双歧杆菌在发酵乳中活性的研究

分别使用两歧双歧杆菌和长双岐杆菌制作酸乳并冷藏21d,应用AMC,RMS培养基检测样品的双歧杆菌活菌数。发酵乳中的双歧杆菌的浓度达到10^8-10^9CFU/mL,在21d的冷藏中二种双歧杆菌的活菌数都超过了最小保健剂量10^6CFU/mL。RMS培养基同样有效地分离两歧双歧双歧杆菌和长双歧杆菌,可以采用涂布法和倾注法进行操作,RMS是对酸乳中双歧杆菌计数的最适宜的选择性培养基,使用AMC培养基由于涂布法造成较低的活菌计数。     

酸奶中嗜酸乳杆菌和植物乳杆菌检测方法的研究

根据嗜酸乳杆菌、植物乳杆菌、嗜热链球菌和保加利亚乳杆菌对不同碳水化合物的选择性利用，设计了适合上述4种乳酸菌的选择性计数培养基，并对其效果进行了验证。结果表明，利用MRS培养基、麦芽糖-MRS培养基和山梨醇-MRS培养基(两种培养基共同使用)能满足选择性计数的要求。以所设计的选择性培养基，研究了含有4种乳酸菌的酸奶中不同乳酸菌在产品货架期内活菌数的变化规律。     

酸奶中益生菌的选择性计数的研究

对多菌种保健酸奶中各微生物的选择性计数方法进行了研究。利用非选择性培养基MRS-1和组分成分较简单的MGLP、MGLP-1两种选择性培养基,在37℃或15℃,厌氧或微好氧条件下对三种多菌种保健酸奶中保加利亚乳杆菌、干酪乳杆菌、嗜酸乳杆菌、双歧杆菌进行了选择性计数,方法简便易行。该方法可用于市售的其他类型的多菌种保健酸奶中特征性微生物的测定。     

可用于保健食品的益生菌菌种

两歧双歧杆菌、婴儿双岐杆菌、长双歧杆菌、短双岐杆菌、青春双歧杆菌、保加利亚乳杆菌、嗜酸乳杆菌、干酪乳杆菌干酪亚种、嗜热链球菌。     

双岐杆菌酸奶的研制

就双歧杆菌以脱脂牛乳为培养基的耐氧发酵条件进行了探索,试验了导致双歧杆菌耐氧增殖的几种促进剂,且获得产菌量较高的发酵培养基,并将此菌应用于发酵乳制品。经试验确定了最佳发酵工艺,使用BAT混合菌种,或者将婴儿双歧杆菌、嗜酸乳杆菌、嗜热链球菌分别单独培养后按不同比例混合培养制备工作发酵剂,然后就可在常规条件下生产出双歧杆菌、嗜酸乳杆菌的活菌个数均高达10~(7~8)/ml以上、风味与普通酸乳相似、营养保健价值远高于普通酸乳的双歧杆菌酸奶。     

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)。     

植物乳杆菌FCJX 102和嗜酸乳杆菌FCJX 104共发酵山楂-葛根汁产乙醛脱氢酶

从短乳杆菌、副干酪乳杆菌、植物乳杆菌、嗜酸乳杆菌、鼠李糖乳杆菌等乳酸菌中筛选出产乙醛脱氢酶的植物乳杆菌Lactobacillus plantarum FCJX 102和嗜酸乳杆菌Lactobacillus acidophilu FCJX 104。在单因素实验的基础上,以山楂葛根比、菌种比、发酵时间为影响因子,对产乙醛脱氢酶发酵条件进行正交实验优化。优化后在培养基中山楂葛根质量比为1∶2,菌种L.plantarum FCJX 102与L.acidophilu FCJX 104比为2∶1时,在37℃下培养16 h,获得的乙醛脱氢酶活力最高可达16.083 U/g。     

