在食品和医药领域具有广阔的应用前景。     

具有拮抗无乳链球菌能力乳杆菌的筛选及抑菌特性

目的从罗非鱼(Nile tilapia)肠道中筛选出具有抑菌作用的乳杆菌,测定其对无乳链球菌(Streptococcus agalactiae)的抑菌效果,分析乳杆菌抑制无乳链球菌的有效成分,并利用分子生物学手段对筛选的乳杆菌菌种进行鉴定。方法采用双层平板法对具有抑制无乳链球菌的乳杆菌进行筛选,牛津杯法对抑菌效果进行测定,酶蛋白敏感性测定、热处理、有机酸处理等方法分析抑菌活性物质有效成分,16S rDNA分子标记对乳杆菌进行鉴定。结果从罗非鱼肠道中筛选出14株乳杆菌,其中菌株RS2对无乳链球菌具有明显的抑菌效果;不同蛋白酶种类、pH处理对乳杆菌无细胞培养液均有不同的影响,经80℃处理的乳杆菌无细胞培养液,其抑菌效果未显著改变(t=0.169 2,P=0.873 8)。此外,此株乳杆菌对猪霍乱沙门菌(Salmonella choleraesuis)、大肠埃希菌(Escherichia coli)、金黄色葡萄球菌(Staphylococcus aureus)和志贺菌(Shigella sp.)等病原菌具有良好的抑制作用。经鉴定,该乳杆菌为植物乳杆菌(Lactobacillus plantarum)。结论从罗非鱼肠道中分离得到的植物乳杆菌菌株RS2对无乳链球菌等致病菌具有一定的抑制作用,推断其抑菌有效成分为细菌素类物质。此项研究对开发抗生素替代产品,提高食品的品质具有一定价值。     

乳杆菌DM8909对金黄色葡萄球菌与阴道上皮细胞粘附影响的研究

本文对乳杆菌ＤＭ８９０９对阴道主要致病菌金黄色葡萄球菌与阴道上皮细胞的粘附影响作了补充实验。将等量ＤＭ８９０９液与金黄色葡萄球菌液同时与上皮细胞粘附进行了观察。结果表明,体外试验中,在ｐＨ７２情况下,乳杆菌与葡萄球菌同时加入时葡萄球菌粘附数量比葡萄球菌单独粘附少（Ｐ＜００１）,乳杆菌与金葡菌粘附数量相差不大（Ｐ＞００５）;乳杆菌与金葡菌先于ｐＨ４５下作用８１２ｈ,然后与上皮细胞同时孵育２小时,粘附的乳杆菌与金葡菌量比ｐＨ７２时均有减少,而金葡菌量比其单独粘附明显减少（Ｐ＜００１）,且明显少于乳杆菌（Ｐ＜００１）。说明乳杆菌能抑制葡萄球菌对阴道上皮细胞的粘附     

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。     

阴道中益生特性乳杆菌的分离与功能评价

目的分离健康女性阴道中的乳杆菌并鉴定其益生特性,为开发治疗妇科疾病的复方益生菌制剂提供新型菌株。方法采集健康女性阴道分泌物并分离筛选乳杆菌,通过16SrDNA序列分析鉴定乳杆菌分离株,并对其产酸性能、产H2O2能力、抑菌能力、产生物膜能力进行检测。结果从50名健康女性阴道内共分离出179株乳杆菌,其中卷曲乳杆菌101株、詹氏乳杆菌42株、格氏乳杆菌26株、植物乳杆菌5株、唾液乳杆菌3株以及干酪乳杆菌2株。179株乳杆菌中有146株具有产酸能力,发酵液pH值的最低的5株菌分别为卷曲乳杆菌J3、卷曲乳杆菌J8、詹氏乳杆菌J87,植物乳杆菌J75以及格氏乳杆菌J35,其pH分别为4.20、4.23、4.24、4.26及4.36;产H2O2弱阳性菌株有87株、阳性有37株、强阳性有9株,这9株菌分别为卷曲乳杆菌J3、卷曲乳杆菌J8、卷曲乳杆菌J20、詹氏乳杆菌J87,詹氏乳杆菌J90、詹氏乳杆菌J15、格氏乳杆菌J11、植物乳杆菌J75、植物乳杆菌J69以及植物乳杆菌J40;能拮抗大肠埃希菌的菌株有115株、拮抗金黄色葡萄球菌的有84株、拮抗白假丝酵母的有52株;经统计,对三者同时有拮抗作用且作用最强的只有6株,分别为卷曲乳杆菌J3、卷曲乳杆菌J50、卷曲乳杆菌J62、詹氏乳杆菌J87、詹氏乳杆菌J16和格氏乳杆菌J66;不同乳杆菌产生物膜能力数值范围在1.0~5.4,卷曲乳杆菌、詹氏乳杆菌、干酪乳杆菌的生物被膜形成能力显著高于其他三种菌(P0.05)。在全部179株菌中,卷曲乳杆菌J3和詹氏乳杆菌J87既具有强的产酸能力和产过氧化氢能力,又有较强抑菌活性,同时产生物膜能力也最强。结论卷曲乳杆菌J3和詹氏乳杆菌J87具有优良的生物学特性,有望成为用于治疗妇科疾病微生态制剂的备选菌株。     

