一些制品中活菌所含质粒的初步分析

我们分析了一些制品中活菌诸如双歧杆菌、乳杆菌、链球菌和腊样芽孢杆菌等所含质粒,发现保加利亚乳杆菌和嗜热链球菌中携带     

异麦芽寡糖促进肠道分离菌生长的体外实验

目的 观察添加１％异麦芽寡糖对从正常人阑尾标本中分离双歧杆菌、乳杆菌和类杆菌的体外促生长作用。方法 分别在培养前和培养１２、２４、３６ｈ和４８ｈ,用７２１分光光度计和ｐＨ计测定培养液ＯＤ值和ｐＨ值变化。结果 接种双歧杆菌的培养液ＯＤ值从０．１２８增加到１．７,ｐＨ值由７．１降到４．２,增殖效果与添加１％葡萄糖相当。接种乳杆菌的培养液ＯＤ值从０．１７增加到０．８５,ｐＨ值由７．０降到４．８,增殖效果低于添加１％葡萄糖。接种类杆菌的培养液ＯＤ值从０．１０５增加到１．６５,ｐＨ值由７．１降到５．１,增殖效果高于添加１％葡萄糖。结论 添加１％民麦芽寡糖具有促进肠道分离菌双歧杆菌、乳杆菌和类杆菌生长的作用。     

青岛地区成年人肠菌群正常值的调查

本文采用６种选择性培养基和２种非选择性培养基,应用形态学,常规生化反应,酶学反应等技术,对青岛地区的３０例健康青年人和３０例健康老年人的粪便菌群中肠杆菌、肠球菌、葡萄球菌及厌氧菌群中的拟杆菌、双歧杆菌、乳杆菌等６种细菌进行分离、培养、计数和鉴定。结果显示：健康青年人粪便菌群中６类菌活菌范围是：肠杆菌９．２１±０．３９,肠球菌７．７４±０．５３,葡萄球菌５．１３±１．５７,拟杆于菌１０．４１±０．５４,双歧杆菌１０．８４±０．４８,乳杆菌７．８４±０．４９。健康老年人粪便菌群中６类菌的活菌范围分别是：肠杆菌８．６１±０．４８,肠球菌７．５４±０．８２,葡萄球菌５．４６±１．７７,拟杆菌９．４１±０．３７,双歧杆菌９．８２±０．５０,乳杆菌８．２２±０．６５（ＬｏｇＮ／克）。     

益生菌类保健食品中益生菌的检测

随着微生态学的深入发展 ,微生态调节剂也迅猛地发展起来。从上世纪梅奇尼科夫在欧洲提倡饮用酸牛奶以来 ,微生态调节剂逐渐风行于世界各地。近十年来 ,微生态制剂在我国的发展也十分迅速 ,其中大部分为益生菌制剂 ,除一少部分为正式药品用于临床外 ,大多为保健食品。目前我国卫生部批准的可用于保健食品的益生菌菌种有 :两歧双歧杆菌、婴儿双歧杆菌、短双歧杆菌、长双歧杆菌、青青双歧杆菌、保加利亚杆菌、嗜酸乳杆菌、干酪乳杆菌、嗜热链球菌。益生菌类保健食品在其审批过程中 ,其益生菌菌种要求经过卫生部认定部门的系统鉴定 ,规定其活菌…     

多菌种酸奶中活性乳酸菌的计数方法研究

利用4种选择性培养基MRS、MRS-山梨醇、MRS-5．2、Elliker,采用平板涂布法和倾注接种法。在蜡烛缸法（缺氧）、封口膜法（微氧）和供氧条件下对4种市售多菌种酸奶中保加利亚乳杆菌、嗜热链球菌、嗜酸乳杆菌、双歧杆菌进行选择性计数方法研究。结果表明：蜡烛缸法较能反映乳酸菌活菌数量的实际情况,封口膜法次之;在不同培养条件下4种选择性培养基对于乳酸菌活菌的计数都是灵敏的;而涂布法和倾注法接种活菌数有显著差异,倾注法要优于涂布法。     

