低聚异麦芽糖对干酪中鼠李糖乳杆菌促生长的研究

将鼠李糖乳杆菌作为益生菌添加到契达干酪中,研究添加低聚异麦芽糖对鼠李糖乳杆菌生长的影响。以干酪组成成分、益生菌活菌数、蛋白水解以及感官评价为指标,确定低聚异麦芽糖的最适添加量,同时研究低聚异麦芽糖的添加对干酪质构是否存在影响。实验表明,添加1%的低聚异麦芽糖可以有效的促进鼠李糖乳杆菌的生长,在此条件下,鼠李糖乳杆菌在新鲜干酪中的活菌数为8.27 g-1(对数值),在干酪成熟24周后的活菌数为8.23 g-1(对数值),同时低聚异麦芽糖和鼠李糖乳杆菌的添加对干酪的蛋白水解和质构无显著性的影响。对所制成的干酪进行模拟胃肠道实验,并对其中的鼠李糖乳杆菌活菌数进行测定,最终测定出其活菌数可以保持在7.0 g-1(对数值)以上,能够起到益生作用。     

两株干酪乳杆菌的鉴定及其抑菌性的研究

本实验从内蒙古牧区牧民家庭的传统乳制品样品中分离得到两株干酪乳杆菌,其中一株在代谢过程中能产生蛋白质性质的抑菌物质.     

干酪乳杆菌纯种发酵燕麦乳工艺及其产品质量分析

针对目前益生菌发酵乳制品多为混合菌种发酵动物源乳制品的研究现状,本研究以燕麦为主要原料,通过制备纯燕麦乳,酶解,添加20%牛乳和7%蔗糖以及适量乳化剂与稳定剂,组成发酵培养基,以发酵乳制品中选育出的生长繁殖力强,发酵活力高的干酪乳杆菌05-20为试验菌株,研究接种量、发酵温度、发酵时间等单因素对干酪乳杆菌纯种发酵燕麦乳产品质量的影响。采用响应面试验优化干酪乳杆菌纯种发酵燕麦乳产品的工艺条件,分析干酪乳杆菌纯种发酵燕麦乳的产品质量,包括:感官、理化与营养成分、益生菌活菌含量与功能性成分、食品安全性、贮藏稳定性。结果表明:干酪乳杆菌纯种发酵燕麦乳的最适工艺条件为:接种量5.0%,发酵温度37℃,发酵时间5.3 h。该发酵乳呈微黄色,质地均匀细腻,酸甜可口,具有浓郁的燕麦香气和发酵香气,发酵乳活菌数达8.8×108 CFU/mL,滴定酸度49.05°T,蛋白质含量1.76 g/100 g,脂肪含量0.75 g/100 g,必需氨基酸含量占总氨基酸含量的55.92%,不饱和脂肪酸含量约占总脂肪酸含量的79.20%,燕麦β-葡聚糖的含量(92.00±1.29)μg/mL,总酚含量(13.00±0.38)μg/mL,抗消化物质质量分数(19.61±0.02)%,未检测出致病微生物和毒素,保质期为24 d。研究结果为工业化生产以植物蛋白燕麦为主的干酪乳杆菌纯种发酵乳制品提供了理论依据,也为新型益生菌发酵其它植物蛋白乳制品提供了新途径。     

酥油奶渣制品中乳杆菌分离鉴定

酥油奶渣是云南中甸地区的一种传统乳制品。对酥油奶渣制品中乳杆菌进行调查，由２６份样品中，共分离到４９株乳杆菌，鉴定出１８种（亚种），其中发酵乳杆菌、德氏乳杆菌、植物乳杆菌、棒状乳杆菌等四种，占６０％，是酥油奶渣制品中的优势种群。同时进行的发酵性能试验证明部分菌株有较好的产香产酸性能。     

新疆地区不同酸奶中优势乳酸菌的分离与鉴定

在乳制品工业中乳酸菌被认为是重要的益生菌之一。本文对来自新疆的酸驼奶、酸牛奶、酸马奶、酸羊奶以及俄罗斯酸奶中的优势乳酸菌进行分离,结合16S rRNA序列同源性分析和生理生化试验,鉴定出几种优势乳酸杆菌,即发酵乳杆菌、干酪乳杆菌、植物乳杆菌、戊糖乳杆菌。     

