鼠李糖乳杆菌发酵大豆酸乳工艺优化研究

以大豆为主要原料,将鼠李糖乳杆菌(Lactobacillus rhamnosus)进行活化、驯化与保加利亚乳杆菌(Lactobacillus bulgaricus)和嗜热链球菌(Streptococcus thermophilus)按一定比例混合制备发酵剂,通过单因素实验和正交实验优化确定酸豆乳发酵的生产工艺。结果通过单因素实验确定上述三个菌种按1∶0.5∶1混合作为工作发酵剂;正交实验研究结果表明影响豆乳发酵的显著因素依次为料水比、接种量、发酵时间和蔗糖添加量,最佳条件是:接种量为5%,磨制豆浆料水比为1∶8,蔗糖添加量为8%,在43℃条件下发酵5h,该条件下生产的酸豆乳,具有浓郁的风味和细腻酸甜的口感。      

鼠李糖乳杆菌发酵及冻干保护的研究

对鼠李糖乳杆菌发酵性能和冷冻干燥存活率与保护剂、发酵时间和温度的关系进行了研究。利用液体发酵、紫外分光测量法、微量活菌计数法进行培养、测量。结果表明，鼠李糖乳杆菌发酵周期为12－16h；乳清粉和双歧因子对鼠李糖乳杆菌发酵产酸性能和细菌总数有定的影响。正交实验结果表明，10％乳清粉，15％脱脂奶粉，16h发酵时间的组合，冷冻干燥后存活的影响无显著性差异。结论：乳清粉和双歧因子在发酵后期会对鼠李糖乳杆菌的生长和发酵有促进作用可能是含糖量较高的原因。在冻干时，蛋白质（特别是酪蛋白）对细菌有保护作用。     

鼠李糖乳杆菌乳酸发酵动力学的研究

鼠李糖乳杆菌是一类重要的L-乳酸生产菌,研究其发酵条件及其动力学对发酵工艺及其过程控制具有重要意义.本文针对鼠李糖乳杆菌1.549,通过摇瓶悬浮试验确定其最佳培养条件及发酵培养基组成.在此基础上,研究初始葡萄糖浓度和产物乳酸的积累对发酵过程的影响,建立发酵动力学模型.结果表明,鼠李糖乳杆菌1.549摇瓶发酵最佳培养条件:温度34℃,种龄8 h,接种量5%.由正交试验确定的摇瓶最佳发酵培养基组成:酪蛋白胨15 g/L,酵母膏4 g/L,葡萄糖50 g/L,柠檬酸二铵1 g/L,K2HPO4 2 g,L,乙酸钠2 g/L,MgSO4 0.3g/L,MnSO4·H2O 0.03 g/L,FeSO4·7H2O 0.03 g/L.鼠李糖乳杆菌利用葡萄糖L-乳酸发酵动力学模型结果与本试验结果吻合较好,其乳酸发酵机制属部分生长耦联型.动力学参数揭示,高浓度的初始葡萄糖底物和乳酸的积累对发酵的影响在于其对细胞生长的抑制.     

鼠李糖乳杆菌发酵生产L-乳酸培养基的优化

对鼠李糖乳杆菌发酵生产L-乳酸的发酵培养基组成进行了研究;通过正交实验得到最佳氮源组合为酵母粉5g/L,蛋白胨10g/L,牛肉膏15g/L;生长因子实验表明,番茄汁和白菜汁的添加量各为10%时,L-乳酸的产量最高;葡萄糖、吐温80、生长因子和氮源的四因素正交实验表明,最佳培养基组成为葡萄糖160g/L,酵母粉5g/L,蛋白胨10g/L,牛肉膏15g/L,吐温801mL/L,番茄汁50mL/L,白菜汁50mL/L。用该培养基发酵所得L-乳酸的产量高达143.6g/L,得率为89.8%。      

鼠李糖乳杆菌与嗜热链球菌协同发酵制备酸花生乳研究

本试验以嗜热链球菌(Streptococcus thermophilus,ST)和鼠李糖乳杆菌(Lactobacillus rhamnosus,LGG)协同发酵的酸花生乳为研究对象,以pH、酸度、粘度及活菌数为指标,确定最佳发酵用菌,并通过单因素实验与正交试验确定制备酸花生乳的最佳工艺条件。结果表明,鼠李糖乳杆菌在花生乳中的发酵性能优于保加利亚乳杆菌,并进一步研究鼠李糖乳杆菌与嗜热链球菌协同发酵花生乳的效果,得到最佳发酵工艺为:ST:LGG为2:1,接种量为5 mL/100 mL,发酵时间为4.5 h,蔗糖添加量为6 g/100 mL,此时,pH为4.36,酸度为76 °T,粘度为1532 mPa·s,活菌数为3.62×10¹¹ CFU/mL,感官得分为90,蛋白含量为4.78 g/100 g,可溶性固形物为9.5%,该酸花生乳的色泽为乳白色,香味浓郁,口感适中,组织状态均匀一致,质地细腻。     

重组鼠李糖乳杆菌发酵L-乳酸的初步研究

将自杀质粒pDT转化到鼠李糖乳杆菌JCM 1553中,成功获得了具有四环素抗性的鼠李糖乳杆菌.生长曲线说明,重组菌株能在5 μg/mL四环素MRS培养基中正常生长,最适培养温度为37～42℃.重组菌株在含有10％、15％、20％、25％的葡萄糖发酵培养基中的发酵结果显示:37℃,200 r/min发酵40～88 h,菌体密度OD600最大为29.05;残糖含量最低为0.604％,L-乳酸的最大产量为228.19g/L,葡萄糖转化率最大为96.24％.     