蝴蝶兰根段的组织培养

１　植物名称　蝴蝶兰（ＰｈａｌａｅｎｏｐｓｉｓＭｅｌｌｅｒＧｏｌｄ“ＮＦＳ”）。２　材料类别　根段。３　培养条件　（１）愈伤组织的诱导及分化培养基：Ｂ５＋ＮＡＡ１．５ｍｇ·Ｌ－１（单位下同）＋ＫＴ０．２＋ＣＭ１５０ｍｌ·Ｌ－１＋３％蔗糖;（２）原球茎增殖培养基：Ｂ５＋ＧＡ０．０５＋ＣＨ１２０＋３％蔗糖;（３）小苗生长培养基：１／２ＭＳ＋２０％香蕉泥＋２％蔗糖;（４）诱导生根培养基：１／２ＭＳ＋ＩＢＡ０．３＋２％蔗糖。上述培养基均加０．２％活性炭,０．５８％琼脂粉,ｐＨ为５．５;培养基在１２１℃高…     

金双歧治疗功能性便秘临床应用

“口服双歧杆菌、乳杆菌、嗜热链球菌三联活菌片”属于微生态制剂,临床上用于治疗肠道菌群失调引起的腹泻、慢性腹泻、抗生素治疗无效的腹泻及便秘。其药效成分是长双歧杆菌、保加利亚乳杆菌、嗜热链球菌3种健康人体肠道正常生理性细菌,可在人体肠道中生长繁殖。其药理作用是通过直接补充人体正常生理细菌,调整肠道菌群平衡,抑制并清除肠道中对人具有潜在危害的细菌,从而达到治疗腹泻及便秘的目的。“口服双歧杆菌、乳杆菌、嗜热链球菌三联活菌片”,商品名为金双歧。金双歧在临床上应用较为广泛,获得医护工作者及患者的一致好评。现将金双歧…     

固定化共生发酵无醇饮料的研究

以大麦和大米为主料,优质红茶为辅料,采用海藻酸钠包埋法固定酵母菌、嗜酸乳杆菌、弱氧化醋酸菌,混合装填固定化细胞反应柱,连续发酵生产无醇饮料。试验表明：麦茶汁１２°Ｂｘ,ｐＨ６５,２５℃,反应柱内固定化各菌种凝胶比例为酵母菌：嗜酸乳杆菌：弱氧化醋酸菌＝０．７：１：２,停留时间９～１３ｈ,相当于游离细胞发酵１０ｄ的效果。流出液含Ｌ－乳酸１．６５～１．９８ｇ／Ｌ,总酸２．６２４～３．０３２ｇ／Ｌ,酒精０７％～１．３２％。制成的新型发酵无醇饮料呈淡黄色,泡沫洁白细腻,含有多种人体必需氨基酸和维生素,以及具有保健作     

芽孢杆菌E2菌株纤维素酶性质的研究

芽孢杆菌Ｅ２菌在５５℃下生长良好,在培养液中能大量积累胞外纤维素酶（１９０ｍｕ／ｍＬ培养液）,所产生的纤维素普单一的羧甲基纤维素酶（ＣＭＣａｓｅ）。羧甲基纤维素钠（ＣＭＣＮａ）为其专一性底物。该酶作用的ｐＨ为４．５－８．０;最适ｐＨ为６．５－７．０;在ｐＨ４．０－８．０范围内较稳定,酶作用的最适温度为５５℃;在６０℃处理１０,３０,６０,９０以及１２０分钟后,残余酶活分别为９５％,８０．３％,４０     

酷酸梭菌——婴儿型双歧杆菌二联活菌制剂对人体肠道菌群的调节试验

目的 观察酷酸梭菌－－婴儿型双歧杆菌二联活菌制剂对受试人群肠道菌群的影响。方法 检测受试者服用前后的肠道菌群并计数。结果 肠杆菌、肠球菌、拟杆菌的数量无明显变化,双歧杆菌、乳杆菌的数量明显增加,差异有非常显著性（Ｐ〈０．０１）,结论 酪酸梭菌－－婴儿型双歧杆菌二联活菌制剂具有一定的调节人体肠道菌群、增殖双歧杆菌和乳杆菌的作用。     

Characteristics of Lactobacillus strains contained in pharmaceuticals]

The aim of the study was to characterize lactic acid bacteria (LAB) which are components of drugs administered orally in cases of intestinal disturbances, or antibiotic--related diarrhea. Biochemical properties, growth behavior, bile tolerance, and survival at low pH of six LAB strains (four strains L. rhamnosus and two L. acidophilus) were studied. The survival at low pH was determined in MRS broth (Difco) acidified to pH 1; 2; 3; and 4. Bile tolerance was tested on MRS broth with 0.3% oxgall (Difco). Between tested strains differences in ability to grow at low pH and survival in bile were observed. Only 0.01% inoculum of all examined strains survived at pH 1. Differences between strains in survival at low pH (pH 2 and pH 3) and tolerance of bile were observed. However, after 2 h incubation at pH 4, 100% of strains stayed alive. Examined strains demonstrated good 3% bile tolerance. All strains met the criteria for probiotic strains: ability to survive at pH 3 and in the presence of bile.     