温度对嗜酸乳杆菌和干酪乳杆菌发酵羊奶的影响

以鲜羊奶为原料,保加利亚乳杆菌和嗜热乳链球菌为基础发酵剂,在此基础上分别添加嗜酸乳杆菌和干酪乳杆菌,研究温度对两菌株发酵羊奶过程中酸度、pH、活菌数及总活茵数的影响.结果表明:嗜酸乳杆菌酸羊奶的最佳发酵温度为37℃,此时凝乳时间为4h,酸度、pH、嗜酸乳杆菌数和总活菌数分别为97.8 0T、3.88、1.8×107 CFU/mL和1.38×109 CFU/mI,感官评价总分可达到8.35分;干酪乳杆菌羊奶的最佳发酵温度为39℃,此时酸羊奶凝固时间为4.5h,酸度、pH、干酪乳杆菌数和总茵数分别为79.2 °T、4.48、1.56×108 CFU/mL和1.81×109 CFU/mL,感官评价总分可达到7.00分.     

发酵乳中乳酸菌的选择性计数及分离鉴定

发酵乳产品的菌种组成与活菌数的含量是产品质量的关键。该文通过选择性培养基、基质辅助激光解吸电离飞行时间质谱(matrix-assisted laser desorption/ionization time of flight mass spectrometry, MALDI-TOF-MS)快速鉴定技术及多相鉴定技术探究3种发酵乳中乳酸菌的活菌数及种类。研究结果表明,3种发酵乳产品中,GB 4789.35对乳酸菌总数的计数结果均高于选择性培养基,M17培养基对嗜热链球菌的计数结果均高MC培养基。MALDI-TOF MS快速鉴定表明M17、MRS(含50μg/mL的万古霉素)、双歧杆菌培养基可以选择性的分离发酵乳中的嗜热链球菌(Streptococcus thermophilus)、干酪乳酪杆菌(Lacticaseibacillus casei)和双歧杆菌(Bifidobacterium spp.),酸化MRS培养基对德氏乳杆菌(Lactobacillus delbrueckii)的选择性较差,不能在含有双歧杆菌的发酵乳中选择性分离德氏乳杆菌。进一步通过多相鉴定确定3种发酵乳产品中乳酸菌在...     

乳制品中选择性分离与计数植物乳杆菌的方法

根据乳酸菌对抗生素的敏感性、产酸能力和碳源利用不同,研制出植物乳杆菌分离计数培养基(LPMRS培养基),通过对9种不同的乳酸菌菌株单独试验及混合试验,对该培养基的特异性进行了评价。通过对LP-MRS培养基和MRS培养基中植物乳杆菌计数比较,对该培养基是否抑制植物乳杆菌生长进行了验证。结果表明,该培养基可抑制乳酸乳球菌乳酸亚种、嗜热链球菌、瑞氏乳杆菌、嗜酸链球菌、婴儿双歧杆菌的生长,并能将植物乳杆菌从干酪乳杆菌群分离开来,且对植物乳杆菌无抑制作用。该方法操作简便,成本低,可广泛应用于乳制品中植物乳杆菌的分离和计数。     

Selective enumeration of Lactobacillus delbrueckii ssp. bulgaricus,Streptococcus thermophilus,Lactobacillus acidophilus,bifidobacteria, Lactobacillus casei,Lactobacillus rhamnosus,and propionibacteria