双歧杆菌QJ405、乳杆菌QJ405在试管内对肠道致病菌抑杀效果的初步报告

目的 观察双歧杆菌ＱＪ４０５和乳杆菌ＱＪ４０５在试管内对肠道致病的抑菌和杀菌效果。方法 抑菌实验：实验组,双歧杆菌ＱＪ４０５和乳杆菌ＱＪ４０５分别与各致病菌共同培养;对照组,实验组中的细菌各自单独培养。然后观察一定间隔时间（每２ｈ或４ｈ）细菌的数量变化,并绘制生长曲线。杀菌实验：将２种菌的培养上清液定量滴在已均匀涂布定量致病菌的平板表面,然后观察滴过上清液的区域内是否有细菌生长。结果：４种肠道致病菌和２株标准菌株（ＡＴＣＣ２５２９２２,ＡＴＣＣ２５９２３）的生长明显受到抑制。乳杆菌ＱＪ４０５的代谢产物有杀菌作用。结论 双歧杆菌ＱＪ４０５和乳杆菌ＱＪ４０５具有益生菌的性质。     

乳杆菌DM8909对大肠杆菌粘附阴道上皮细胞抑制作用的研究

本文对乳杆菌ＤＭ８９０９对大肠杆菌粘附阴道上皮细胞的抑制作用进行了研究。采用３Ｈ－ＴｄＲ将由阴道分离的大肠杆菌进行同位素标记。刮取健康妇女阴道上皮细胞与其进行体外粘附试验作为对照组,试验组先行阴道上皮细胞与乳杆菌ＤＭ８９０９粘附后,再加入标记的大肠杆菌。结果显示：试验组阴道上皮细胞粘附的大肠杆菌的ｃｐｍ值明显低于对照组（Ｐ＜０．０５）,说明乳杆菌ＤＭ８９０９能有效地抑制大肠杆菌对阴道上皮细胞的粘附。     

卷曲乳杆菌对三种结肠上皮细胞的粘附性

目的研究卷曲乳杆菌对3种结肠上皮细胞(SW480细胞、SW620细胞、LOVO细胞)的粘附性。方法将处于对数生长期的卷曲乳杆菌A7分别与SW480细胞、SW620细胞、LOVO细胞进行体外粘附试验,革兰染色后显微镜观察卷曲乳杆菌A7对3种结肠上皮细胞的粘附结果并计数。结果卷曲乳杆菌A7对3种结肠上皮细胞的粘附均具有显著性,其中对于SW480细胞和LOVO细胞的粘附性明显高于SW620细胞。结论卷曲乳杆菌A7对SW480细胞、SW620细胞、LOVO细胞均具有较强的粘附性,提示该菌株有望成为肠道益生菌的新成员。     

Bacteriocin properties of Lactobacillus fermenti, Lactobacillus brevis and Lactobacillus buchneri

Four bacteriocins of L. fermenti, 3 bacteriocins of L. brevis and 1 bacteriocin of L. buchneri were studied with respect to morphology of the inhibition growth zones of the indicator strains, capacity for diffusion through cellophane, sensitivity to high temperature, bacterial proteases, trypsin, chymotrypsin, pepsin, papain, nucleases and lysozyme. According to the differences in their properties the bacteriocins were classified as belonging to 8 types, including 4 types of L. fermenti bacteriocins and 3 types of L. brevis bacteriocins.     