Utilization of UF-permeate for production of beta-galactosidase by lactic acid bacteria

Four lactobacilli strains (Lactobacillus bulgaricus, Lactobacillus acidophilus, Lactobacilus casei and Lactobacillus reuteri) were grown in MRS broth and three lactococci strains (Streptococcus thermophilus, Lactococcus lactis subsp. Lactis and Lactococcus lactis subsp. lactis biovar. diacetilactis) were grown in M17 broth. L. reuteri and S. thermophilus were chosen on the basis of the best mean beta-galactosidase activity of 10.44 and 10.01 U/ml respectively, for further studies on permeate-based medium. The maximum production of beta-galactosidase by L. reuteri was achieved at lactose concentration of 6%, initial pH 5.0-7.5, ammonium phosphate as nitrogen source at a concentration of 0.66 g N/L and incubation temperature at 30 degrees C/24 hrs to give 6.31 U/ml. While in case of S. thermophilus, maximum beta-galactosidase production was achieved at 10% lactose concentration of permeate medium, supplemented with phosphate buffer ratio of 0.5:0.5 (KH2PO4:K2HPO4, g/L), at initial pH 6.0-6.5, ammonium phosphate (0.66g N/L) as nitrogen source and incubation temperature 35 degrees C for 24 hrs to give 7.85 U/ml.     

Evaluation of enrichment broths for their ability to recover heat-injured Listeria monocytogenes

J.R. PATEL AND L.R. BEUCHAT. 1995. Listeria selective enrichment broth (LEB), University of Vermont (UVM) broth, modified UVM (MUVM) broth and Fraser broth (FB) were compared for their ability to recover cells of L. monocytogenes from heated tryptose phosphate broth. Three strains of L. monocytogenes were heated at 54C for 30 min, inoculated into enrichment broths supplemented with 400 µg catalase ml⁻¹, and incubated for 8 h at 30°C. After incubation for 4 h, the total viable cell populations either decreased or did not change, whereas the number of healthy (non-injured) cells of all strains increased significantly in all broths except FB inoculated with the LCDC strain. With an increase in incubation time to 8 h, the number of healthy cells of all strains increased in all broths. At 8 h, the difference between populations of total (injured plus healthy cells) and healthy cells detected in LEB inoculated with two strains was not significant. Overall, recovery of heat-treated cells was significantly higher in LEB, followed by MUVM broth, UVM broth and FB. The addition of catalase to enrichment broths significantly enhanced recovery of heat-injured cells. A slight reduction of catalase activity of heated cells of all test strains in all enrichment broths except FB was observed by extending the incubation period from 4 to 8 h. A test strain that produces relatively higher catalase activity compared to the other strains exhibited the greatest resistance to exogenous hydrogen peroxide. Enumeration of viable L. monocytogenes cells in heated foods should be done using LEB supplemented with 400 µg catalase ml⁻¹ to maximize the recovery of injured cells.     

一株广谱抑菌活性乳酸菌的筛选及特性研究

【目的】从贵州剑河采集的传统自然发酵豆酱中分离筛选具有广谱抑菌效果的乳酸菌,并进行肠道益生特性的研究。【方法】通过抑菌试验分离筛选得到菌株DJ-04,对其进行人工胃肠液耐受性、胆盐耐受性和渗透压耐受性的研究,并对其进行生理生化鉴定和16S r RNA鉴定。【结果】菌株DJ-04对大肠杆菌、沙门氏菌、金黄色葡萄球菌、志贺氏菌和铜绿假单胞菌的生长有很好的抑制作用;在p H值为2.5的人工胃液中处理3 h活菌数达到107 CFU/m L以上;在人工肠液中处理3 h活菌数达到108 CFU/m L以上,对人工胃肠液表现出良好的耐受性。能耐受一定浓度的牛胆盐,在质量浓度0.2 g/100 m L的牛胆盐环境中活菌数可达到107 CFU/m L;具有较高的渗透压耐受能力,在Na Cl质量浓度为10 g/100 m L的液体MRS中培养24 h后,活菌数仍在107 CFU/m L以上。经鉴定,DJ-04为植物乳杆菌。【结论】植物乳杆菌DJ-04具有良好的人工胃肠液耐受性以及耐胆盐和耐渗透压能力,具有肠道益生菌的潜能。     

