红皮萝卜泡菜自然发酵过程中乳酸菌的动态变化

以红皮萝卜为原料,用自然发酵法泡渍,研究其发酵过程中各优势乳酸菌的消长变化规律。从四种培养基中筛选出改良的MC培养基为各类乳酸菌计数培养基,总共得到了七种明显的菌落形态特征的乳酸菌,将其依次鉴定为乳明串珠菌(Leuconostoc lactis)、乳酸乳球菌(Lactococcus lactis)、食窦魏斯氏(Weissella cibaria)、植物乳杆菌(L.plantarum)、发酵乳杆菌(L.fermentum)。对发酵过程中各种乳酸菌计数,结果显示:泡萝卜发酵前期球菌比较旺盛,发酵后期以杆菌为主。泡菜液p H达到3.5后,球菌开始消失。      

西藏曲拉中优良乳酸菌的筛选与评价

西藏曲拉是西藏传统民族乳制品的典型代表,具有蛋白质含量高、贮藏时间长等优点,在我国众多传统乳制品中独具特色。研究利用MRS培养基对曲拉样品中的微生物进行了分离纯化,筛选得到42株乳酸菌,经16S rDNA鉴定,得到肠膜明串珠（L.mesenteroides）11株、假肠膜明串珠菌（L.pseudomesenteroides）5株、肠膜明串珠菌右旋葡聚糖亚种（L.mesenteroides subsp.dextranicum）4株、粪肠球菌（E.faecalis）10株,植物乳杆菌（L.plantarum）4株、乳酸片球菌（P.acidilactici）4株、布氏乳杆菌（L.buchneri）2株、类肠膜魏斯氏菌（W.paramesenteroides）2株;经过发酵试验与耐受性试验、抑菌性试验,筛选出3株具有优良特性的乳酸菌,本研究筛选的乳酸菌可应用于乳制品的生产。     

SDS-PAGE电泳法分析朝鲜族辣白菜中乳酸菌分布

为了分析辣白菜发酵过程中乳酸菌分布,从自然发酵的自制朝鲜族辣白菜中运用平板稀释法根据细菌菌落形态特征分离筛选出59株乳酸菌,SDS-PAGE电泳法分析各菌株全细胞蛋白模式后将其划分为7大类,最后用16S rRNA序列同源性分析,鉴定出4种乳酸菌种类,分别为肠膜明串珠菌、柠檬明串珠菌、食窦魏斯氏菌和植物乳杆菌。     

南宁地区米酒曲源乳酸菌在糯米汁中氨基酸和有机酸代谢特征研究

该研究采用纯培养技术对广西省南宁地区米酒曲中乳酸菌多样性进行了解析,旨在揭示其分离株在糯米汁中产氨基酸和有机酸的特征。结果表明,11个样品共分离出20株乳酸菌,分别被鉴定为戊糖片球菌（Pediococcus pentosaceus）、融合魏斯氏菌（Weissella confuse）、类肠膜魏斯氏菌（Weissella paramesenteroides）、屎肠球菌（Enterococcus faecium）、台湾乳球菌（Lactococcus taiwanensis）、植物乳杆菌（Lactobacillus plantarum）和戊糖乳杆菌（Lactobacillus pentosus）,其中戊糖片球菌（P. pentosaceus）占分离株的35%,为南宁地区米酒曲中的优势乳酸菌。选取除屎肠球菌（E. faecium）外的16株乳酸菌分离株进行糯米汁纯种发酵,结果发现所有菌株均不产氨基酸,乳酸为糯米汁中主要有机酸。主成分分析（PCA）结果表明,融合魏斯氏菌（W. confuse）HBUAS53367产有机酸的能力较强,可用于后续进一步研究。     