鼠李糖乳杆菌YHOC137及其发酵乳的体外抗致突变作用

乳酸菌及其代谢产物具有优良的生理功能。本文研究了一株产胞外多糖的鼠李糖乳杆菌L.rhamnosusYHOC137对诱变剂的吸附能力,利用艾姆斯实验模型考察了L.rhamnosusYHOC137发酵乳、发酵乳丙酮提取物和产物胞外多糖的体外抗致突变作用。诱变剂吸附实验表明,YHOC137活细胞对2-硝基芴（2-NF）和4-硝基喹啉-N-氧化物（4NQNO）的吸附率分别为38%和55%,YHOC137死细胞对2-NF和4NQNO的吸附分别为25%和50%。YHOC137发酵牛乳能够显著抑制由于2-NF和4NQNO导致的鼠伤寒沙门氏菌的回复突变（P<0.05）,抑制率在38.5%～54.3%之间,L.rhamnosus YHOC137发酵牛乳丙酮提取物对回复突变的抑制率在8.0%～35.3%之间;L.rhamnosus YHOC137胞外多糖对2-NF和4NQNO导致的回复突变的抑制率分别为12.8%和46.0%。      

基因组改组鼠李糖乳杆菌生产L-乳酸发酵培养基的优化

通过单因素试验确定了耐酸性强、高产L- 乳酸的改组菌株Lc-F34 的发酵最适碳源为葡萄糖、初始葡萄糖浓度为90～110g/L,淀粉葡萄糖水解物可以作为乳酸发酵的碳源;最适氮源为酵母抽提物,玉米浆次之,玉米浆可以部分或全部代替酵母抽提物作为乳酸发酵的氮源;适量的MgSO4 和MnSO4 对该菌株的发酵有刺激作用,MgSO4 最适浓度为0.3%,MnSO4 最适浓度为0.05%。     

鼠李糖乳杆菌燕麦益生乳的研制

探讨了以燕麦和脱脂奶粉为主要原料,燕麦经双酶水解所得的糖化液,配以脱脂奶粉,经杀菌冷却,以鼠李糖乳杆菌为发酵剂,接种发酵而成的含有活性成分且具有保健功能的生物乳,它的活性多糖β-葡聚糖量为236mg/L,酸度为108°T,活菌数高达1010cuf/ml。      

鼠李糖乳杆菌及枯草芽孢杆菌发酵对饲料品质的影响

该研究通过测定发酵饲料pH值、活菌数、乳酸含量及中性蛋白酶活性,筛选出适宜基础饲料发酵的鼠李糖乳杆菌（Lactobacillus rhamnosus）BLCC2-0038和枯草芽孢杆菌（Bacillus subtilis）BLCC1-0281,并对筛选出的鼠李糖乳杆菌和枯草芽孢杆菌进行单菌及混菌发酵方式进行了研究。结果表明,BLCC2-0038单独发酵72 h时pH值降至3.73,活菌数达到7.05×109 CFU/g,乳酸含量为48.67 mg/g;BLCC1-0281单独发酵72 h时,活菌数达到2.28×1010 CFU/g,中性蛋白酶活性达到3 207 U/g;BLCC2-0038和BLCC1-0281混菌发酵时,以鼠李糖乳杆菌/枯草芽孢杆菌配比为3∶1,2%接种量,有氧发酵方式最优,发酵72 h时鼠李糖乳杆菌活菌数为5.35×109 CFU/g,枯草芽孢杆菌活菌数为7.80×109 CFU/g,中性蛋白酶活性为1 407.83 U/g。     

Development of a fermented goats' milk containing Lactobacillus rhamnosus: in vivo study of health benefits

BACKGROUND: Lactobacillus rhamnosus CRL1505, a strain of goats' milk origin, is able to stimulate mucosal immunity and protect immunocompetent mice from intestinal and respiratory infections. RESULTS: In this work we developed and characterized a fermented goats' milk containing L. rhamnosus CRL1505, and we demonstrated in a model of immunosuppression in mice that the final dairy product preserves the immunomodulatory properties of the strain. L. rhamnosus CRL1505 survived the manufacturing process of fermented milk and maintained a viability of 10⁶ cfu g^?1 during storage. The fermented goats' milk was accepted by 90.48% of the panelists and was considered as having an acid taste and pleasant aroma. We also demonstrated that the developed product, used as a supplement during the repletion of immunocompromised malnourished mice, was effective in accelerating the recovery of clinical parameters altered by malnutrition and to induce increased resistance against intestinal and respiratory infections. CONCLUSION: Goats' milk fermented with L. rhamnosus CRL1505 could be manufactured as an alternative probiotic dairy product since this new food has the ability to stimulate the common mucosal immune system and to improve defenses against respiratory and intestinal infections. Copyright © 2011 Society of Chemical Industry     