干酪乳杆菌纯种发酵大豆乳培养基的优化调配

从益生菌乳制品中自行分离选育出的生长繁殖力强、发酵活力高的干酪乳杆菌(05-20)为试验菌株,研究了牛乳和蔗糖在大豆乳中的添加量对干酪乳杆菌在大豆乳中发酵的凝乳时间、凝乳时活菌数、pH值、滴定酸度及产品感官风味的影响,通过方差分析确定了发酵培养基中牛乳和蔗糖的最适添加量分别为20%和7%,完成了以大豆乳作为干酪乳杆菌最佳载体的初步探索,为进一步研制开发益生菌发酵大豆乳制品奠定了基础.     

比较基因组学揭示鼠李糖乳杆菌Probio-M9在种内的基因组差异

鼠李糖乳杆菌是人和动物肠道的共生菌,在食品、医药和动物养殖等多个领域均有应用。本文以鼠李糖乳杆菌Probio-M9全基因组为对象,结合NCBI公开的214株鼠李糖乳杆菌基因组序列进行比较基因组学分析,解析不同鼠李糖乳杆菌基因组差异。结果发现,215株鼠李糖乳杆菌共识别到16 915个泛基因,247个核心基因;后续通过247个核心基因构建系统发育树,分离源和分离地不存在明显聚类趋势。鼠李糖乳杆菌Probio-M9处在分支最大的分支Ⅱ中,该分支各菌株之间的遗传关系近,差异很小,区分难度大;对分支Ⅱ中98株鼠李糖乳杆菌进行RAST注释分析,鼠李糖乳杆菌虽在功能方面整体存在高度相似性,但其中部分菌株与鼠李糖乳杆菌Probio-M9存在一定差异,相较于其它鼠李糖乳杆菌,鼠李糖乳杆菌Probio-M9具有更强的自身代谢、转录、运输等方面的调控能力,并且含有与益生功能相关的基因,如谷胱甘肽(gshAB)、胞外多糖(rmlA~rmlD、epsH)及提高宿主代谢能力(tagE)相关基因。通过比较基因组学揭示鼠李糖乳杆菌Probio-M9在种内的基因组差异,为鼠李糖乳杆菌Probio-M9的开发及应用奠定了基础。     

人体健康的保护者——益生菌和益生元的双效作用

正常见益生菌主要指两大类乳酸菌群:一类为双歧杆菌,常见的有婴儿双歧杆菌、长双歧杆菌、短双歧杆菌、青春双歧杆菌等;另一类为乳杆菌,如嗜酸乳杆菌、干酪乳杆菌、鼠李糖乳杆菌、植物乳杆菌和罗伊氏乳杆菌等。应用于人体的益生菌有双歧杆菌、乳杆菌、芽孢杆菌和酵母菌等。从安全性考虑,目前工业用益生菌主要来源于健康人体、动物和传统食物(发酵乳制品、泡菜、纳豆等发酵食品)。     

不同乳杆菌缓解慢性酒精性肝损伤的作用比较

该文探究不同乳杆菌对小鼠慢性酒精性肝损伤的缓解作用。利用C57BL/6小鼠,随机分为空白对照组、酒精模型组、阳性对照组和乳杆菌干预组。8周后,通过分析小鼠的血清转氨酶活性、肝脏氧化指标、血清内毒素含量、肝脏炎症因子表达、肠道紧密连接蛋白表达水平等,并进行肝组织病理学观察,从而比较不同乳杆菌对慢性酒精性肝损伤的缓解作用。结果表明,所选乳杆菌均能够一定程度地改善慢性酒精引起的小鼠肝损伤。其中,植物乳杆菌LP45(Lactobacillus plantarum 45,LP45)和鼠李糖乳杆菌L519(Lactobacillus rhamnosus 519,L519)效果最为显著。植物乳杆菌LP45和鼠李糖乳杆菌L519显著降低了慢性酒精引起的肝脏脂肪积累和氧化应激,抑制了血液中转氨酶和内毒素的增加,降低了肝脏中炎症因子的升高,并改善了肠道紧密连接蛋白表达的降低。因此,所选乳杆菌中,植物乳杆菌LP45和鼠李糖乳杆菌L519可以通过改善氧化应激和增强肠道屏障功能从而有效缓解小鼠慢性酒精性肝损伤。     