基于纯培养和高通量测序技术解析仙桃地区鲊菜细菌多样性

为解析湖北省仙桃地区鲊菜中细菌多样性,该研究在采用纯培养技术对乳酸菌菌株进行分离鉴定的基础上,进一步使用Illumina Mi Seq高通量测序技术对其细菌多样性进行解析。纯培养结果发现,分离到的44株乳酸菌隶属于乳酸杆菌属（Lactobacillus）、明串珠菌属（Leuconostoc）、魏斯氏菌属（Weissella）和乳球菌属（Lactococcus）,其中植物乳杆菌（L. plantarum）和戊糖乳杆菌（L. pentosus）分别占总分离株含量的40.91%和34.09%。Illumina Mi Seq高通量测序结果显示,鲊菜中优势细菌属主要包括乳酸杆菌属、明串珠菌属、魏斯氏菌属、假单胞菌属（Pseudomonas）和肠杆菌属（Enterobacter）,其平均相对含量分别为85.03%、3.31%、1.68%、1.50%和1.05%。由此可见,仙桃地区鲊菜中乳酸菌具有较高的多样性,且以植物乳杆菌和戊糖乳杆菌为主。     

伊犁地区乳品中乳酸菌的分离及鉴定

从伊犁地区牧民家庭采集的乳品中分离得到10株乳酸菌,经过对其生物学特性的鉴定,有干酪乳杆菌假植物亚种(L.casei subsp.Plantaman)4株、鸡肠球菌(E.gallins.rum)1株、屎肠球菌(E.faecium)1株、乳酸乳球菌乳酸亚种(L.lactis subsp.cremoris)2株、肠膜明串珠菌肠膜亚种(Lc.Mesenteroides subsp.Mesenteroides)2株。通过研究发现,该鉴定菌株的生物学特性基本符合各属和种的鉴定标准,均属于中温性乳酸菌。     

内蒙古腌制沙葱中乳酸菌分离鉴定

以采集自内蒙古腌制沙葱为研究对象,通过微生物纯培养方法分离培养其中乳酸菌。应用16S r RNA基因序列分析和系统发育关系研究手段,对分离菌株进行鉴定,并与其他地区不同种类发酵蔬菜中分离得到的乳酸菌进行比较。结果表明:共分离得到6株乳酸菌,包括2株干酪乳杆菌(Lactobacillus casei),2株乳酸乳球菌乳酸亚种(Lactococcus lactis subsp lactis)、1株肠膜明串珠肠膜亚种(Leuconostoc mesenteroides subsp.mesenteroides)和1株Lactobacillus diolivorans。相比于其他地区发酵蔬菜中分离所得的乳酸菌,内蒙古腌制沙葱样品分离得到的乳酸菌数量虽少,但也具有特有菌种。     

玉米酸汤面自然发酵过程中乳酸菌的分离鉴定及特性研究

对玉米酸汤面自然发酵过程中不同时期的乳酸菌进行分离鉴定及特性研究,从中分离出5株乳酸细菌,利用现代分析技术与经典分类法对其进行了系统的细菌学鉴定.鉴定结果表明,这5株乳酸菌分别为:戊糖片球菌、乳酸乳球菌、植物乳球菌、肠膜明串珠菌、德氏乳杆菌.并测定了发酵过程中乳酸菌的数量变化及各发酵阶段的主导菌相,最后得出适宜的发酵条件.     

扬州稀甜酱中乳酸菌的分离鉴定及抑菌活性初探

以扬州稀甜酱为研究对象,采用经典乳酸菌筛选法从样品中分离、纯化乳酸菌,采用形态学观察、生理生化试验和16S rRNA序列分析对乳酸菌进行鉴定,并采用牛津杯法对发酵滤液的抑菌活性进行研究。结果表明,从扬州稀甜酱中共分离、纯化出33株乳酸菌,其中15株菌株被鉴定为屎肠球菌（Enterococcus faecium）,12株菌株被鉴定为乳酸片球菌（Pediococcus acidilactici）,4株菌株被鉴定为类肠膜魏斯氏菌（Weissella paramesenteroides）,2株菌株被鉴定为酸鱼乳杆菌（Lactobacillus acidipiscis）,屎肠球菌和乳酸片球菌为扬州稀甜酱中的优势乳酸菌。乳酸片球菌TJ17和TJ31发酵滤液对金黄色葡萄球菌（Staphylococcus aureus）、单核细胞增生李斯特氏菌（Listeria monocytogenes）和大肠埃希氏菌（Escherichia coli）均有明显的抑制作用,且乳酸片球菌TJ31抑菌效果较好。     