Nineteen bacteriological media were evaluated to assess their suitability to selectively enumerate Lactobacillus delbrueckii ssp. bulgaricus, Streptococcus thermophilus, Lactobacillus casei, Lactobacillus rhamnosus, Lactobacillus acidophilus, bifidobacteria, and propionibacteria. Bacteriological media evaluated included Streptococcus thermophilus agar, pH modified MRS agar, MRS-vancomycine agar, MRS-bile agar, MRS-NaCl agar, MRS-lithium chloride agar, MRS-NNLP (nalidixic acid, neomycin sulfate, lithium chloride and paramomycine sulfate) agar, reinforced clostridial agar, sugar-based (such as maltose, galactose, sorbitol, manitol, esculin) media, sodium lactate agar, arabinose agar, raffinose agar, xylose agar, and L. casei agar. Incubations were carried out under aerobic and anaerobic conditions at 27, 30, 37, 43, and 45 degrees C for 24, 72 h, and 7 to 9 d. S. thermophilus agar and aerobic incubation at 37 degrees C for 24 h were suitable for S. thermophilus. L. delbrueckii ssp. bulgaricus could be enumerated using MRS agar (pH 4.58 or pH 5.20) and under anaerobic incubation at 45 degrees C for 72 h. MRS-vancomycine agar and anaerobic incubation at 43 degrees C for 72 h were suitable to enumerate L. rhamnosus. MRS-vancomycine agar and anaerobic incubation at 37 degrees C for 72 h were selective for L. casei. To estimate the counts of L. casei by subtraction method, counts of L. rhamnosus on MRS-vancomycine agar at 43 degrees C for 72 h under anaerobic incubation could be subtracted from total counts of L. casei and L. rhamnosus enumerated on MRS-vancomycine agar at 37 degrees C for 72 h under anaerobic incubation. L. acidophilus could be enumerated using MRS-agar at 43 degrees C for 72 h or Basal agar-maltose agar at 43 degrees C for 72 h or BA-sorbitol agar at 37 degrees C for 72 h, under anaerobic incubation. Bifidobacteria could be enumerated on MRS-NNLP agar under anaerobic incubation at 37 degrees C for 72 h. Propionibacteria could be enumerated on sodium lactate agar under anaerobic incubation at 30 degrees C for 7 to 9 d. A subtraction method was most suitable for counting propionibacteria in the presence of other lactic acid bacteria from a product. For this method, counts of lactic bacteria at d 3 on sodium lactate agar under anaerobic incubation at 30 degrees C were subtracted from counts at d 7 of lactic bacteria and propionibacteria.     

混合制剂中快速计数双歧杆菌鉴别培养基的研究

研制了一种混合制剂中快速计数双歧杆菌鉴别培养基。用添加X-Gal的改良MRS培养基和厌氧胶法对4种标准双歧杆菌(长双歧杆菌、短双歧杆菌、青春双歧杆菌、两歧双歧杆菌)和2种标准乳酸菌(保加利亚乳杆菌、嗜热链球菌)分别单独培养、混合培养,结果在X-Gal培养基上,双歧杆菌单独培养及与乳酸菌混合培养双歧杆菌均为白色菌落或浅蓝色菌落,而乳酸菌为蓝色菌落。结果表明,在X-Gal培养基上双歧杆菌和乳酸菌有明显的鉴别性,可用于双歧杆菌和乳酸菌混合制剂的菌落鉴别计数。     

Viability During Storage of Selected Probiotic Lactobacilli and Bifidobacteria in a Yogurt-like Product

ABSTRACT: Multiple species cultures, including 2 strains of Streptococcus thermophilus and Lactobacillus acidophilus NCFM plus 1 strain each of Bifidobacterium longum and Lactobacillus casei , were used to make yogurt-like products. The lactobacilli and bifidobacteria were tested for growth in the products and subsequent viability during refrigerated storage. During fermentation, L. casei Com-5 actually declined in numbers, while L. casei E5 and E10 increased about 2 fold. Numbers of B. longum S9 increased about 3 fold while B. longum Com-4 did not increase. During storage, L. acidophilus NCFM appeared stable in all mixtures and both strains of bifidobacteria decreased. Lactobacillus casei E5 and E10 were more stable than was L. casei Com-5.     