益生性植物乳杆菌的体外抗氧化活性研究

对从内蒙古奶豆腐及新生儿肠道中分离的5株植物乳杆菌的抗氧化活性进行分析.将保存的5株植物乳杆菌用MRS液体培养基活化培养后,对其耐酸特性、耐胆盐特性、疏水性和抗氧化能力进行分析.结果表明,5株植物乳杆菌均具有一定的耐酸和耐胆盐特性,其中植物乳杆菌MGSHC4302能够耐受pH=2.0的酸性环境,植物乳杆菌CRFA4608、MGSHC4301和MGSHC4302能够耐受1.0％的胆盐:5株植物乳杆对二甲苯和三氯甲烷的疏水性明显好于LGG,表明这些菌株具有较好的黏附性.实验结果表明,植物乳杆菌CRFA4608和MGSHC4302对羟自由基的清除能力高于对照菌株鼠李糖乳杆菌LGG,除植物乳杆菌MGSHC4303外其他4株茵对DPPH的清除能力均高于鼠李糖乳杆菌LGG或与之相近,而植物乳杆菌MGSHC4302、MGSHC4303具有较高的超氧阴离子清除能力.综上所述,植物乳杆菌MGSHC4302可以作为今后开发具有益生性产品的潜在菌株.     

Microbiological study of semi-hard goat's milk cheese (Majorero)

The development of microbial flora in industrially produced semi-hard cheese made from pasteurized goat's milk was studied during manufacture and over a 90-day ripening period.
Estimates of total count, streptococci, lactobacilli, leuconostocs, coliforms, micrococci and staphylococci, Staphylococcus aureus and yeasts and moulds were carried out at various stages of the ripening process; streptococci and lactobacilli were identified by species.
Initially, the total count increased rapidly, primarily as a result of the growth of mesophilic lactic streptococci mainly Streptococcus lactis and Strep, cremoris. Subsequently, both these counts stabilized or decreased. Lactobacilli increased, and by the end of the ripening period were the predominant microorganisms. Most common were Lactobacillus casei var. casei. , especially at the end of storage; L. casei var. rhamnosus , L. casei var. plantarum and L. cellobiosus were also isolated. Leuconostocs were not found in any of the cheeses, and hence no eye formation took place. Coliforms, enterococci, yeasts and moulds remained below 10²–10³ c.f.u. g⁻¹. Maximum levels of micrococci and staphylococci were found after 15–30 days of ripening and decreased gradually towards the end of the ripening period. Neither the milk curd, nor cheese contained Staph. aureus.     

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.     

Detection of antifungal properties in Lactobacillus paracasei subsp. paracasei SM20, SM29, and SM63 and molecular typing of the strains

Lactobacilli isolated from different food and feed samples such as raw milk, cheese, yoghurt, olives, sour dough, as well as corn and grass silage, were screened for their antifungal activities. Out of 1,424 isolates tested, 82 were shown to be inhibitory to different yeasts (Candida spp. and Zygosaccharomyces bailii) and a Penicillium sp., which were previously isolated from spoiled yoghurt and fruits. Carbohydrate fermentation patterns suggested that a substantial portion, 25%, belonged to the Lactobacillus casei group, including L. casei, L. paracasei, and L. rhamnosus. The isolates SM20 (DSM14514), SM29 (DSM14515), and SM63 (DSM14516) were classified by PCR using species-specific primers to target the corresponding type strains (L. casei, L. paracasei, and L. rhamnosus) as controls. Further molecular typing methods such as randomly amplified polymorphic DNA, pulsed-field gel electrophoresis, and sequencing analysis of the 16S rRNA gene allowed classifying strains SM20, SM29, and SM63 as L. paracasei subsp. paracasei in accordance with the new reclassification of the L. casei group proposed by Collins et al.     