泡菜发酵乳酸菌的分离鉴定及耐药性分析

对吉林地区朝鲜族自制泡菜中的发酵乳酸菌进行分离鉴定,并对菌株耐药情况进行分析,以期为泡菜发酵菌的风险评估奠定基础。采集吉林省多个不同地区的泡菜制品,通过MRS培养基分离,16S rDNA测序,分析其乳酸菌种类及数量,同时采用平板琼脂稀释法进一步检测了分离菌对10 种临床常用抗生素的药物敏感性。结果表明,从15 份不同厂家泡菜中共分离得到34 株乳酸菌,分别为植物乳杆菌12 株,短乳杆菌5 株,鼠李糖乳杆菌3 株,干酪乳杆菌2 株,清酒杆菌2 株,肠膜明串珠菌2 株,嗜热链球菌2 株,食窦魏斯氏乳杆菌1 株,弯曲乳杆菌1 株,棒状乳杆菌1 株,嗜酸乳杆菌1 株,坚强肠球菌1 株,Lactobacillus namurensis 1 株。药敏实验结果表明,所有菌株对氨苄西林和氯霉素敏感,对其他抗生素均有不同程度的耐药性,其中对环丙沙星耐药率最高。     

Monitoring the lactic acid bacterial diversity during shochu fermentation by PCR-denaturing gradient gel electrophoresis

The presence of lactic acid bacteria (LAB) during shochu fermentation was monitored by PCR-denaturing gradient gel electrophoresis (DGGE) and by bacteriological culturing. No LAB were detected from fermented mashes by PCR-DGGE using a universal bacterial PCR primer set. However, PCR-DGGE using a new primer specific for the 16S rDNA of Lactococcus, Streptococcus, Tetragenococcus, Enterococcus, and Vagococcus and two primers specific for the 16S rDNA of Lactobacillus, Pediococcus, Leuconostoc, and Weissella revealed that Enterococcus faecium, Lactobacillus casei, Lactobacillus fermentum, Lactobacillus nagelii, Lactobacillus plantarum, Lactococcus lactis, Leuconostoc citreum, Leuconostoc mesenteroides, and Weissella cibaria inhabited in shochu mashes. It was also found that the LAB community composition during shochu fermentation changed after the main ingredient and water were added during the fermentation process. Therefore, we confirmed that PCR-DGGE using all three primers specific for groups of LAB together was well suited to the study of the LAB diversity in shochu mashes. The results of DGGE profiles were similar to the results of bacteriological culturing. In conclusion, LAB are present during shochu fermentation but not dominant.     

Bacterial biodiversity of traditional Zabady fermented milk

The aim of this work was to identify the bacterial biodiversity of traditional Zabady fermented milk using PCR-temporal temperature gel electrophoresis (PCR-TTGE) and PCR-denaturing gradient gel electrophoresis (PCR-DGGE). Most of the identified bacterial species in Zabady samples belonged to lactic acid bacteria (LAB), e.g., Streptococcus thermophilus, Lactococcus garvieae, Lactococcus raffinolactis, Lactococcus lactis, Leuconostoc citreum, Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus johnsonii. Using the culture-dependent and independent methods, the streptococcal and lactococcal groups appeared to be the major bacterial species in Zabady fermented milk, whereas the lactobacilli were the minor ones. The main dominant species was St. thermophilus followed by Lc. garvieae. Other molecular tools, e.g., species-specific PCR assay and cloning and sequencing strategy were used to confirm the TTGE and DGGE results. Lc. garvieae, Lc. raffinolactis, Ln. citreum, and Lb. johnsonii were identified for the first time in this type of Egyptian fermented milk.     