眉山泡菜中乳酸菌的分离鉴定

目的：分析眉山泡菜的基本数据和乳酸菌的菌种构成。方法：从眉山市采集泡菜12 份,测定pH值、总酸度、盐度、乳酸菌计数,用16S rRNA序列分析法鉴定菌种。结果：样品pH值的范围是3.37～3.89,总酸度的范围是0.65～0.92 g/100 g（以乳酸计）,盐度的范围是4.16%～5.28%（以NaCl计）,MRS和M17乳酸菌计数分别是1.71～6.33、1.33～5.78（lg（CFU/g））。总酸度对乳酸菌计数影响最大。共分离鉴定出16 株乳酸菌：Lactobacillus fermentum（2 株）、Lactobacillus plantarum（3 株）、Lactobacillus brevis（2 株）、Lactobacillusacidophilus（1 株）、Lactobacillus casei（1 株）、Lactobacillus pentosus（1 株）、Lactobacillus delbrueckii（1 株）、Lactococcus lactis（3 株）、Pediococcus pentosaceus（2 株）。结论：眉山泡菜中乳酸菌存在多样性,实验结果为工业发酵生产泡菜积累了菌株。     

Incorporation of citrus fibers in fermented milk containing probiotic bacteria

The incorporation of Lactobacillus acidophilus CECT 903, Lactobacillus casei CECT 475 and Bifidobacterium bifidum CECT 870 together with lemon (LF) and orange (OF) fibers obtained from juice by-products were tested in (i) a model system: fiber enriched with de Man Rogosa Sharp (MRS) broth cultured with each probiotic bacteria and (ii) evaluation of populations of probiotic bacteria in fermented milks formulated with citrus fibers. Citrus fibers enhanced L. acidophilus CECT 903, and L. casei CECT 475 survival in MRS during refrigerated storage, whereas erratic results were obtained for B. bifidum CECT 870, OF enhanced its growth and LF had inhibitory effect. Populations of probiotic bacteria decreased with storage time in MRS broth. The presence of yogurt starter bacteria in probiotic fermented milks favored the growth and survival of L. acidophilus and B. bifidum. Citrus fiber presence in fermented milks also enhanced bacterial growth and survival of the tested probiotic bacteria. This study indicates that citrus fiber enriched fermented milk have good acceptability and are good vehicles for a variety of commercial probiotics but survival of B. bifidum will need to be improved.     

不同乳酸菌在冬瓜汁中的发酵特性研究

向鲜榨并经巴氏灭菌的冬瓜汁中接入不同的乳酸菌(干酪乳杆菌、嗜热链球菌、植物乳杆菌、嗜酸乳杆菌、鼠李糖乳杆菌、双歧杆菌和保加利亚乳杆菌)进行发酵,比较发酵过程中乳酸菌活菌数、pH值、可滴定酸、总糖、还原糖、总多酚和色泽等变化和发酵后挥发性风味物质种类与相对含量。结果表明,冬瓜汁营养丰富,上述各种乳酸菌均能在冬瓜汁中很好地生长,其中干酪乳杆菌的生长速率(对数生长期)略低于其他6种菌;另外,七种乳酸菌发酵后冬瓜汁中主要挥发性风味物质主要有酸类、醇类、酯类、醛类、酮类五类,保加利亚乳杆菌发酵的冬瓜汁中检出的挥发性风味物质最多。除双歧杆菌之外其他六种乳酸菌发酵的冬瓜汁理化性质差别不大,双歧杆菌发酵的冬瓜汁在总色差上明显高于其他乳酸菌,且双歧杆菌的产酸能力最强,在发酵期间其可滴定酸含量最高。     

Isolation and identification of lactobacilli from novel-type probiotic and mild yoghurts and their stability during refrigerated storage.