Influence of autochthonous Argentine goat lactobacillus in ripening of slurry cheese models

Three indigenous lactobacilli isolated from autochthonous Argentinean goat cheeses were evaluated in models of ripening of semihard goat cheeses made under microbiologically controlled conditions. Batches A, B and C were manufactured with single strain of Lactobacillus plantarum ETC17, Lactobacillus rhamnosus ETC14 and Lactobacillus casei ETC19, respectively. Lactobacilli counts showed higher values on batch C until ripening on day 18. Chemical composition did not show differences between batches. Batch C showed a higher decrease in pH on day 1, higher liberation of nitrogen water-soluble cheese extracts and higher free amino acids content up to day 18. Amino acid distribution was analysed by studying the main components.     

乳杆菌发酵对黑米多酚含量及组成的影响

以植物乳杆菌（Lactobacillus plantarum 115,LP）、嗜酸乳杆菌（Lactobacillus acidophilus 14,LA）、干酪乳杆菌（Lactobacillus casei GB,LC）、保加利亚乳杆菌（Lactobacillus bulgaricus 134,LB）、副干酪乳杆菌（Lactobacillus paracasei 37,LPC）和鼠李糖乳杆菌（Lactobacillus rhamnosus GG,LGG）为发酵菌种,研究乳杆菌发酵对黑米游离酚和结合酚的含量及组成的影响。结果表明,6株乳杆菌发酵均显著提高了黑米游离酚的含量,但不同乳杆菌发酵后提高的程度具有显著差异,其中提高最显著的是LB。不同乳杆菌发酵后黑米中9种游离态和结合态单体酚的含量变化存在显著差异,其中,6株乳杆菌发酵后黑米中游离态的香草酸和对羟基苯甲酸的含量均显著降低（P<0.05）,LP菌株除外游离态咖啡酸的含量均显著提高（P<0.05）,而6株乳杆菌发酵后结合态阿魏酸含量均显著降低（P<0.05）。该研究为黑米的高效利用和天然活性产品的开发提供参考。     

6株乳酸菌在豆乳中的发酵特性

以干酪乳杆菌(Lactobacillus casei)、短乳杆菌(L.brevis)、嗜酸乳杆菌(L.acidophilus)、植物乳杆菌(L.plantarum)、鼠李糖乳杆菌(L.rhamnosus)和保加利亚乳杆菌(L.bulgaricus)分别发酵豆乳,测定发酵期间pH值、滴定酸度、游离氨基氮,发酵结束后的活菌数和质构参数,并且对所得产品进行感官评价。结果表明:发酵过程中前5株菌发酵豆乳的pH值显著下降,而L.bulgaricus下降缓慢,发酵24 h pH值仅为5.2。这6株菌发酵产品的活菌数均达到1.0×108 CFU/mL以上。结果表明L.casei、L.brevis、L.acidophilus和L.plantarum发酵得到的产品的坚实度、稠度、黏度、黏附性指数均较高,感官评定结果表明这4株菌发酵豆乳产品得分均较高,容易被消费者接受,适合用于生产发酵豆乳产品。     

Characterisation of the Lactobacillus community in traditional Karst ewe's cheese

Ewe's cheese, produced in the Slovenian Karst region, was analysed for its lactobacilli population. Biochemical fingerprinting with PhenePlate™ LB grouped lactobacilli in 16 distinct PhP types. One representative from each PhP type was further analysed. Members of Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus curvatus, and Lactobacillus brevis species were determined phenotypically. The genus-specific DNA band was amplified with all PhP representatives, whereas species-specific polymerase chain reaction efficiently determined only L. paracasei and L. brevis. Lactobacilli were highly to moderate sensitive to six antibiotics, and resistant to vancomycin. From halo formation in the agar spot method, indicators exerted a promising level of sensitivity for antimicrobials, produced by test microorganisms. Lactobacilli from Karst ewe's cheese offer a remarkable reservoir of 'natural' microbes.     