不同乳酸菌接种发酵泡菜风味的研究

以新鲜红皮萝卜为原料,分别接种分离自自然发酵泡菜中的乳明串株菌、乳酸乳球菌、食窦魏斯氏、发酵乳杆菌、植物乳杆菌进行纯种乳酸菌发酵制作泡菜。通过测定泡菜的乳酸菌菌相、总酸度、感官评价、挥发性成分及有机酸,对分离自自然发酵泡菜中不同乳酸菌纯种发酵泡萝卜的风味进行研究。结果表明,发酵达到终点时,接种不同乳酸菌发酵的泡菜中大部分乳酸菌的活菌数相差不大,都在7.0lg CFU/m L左右,泡菜液中的乳酸菌几乎全为植物乳杆菌;大部分乳酸菌纯种发酵泡菜中总酸含量>4g/kg;不同乳酸菌发酵的泡菜挥发性成分及有机酸的种类差异不显著。      

Interaction between Lactococcus lactis and Lactococcus raffinolactis during growth in milk: development of a new starter culture

Many milk fermentations use mixed cultures of lactic acid bacteria. To select a new mixed starter culture, 100 acid-producing bacterial strains were isolated from raw cow milk. Of these, 13 strains identified as belonging to the genera Lactococcus, Lactobacillus, Leuconostoc, or Weissella (based on phenotypic and genotypic tests) were assessed for a symbiotic effect between pairs of isolated strains during growth in milk. Among the strains tested, a mixed culture of Lactococcus lactis ssp. lactis strain 54 and Lactococcus raffinolactis strain 37 stimulated greater acid production during fermentation than occurred with pure fermentation. This stimulatory effect was not observed in milk supplemented with yeast extract or glucose or in constituted medium. Addition of a cell-free filtrate from milk fermented by strain 54 increased acid production by strain 37; however, the converse effect was not observed. The increased acid production by this mixed culture was, therefore, due to stimulation of strain 37 by metabolic products of strain 54, suggesting that the interaction between strains 54 and 37 is commensal. Analysis with a taste-sensing system indicated that fermented milk containing the mixed culture was more acidic, had more anionic bitterness, had greater aftertastes of anionic bitterness and astringency, and was less salty and umami than milk containing the individual cultures. This study identifies a new commensal relationship between 2 lactococcal strains that are commonly used for making dairy products.     

不同盐质量分数泡白菜发酵过程中乳酸菌群落结构的变化

设计3种不同盐质量分数的泡白菜,包括低盐(2%)、中盐(5%)、高盐(8%),利用可培养方法结合多种分子生物学手段研究其发酵过程中乳酸菌的群落结构。结果表明:盐质量分数越低,乳酸菌增长速率越快。本研究从3种不同盐质量分数泡白菜发酵过程中分离筛选得到了563株乳酸菌,并采用16S rDNA测序、多重聚合酶链式反应、聚合酶链反应-限制性片段长度多态性、API 50CH等多种不同的鉴定方法进行鉴定,鉴定结果表明这563株乳酸菌属于5个属11个种。结果表明,低盐泡白菜发酵前期的优势菌为Lactococcus lactis、Lactobacillus pentosus和Leuconostoc,发酵后期则由Lactobacillus pentosus主导;中高盐泡白菜发酵前期由Lactobacillus pentosus和Weissella主导,发酵后期主要由Lactobacillus pentosus完成。     

Isolation of lactic acid bacteria from Lighvan cheese, a semihard cheese made from raw sheep milk in Iran

The lactic acid bacteria contributing to Lighvan cheese ripening during the different stages of production were investigated. Isolated strains from different culture media were identified phenotypically to species and subspecies level. In total, 413 strains were isolated from raw milk, 1-day-old cheese and fully ripened cheese. The most abundant species belonged to Enterococcus faecium (87 isolates), Lactococcus lactis ssp. lactis (68 isolates), Enterococcus faecalis (55 isolates) and Lactobacillus plantarum (48 isolates). E. faecium, Lc. lactis and Lb. plantarum were the predominantly isolated strains from ripened cheese. Therefore, they may contribute considerably to the aroma and flavour development of Lighvan cheese.     