Differentiation of Lactobacillus casei, Lactobacillus paracasei and Lactobacillus rhamnosus by polymerase chain reaction

Lactobacillus casei, Lact. paracasei and Lact. rhamnosus form a closely related taxonomic group within the heterofermentative lactobacilli. These three species are difficult to differentiate using traditional fermentation profiles. We have developed polymerase chain reaction primers which are specific for each of these species based on differences in the V1 region of the 16S rRNA gene. Sixty-three Lactobacillus isolates from cheese were identified using these primers. The 12 Lact. rhamnosus and 51 Lact. paracasei identified in this way were also differentiated using a randomly amplified polymorphic DNA (RAPD) primer.     

Protoplast fusion between Lactobacillus casei and Lactobacillus acidophilus

Summary From the fusion between Lactobacillus casei and Lactobacillus acidophilus, 8 fusants were selected: Four were able to ferment maltose, lactose, galactose and mannose, but two had greater abilities of acid production than parents. Increased values of up to 7.6–8 % in -galactosidase activity were obtained from two when compared to that of L. acidophilus, whereas another 2 had activities of 800 and 548 nmol/mg protein/min comparable to that of L casei giving a value of 400 nmol/mg protein/min in phospho--galactosidase activity.     

Lactose metabolism in Lactobacillus curvatus and Lactobacillus sake

Abstract The lactose metabolism was investigated in five strains of Lactobacillus curvatus and 14 strains of L. sake isolated from meat or meat-derived products. Strains with the ability to ferment lactose were found in both species. They exhibited either phospho-β-galactosidase (P-β-gal) or β-galactosidase (β-gal) activity, or both. P-β-gal activity of L. curvatus and L. sake was induced and detected only in the presence of lactose or galactose. Furthermore, catabolite repression by glucose was demonstrated. The immunological properties of the P-β-gal enzymes of these organisms resemble those of Lactococcus lactis . Several strains of L. sake but none of L. curvatus exhibited β-gal activity which was constitutive. In hybridisation experiments, the β-gal genes of L. sake and L. casei ATCC393 showed over 60% DNA-homology. The presence of β-gal genes in L. sake was demonstrated in both β-gal-producing and non-producing strains. This observations is consistent with a genetic potential of lactic acid bacteria exceeding their physiological capabilities.     

Citrate metabolism in Lactobacillus casei and Lactobacillus plantarum

Information on the factors influencing citrate metabolism in lactobacilli is limited and could be useful in understanding the growth of lactobacilli in ripening cheese. Citrate was not used as an energy source by either Lactobacillus casei ATCC 393 or Lact. plantarum 1919 and did not affect the growth rate when co-metabolized with glucose or galactose. In growing cells, metabolism of citrate was minimal at pH 6 but significant at pH 4·5 and was greater in cells co-metabolizing galactose than in those co-metabolizing glucose or lactose. In non-growing cells, optimum utilization of citrate also occurred at pH 4·5 and was not increased substantially by the presence of fermentable sugars. In both growing and non-growing cells, acetate and acetoin were the major products of citrate metabolism; pyruvate was also produced by non-growing cells and was transformed to acetoin once the citrate was exhausted. Citrate was metabolized more rapidly than sugar by non-growing cells; the reverse was true of growing cells. Citrate metabolism by Lact. plantarum 1919 and Lact. casei ATCC 393 increased six- and 22-fold, respectively, when the cells were pre-grown on galactose plus citrate than when pre-grown on galactose only. This was probably due to induction of citrate lyase by growth on citrate plus sugar. These results imply that lactobacilli, if present in large enough numbers, can metabolize citrate in ripening cheese in the absence of an energy source.     

Evaluation of random amplified polymorphic DNA (RAPD)-PCR as a method to differentiate Lactobacillus acidophilus,Lactobacillus crispatus,Lactobacillus amylovorus,Lactobacillus gallinarum,Lactobacillus gasseri,and Lactobacillus johnsonii

The technique random amplified polymorphic DNA (RAPD)-PCR was evaluated as a method to differentiate Lactobacillus acidophilus, Lactobacillus crispatus, Lactobacillus amylovorus, Lactobacillus gallinarum, Lactobacillus gasseri, and Lactobacillus johnsonii. Representative strains, including the type of each species, were selected from different clusters obtained by numerical analysis of total soluble cell protein patterns. Results obtained by RAPD-PCR corresponded well with results obtained by numerical analysis of total soluble cell protein patterns. The type strains of each species displayed different RAPD profiles. Strains with identical L(+)- nicotinamide adenine dinucleotide-dependent lactic dehydrogenase (nLDH) electrophoretic profiles could be distinguished on the basis of their RAPD profiles.