5株发酵食品源乳酸菌的抗药性分析

以实验室前期分离自混合果蔬酵素的植物乳杆菌(Lactobacillus plantarum S)、分离自树莓酵素的植物乳杆菌(L. plantarum WD)和分离自不同奶制品的保加利亚乳杆菌(L. bulgaricus LB-DR)、鼠李糖乳杆菌(L. rhamnosus Lr-05-281)与干酪乳杆菌(L. casei D-400)5株乳酸菌为研究对象,采用平板药敏纸片扩散法、PCR及RT-PCR技术从表型、基因型以及基因表达几个方面分析菌株的抗药性。结果表明5株菌对氨基糖苷类、喹诺酮类、糖肽类抗生素、多粘菌素B均有抗性;对大环内酯类、四环素类、磺胺类抗生素、呋喃妥因均敏感,并有较为相似的耐药谱;而对不同的β-内酰胺类抗生素敏感性不同;5株乳酸菌均含有质粒,供试的12个抗性基因中,在质粒上检测到erm、aph、vanⅠ、aacⅠ4种抗性基因,基因组DNA上检测到aph、erm、vanⅠ、blaⅡ、aacⅠ、aacⅡ6种抗性基因。部分抗性基因在MRS和加抗生素的MRS培养下会表达,不表达的抗性基因在相应抗生素诱导的条件下其抗性基因不表达。L. plantarum WD菌株质粒上因只含一种vanⅠ抗性基因,其应用安全性较好。     

复合乳酸菌在发芽糙米乳中的发酵特性

将植物乳杆菌、鼠李糖乳杆菌、嗜酸乳杆菌、干酪乳杆菌4种乳酸菌经三三组合后作为复合发酵剂对发芽糙米乳进行发酵,通过分析酸度、活菌数、脱水收缩作用敏感性、蛋白质分解力、流变学性质等实验结果,对各乳酸菌组合的发酵特性进行评价,最终筛选出适合发酵发芽糙米乳的最佳菌株组合。结果表明:植物乳杆菌-嗜酸乳杆菌-干酪乳杆菌组合所得到的发酵发芽糙米乳具有较高的品质。该发酵糙米乳在4℃条件下贮藏21 d后酸化程度较弱,下降了0.71个单位;活菌数变化小且冷藏期间数量一直高于8.7(lg(CFU/m L)),游离氨基酸平均含量达0.86 mmol/L,流变学性质显示其剪切稀化作用较弱。故该乳酸菌组合较为适合发酵发芽糙米乳。     

Modulation of Th1/Th2 balance by Lactobacillus strains isolated from Kimchi via stimulation of macrophage cell line J774A.1 in vitro

Lactobacilli isolated from Kimchi, a Korean traditional food, were tested for their capacity to modulate the T helper (Th) 1/Th2 balance. Ovalbumin (OVA)-sensitized mouse splenocytes were cultured with 26 strains of lactobacilli; the highest IL-12 induction and lowest IL-4 production were then observed in 4 strains, including Lactobacillus plantarum CJLP55, CJLP56, CJLP133, and CJLP136. These strains produced a larger amount of IL-12, which enhances differentiation and activation of Th1 cells, in macrophage cell-lines more than positive control strains L. casei KCTC 3109(T) and L. rhamnosus GG, although they also induced production of IL-10, which is a suppressor of IL-12. Indeed, CJLP133-stimulated macrophages induced production of more Th1 cytokine IFN-γ and less Th2 cytokine IL-4 than KCTC 3109(T) and GG in co-cultivation with T cells. These findings suggest that lactobacilli from Kimchi may modulate the Th1/Th2 balance via macrophage activation in the hypersensitive reaction caused by Th2 cells. PRACTICAL APPLICATION: Allergic reactions including asthma and atopy are caused by predominance of Th2 response over Th1 response. Lactobacilli isolated from fermented foods such as yogurt, cheese, and Kimchi showed health-promoting activities. The present study indicated that several lactobacilli strains from Kimchi may reduce allergic reactions through macrophage-mediated induction of Th1 response.