Calcium-Induced Alteration of Cellular Morphology Affecting the Resistance of Lactobacillus acidophilus to Freezing

Examination of factors affecting the resistance of Lactobacillus acidophilus NCFM culture concentrates to freeze injury induced during frozen storage at -20°C revealed that calcium supplementation of the growth medium contributed to the storage stability of cells prepared in static culture. Culture concentrates of L. acidophilus NCFM were prepared from cells propagated in MRS broth or MRS broth supplemented with 0.1% calcium carbonate, calcium chloride, or calcium phosphate. After 28 days of frozen storage at -20°C, concentrated cells (3.2 × 10⁹ colony-forming units per ml) prepared from MRS broth cultures showed an 84% reduction in viable cells. Of the remaining viable cells, 88% were sublethally injured and unable to form colonies on MRS agar supplemented with 0.15% bile. Cells prepared in calcium-supplemented MRS broths demonstrated more resistance to frozen storage. Viability and injury losses in the frozen concentrates were limited to 10 to 39% and 3 to 23%, respectively. It was observed that calcium supplementation of MRS medium resulted in a morphological transition of L. acidophilus NCFM from filamentous to bacilloid rods, and the bacilloid cells were more resistant to freezing and storage at conventional freezer temperatures. The results suggest that the morphology of the L. acidophilus cell may be an important consideration in the preparation of freeze-stable culture concentrates.     

Streptococcus thermophilus and its biosurfactants inhibit adhesion by Candida spp. on silicone rubber.

The adhesion of yeasts, two Candida albicans and two Candida tropicalis strains isolated from naturally colonized voice prostheses, to silicone rubber with and without a salivary conditioning film in the absence and presence of adhering Streptococcus thermophilus B, a biosurfactant-releasing dairy isolate, was studied. Coverage of 1 to 4% of the surface of silicone rubber substrata with adhering S. thermophilus B gave significant reductions in the initial yeast adhesion regardless of the presence of a conditioning film. Mechanistically, this interference in yeast adhesion by S. thermophilus B was not due to direct physical effects but to biosurfactant release by the adhering bacteria, because experiments with S. thermophilus B cells that had released their biosurfactants prior to adhesion to silicone rubber and competition with yeasts did not show interference with initial yeast adhesion. The amounts of biosurfactants released were highest for mid-exponential- and early-stationary-phase bacteria (37 mg.g of cells-1 [dry weight]), but biosurfactants released by stationary-phase bacteria (14 mg.g of cells-1 [dry weight]) were the most surface active. The crude biosurfactants released were mixtures of various components, with a glycolipid-like component being the most surface active. A lipid-enriched biosurfactant fraction reduced the surface tension of an aqueous solution to about 35 mJ.m-2 at a concentration of only 0.5 mg.ml-1. The amount of biosurfactant released per S. thermophilus B cell was estimated to be sufficient to cover approximately 12 times the area of the cross section of the bacterium, making biosurfactant release a powerful defense weapon in the postadhesion competition of the bacterium with microorganisms such as yeasts. Preadsorption of biosurfactants to the silicone rubber prior to allowing yeasts to adhere was as effective against C. albicans GB 1/2 adhesion as covering 1 to 2% of the silicone rubber surface with adhering S. thermophilus B, but a preadsorbed biosurfactant layer was less effective against C. tropicalis GB 9/9.     