A total of 26 Lactobacillus strains were isolated from various mild yoghurts and novel-type probiotic dairy products and from a starter culture preparation and were identified by using DNA-DNA hybridization technique. The species present in those products were found to be Lactobacillus acidophilus, L. johnsonii, L. crispatus, L. casei, L. paracasei and L. rhamnosus. DNA homology analysis revealed that some strains had been misclassified by their investigators. Three strains designated as L. acidophilus (L. acidophilus LA-1, L. acidophilus ATCC 43121 and the Lactobacillus strain from Biogarde culture) were found to belong to L. johnsonii and L. acidophilus L1 to be L. crispatus. Strains designated as L. casei were found to be members of three separate species: L. casei, L. paracasei and L. rhamnosus. Viable numbers of lactobacilli in mild and probiotic yoghurts varied greatly including some products with very low Lactobacillus counts. The majority of the probiotic yoghurts, however, contained viable counts above 10(5) per g even at the end of the best before use period.     

Effect of lactulose on biotransformation of isoflavone glycosides to aglycones in soymilk by lactobacilli

ABSTRACT:  Lactobacillus acidophilus 4461, L. acidophilus 4962, L. casei 290, and L. casei 2607 were used to hydrolyze isoflavone glycosides (IG) to biologically active forms—isoflavone aglycones (IA)—in soymilk (SM) prepared from soy protein isolate (SPI) and soymilk supplemented with 0.5% (w/v) of lactulose (SML). L. acidophilus 4461 utilized the highest level of lactulose (3.01 mg/mL) and L. acidophilus 4962 utilized the least (0.86 mg/mL) at 24 h of incubation. The pH values decreased to 4.00 to 5.00 in SML, while they remained relatively high (6.15 to 6.36) in SM. Supplementation with lactulose significantly ( P < 0.05) enhanced the viable counts of all the 4 Lactobacillus strains. At the end of incubation, the viable counts of Lactobacillus ranged from 8.08 to 8.25 log CFU/mL in SML compared to 6.99 to 7.11 log CFU/mL in SM. Supplementation with lactulose increased the biotransformation of IG to IA after 6 h of incubation. The presence of lactulose in the medium enhanced the biotransformation level of IG to IA by Lactobacillus up to 21.9%. The hydrolysis level of malonyl genistin and acetyl genistin in SML was much higher than in SM by all the 4 probiotic organisms. The biotransformation of IG to IA occurred rapidly during the 1st 12 h of incubation in both SML and SM. Among the 4 Lactobacillus strains, L. acidophilus 4461 biotransformed the highest level (88.8%) of IG to IA in SML compared to 68.2% in SM after 24 h of incubation.     

菊粉寡糖促进嗜酸乳杆菌生长的研究

对菊粉可促进嗜酸乳杆菌的生长进行了初步研究。结果表明 ,用菊粉代替培养基中部分葡萄糖 ,嗜酸乳杆菌的生长得到明显的促进 ,当MRS培养基中葡萄糖与菊粉的质量比为 1∶1时 ,嗜酸乳杆菌的生物量及酸度得到提高 ,在 3 7℃下培养 48h ,活菌的数量及酸度比对照组分别提高 1 0 10CFU/mL和 1 0°T。     

干酪乳杆菌SB27降低N-亚硝胺对IEC-6细胞毒性作用研究

该研究选用具有益生功能的干酪乳杆菌（Lactobacillus casei）SB27为研究对象,采用菌落计数法分析N-亚硝胺（N-二甲基亚硝胺（NDMA）、N-二乙基亚硝胺（NDEA）、N-亚硝基吡咯烷（NPYR）和N-亚硝基哌啶（NPIP）（0～80 μg/mL）在MRS液体培养基中对干酪乳杆菌SB27生长的影响,并以维生素C（VC）（50 μmol/L）为阳性对照,采用细胞计数试剂盒（CCK）-8法分析干酪乳杆菌SB27（103～106 CFU/mL）降低N-亚硝胺对大鼠肠道黏膜细胞IEC-6毒性的损伤。结果表明,N-亚硝胺在MRS液体培养基中对干酪乳杆菌SB27的生长增殖无显著影响（P＞0.05）。干酪乳杆菌SB27可降低NDMA、NDEA、NPYR及NPIP对大鼠肠道黏膜细胞IEC-6的毒性损伤。