低盐泡菜中耐酸性乳酸菌的筛选''鉴定及特性研究

目的:筛选出具有潜在益生特性的乳酸菌菌株。方法:从含盐量≤6%的12份低盐泡菜中筛选出5株耐酸性乳酸菌,进行16S rDNA分子鉴定,并对其益生特性进行研究。结果:5株耐酸性乳酸菌分别为肠膜明串珠菌(Leuconostoc mesenteroides)J2、副干酪乳杆菌(Lactobacillus paracasei)N6、类植物乳杆菌(Lactobacillu paraplantarum)F8、食窦魏斯氏菌(Weissella cibaria)M1和食窦魏斯氏菌(Weissella cibaria)M12。其中,L.paracasei N6、W.cibaria M1和W.cibaria M12在pH 4.0培养基中相对生长率分别为84.23%,78.32%,76.29%,具有较强的耐酸能力;经pH 3.0胃液和pH 8.0肠液消化后,其存活率分别为79.26%,50.65%,53.37%,具有较强的耐受胃肠液能力;在0.3%胆盐中培养8 h后,其存活率均在30%以上,具有较强的耐胆盐能力;疏水率及自凝集率均在60%以上,具有较强的疏水及自凝集能力。结论:试验筛选得到3株具有益生特性的耐酸性乳酸菌菌株L.paracasei N6、W.cibaria M1和W.cibaria M12,可用于复合益生菌菌剂的研究。     

东北酸菜优良乳酸菌筛选及其抑菌特性研究

该实验从东北酸菜中分离纯化并鉴定出40种乳酸菌,主要为植物乳杆菌（Lactobacillus plantarum）、融合魏斯氏菌（Weissella confuse）、副干酪乳杆菌（Lactobacillus paracasei）、干酪乳杆菌（Lactobacillus casei）、食窦魏斯氏菌（Weissella cibaria）。通过测定乳酸菌乳酸产量及其抑制大肠杆菌（Escherichia coli）的能力,探究乳酸菌的产酸量与其抑菌作用之间相互关系。结果表明,菌株C1、E8、A5产酸能力较强,发酵12 h后发酵上清液中乳酸质量浓度＞12 g/L,抑菌圈直径＞12 mm,对大肠杆菌抑制能力强。表明东北酸菜中乳酸菌的产酸量与抑菌作用存在紧密的联系。     

Characterization of the lactic acid bacteria in ewe's milk and cheese from northwest Argentina

Indigenous lactic acid bacteria in ewe's milk and artisanal cheese were studied in four samples of fresh raw milk and four 1-month-old cheeses from the provinces of northwest Argentina. Mean growth counts on M17, MRS, and MSE agar media did not show significant differences (P < 0.05) in raw milk and cheeses. Isolates of lactic acid bacteria from milk were identified as Enterococcus (48%), lactococci (14%), leuconostocs (8%), and lactobacilli (30%). All lactococci were identified as Lactococcus lactis (subsp. lactis and subsp. cremoris). Lactobacilli were identified as Lactobacillus plantarum (92%) and Lactobacillus acidophilus (8%). Enterococci (59%) and lactobacilli (41%) were isolated from cheeses. L. plantarum (93%), L. acidophilus (5%), and Lactobacillus casei (2%) were most frequently isolated. L. lactis subsp. lactis biovar diacetylactis strains were considered as fast acid producers. L. lactis subsp. cremoris strains were slow acid producers. L. plantarum and L. casei strains identified from the cheeses showed slow acid production. The majority of the lactobacilli and Lactococcus lactis strains utilized citrate and produced diacetyl and acetoin in milk. Enzyme activities (API-ZYM tests) of lactococci were low, but activities of L. plantarum strains were considerably higher. The predominance of L. plantarum in artisanal cheese is probably important in the ripening of these cheeses due to their physiological and biochemical characteristics.