Acid tolerance of biofilm cells of Streptococcus mutans

Streptococcus mutans, a member of the dental plaque community, has been shown to be involved in the carious process. Cells of S. mutans induce an acid tolerance response (ATR) when exposed to sublethal pH values that enhances their survival at a lower pH. Mature biofilm cells are more resistant to acid stress than planktonic cells. We were interested in studying the acid tolerance and ATR-inducing ability of newly adhered biofilm cells of S. mutans. All experiments were carried out using flow-cell systems, with acid tolerance tested by exposing 3-h biofilm cells to pH 3.0 for 2 h and counting the number of survivors by plating on blood agar. Acid adaptability experiments were conducted by exposing biofilm cells to pH 5.5 for 3 h and then lowering the pH to 3.5 for 30 min. The viability of the cells was assessed by staining the cells with LIVE/DEAD BacLight viability stain. Three-hour biofilm cells of three different strains of S. mutans were between 820- and 70,000-fold more acid tolerant than corresponding planktonic cells. These strains also induced an ATR that enhanced the viability at pH 3.5. The presence of fluoride (0.5 M) inhibited the induction of an ATR, with 77% fewer viable cells at pH 3.5 as a consequence. Our data suggest that adhesion to a surface is an important step in the development of acid tolerance in biofilm cells and that different strains of S. mutans possess different degrees of acid tolerance and ability to induce an ATR.     

海藻糖对乳酸菌的抗逆保护研究

研究了在冷冻干燥、高温及冻融等胁迫条件下，海藻糖对嗜热链球菌（Ｓｔｒｅｐｔｏｃｏｃｃｕｓ ｔｈｅｒ－ ｍｏｐｈｉｌｌｕｓ）和植物乳杆菌（Ｌａｃｔｏｂａｃｉｌｌｕｓ ｐｌａｎｔａｒｕｍ）菌体细胞的保护作用。结果表明在冷冻干燥过程 中，海藻糖保护的细胞存活率分别达７５％和３３％，而对照分别为１９％和ｌ％；用９０℃高温处理干燥 状态和溶液状态的嗜热链球菌，证明海藻糖能明显提高细胞的耐热性；用冻融法反复处理嗜热链球 菌４次和８次，加海藻糖保护的细胞存活率显著高于对照。在扫描电镜下观察这     

Production of gamma-aminobutyric acid (GABA) by Lactobacillus buchneri isolated from kimchi and its neuroprotective effect on neuronal cells

Lactic acid bacteria that accumulated gamma-aminobutyric acid (GABA) in culture medium were screened to identify strains with high GABA-producing ability. One strain, MS, which was isolated from kimchi, showed the highest GABA-producing ability among the screened strains. MS was identified as Lactobacillus buchneri based on Gram-staining, metabolic characteristics, and 16S rDNA sequence determination. Optimum culture conditions for GABA production were determined: MRS broth containing 5% MSG, 1% NaCl, and 1% glucose, at an initial pH of 5.0, the incubation temperature at 30 degrees C for 36 h. Under these conditions, MS produced GABA at a concentration of 251 mM with a 94% GABA conversion rate. Moreover, culture extracts of Lb. buchneri MS partially or completely protected neuronal cells against neurotoxicant-induced cell death.     

Development and Characterization of Lactose-Positive Pediococcus Species for Milk Fermentation

Bacteriophages against Streptococcus thermophilus are a growing problem in the Italian cheese industry. One possible control method involves replacing S. thermophilus in mozzarella starter blends with lactic acid bacteria from a different genus or species. In this study, we evaluated lactose-positive pediococci for this application. Because we could not identify any commercially available pediococci with fast acid-producing ability in milk, we transformed Pediococcus pentosaceus ATCC 25744, P. pentosaceus ATCC 25745, and Pediococcus acidilactici ATCC 12697 by electroporation with pPN-1, a 35-kb Lactococcus lactis lactose plasmid. Transformants of P. pentosaceus ATCC 25745 and P. acidilactici ATCC 12697 were then used to examine lactose-positive pediococci for properties related to milk fermentation. Both transformants rapidly produced acid and efficiently retained pPN-1 in lactose broth, and neither bacterium was attacked by bacteriophages in whey collected from commercial cheese facilities. Paired starter combinations of Pediococcus spp. and Lactobacillus helveticus LH100 exhibited synergistic pH reduction in milk, and small-scale cheese trials showed that these cultures could be used to manufacture part-skim mozzarella cheese. Results demonstrate that lactose-positive pediococci have potential as replacement cocci for S. thermophilus in Italian cheese starter blends and may facilitate development of new strain rotation schemes to combat S. thermophilus bacteriophage problems in mozzarella cheese plants.