Effect of fermented milk containing Lactobacillus rhamnosus SD11 on oral microbiota of healthy volunteers: A randomized clinical trial

The aims of this study were to evaluate whether short-term consumption of fermented milk containing Lactobacillus rhamnosus SD11 affected levels of oral microbiota in vivo and whether L. rhamnosus SD11 could colonize in the human mouth. We also monitored for potential side effects of the probiotic. The applicability of using L. rhamnosus SD11 compared with Lactobacillus bulgaricus as a starter culture for fermented milk was evaluated. After informed consent, 43 healthy young adults were recruited and randomly assigned to either the probiotic or control group and received fermented milk containing L. rhamnosus SD11 or L. bulgaricus, respectively, once daily for 4 wk. The numbers of mutans streptococci, lactobacilli, and total bacteria in saliva were counted at baseline and then after 4 and 8 wk. An oral examination was performed at baseline and after 8 wk. The persistence of L. rhamnosus SD11 was investigated by DNA fingerprinting using arbitrary primer-PCR. Results demonstrated that statistically significant reductions in mutans streptococci and total bacteria were observed in the probiotic group compared with the control group, and the number of lactobacilli was significantly increased in both groups after receiving fermented milks. Lactobacillus rhamnosus SD11 could be detected (in >80% of subjects) up to 4 wk following cessation of dosing among subjects in the probiotic group. No side effects were reported. Thus, L. rhamnosus SD11 could be used as a starter culture for fermented milk. Daily consumption of L. rhamnosus SD11-containing fermented milk for 4 wk may have beneficial effects on oral health by reducing salivary levels of mutans streptococci. The probiotic was apparently able to colonize the oral cavity for a longer time than previously reported. However, the potential benefits of probiotic L. rhamnosus SD11 on oral health require further evaluation with a larger group of volunteers in a longer-term study.     

鼠李糖乳纤菌YHOC137及其发酵乳的体外抗致突变作用

乳酸菌及其代谢产物具有优良的生理功能.本文研究了一株产胞外多糖的鼠李糖乳杆菌L.rhamnosus YHOC137对诱变剂的吸附能力,利用艾姆斯实验模型考察了L.rhamnosus YHOC137发酵乳、发酵乳丙酮提取物和产物胞外多糖的体外抗致突变作用.诱变剂吸附实验表明,YHOC137活细胞对2-硝基芴(2-NF)和4一硝基喹啉-N-氧化物(4NQNO)的吸附率分别为38%和55%,YHOC137死细胞对2-NF和4NQNO的吸附分别为25%和50%.YHOC137发酵牛乳能够显著抑制由于2-NF和4NQNO导致的鼠伤寒沙门氏菌的回复突变(P＜0.05),抑制率在38.5%～54.3%之间.L.rhamnosus YHOC137发酵牛乳丙酮提取物对回复突变的抑制率在8.0%～35.3%之间;L.rhamnosus YHOC137胞外多糖对2-NF和4NQNO导致的回复突变的抑制率分别为12.8%和46.0%.     

嗜酸乳杆菌发酵乳保藏性的研究

对嗜酸乳杆菌发酵乳在冷藏条件下保藏性进行了研究. 结果表明, 7 ℃条件下 14 d两株嗜酸乳杆菌发酵乳中细菌的存活率分别为 3.43% 和 2.20%, 且活菌数仍在 108 mL 1以上, 酸度为 90 ° T和 107 ° T, 双乙酰分别增加了 11.80% 和 56.41%, 乙醛含量分别为 2.993 mmol/ mL和 2.561 mmol/ mL, 使发酵乳具有良好风味.     

The nutrient requirements of Lactobacillus rhamnosus GG and their application to fermented milk

Lactobacillus rhamnosus GG (LGG) performs many physiological functions, but the fermentation time is long when fermented milk is prepared using LGG alone. To shorten the fermentation time, we analyzed the nutrient requirement profiles of LGG. Based on nutrient requirement profiles, we evaluated the effects on the fermentation time, quality, and sensory properties of unmodified cow's milk fermented by LGG alone. According to the consumption and necessary patterns of amino acids and those of purine, pyrimidine, vitamins, metal ions, and nutrients essential to LGG, we selected Cys, Ser, Arg, Pro, Asp, Glu, guanine, uracil, and xanthine with which to supplement milk. Compared with fermented milk prepared using LGG alone in unmodified milk, the fermentation time of supplemented milk was shortened by 5 h. Viable cell counts, titratable acidity, and water-retaining capability of the fermented milk were improved by addition of nutrient supplements. Supplementation with nutrients did not obviously change the sensory and textural characteristics of fermented milk.     

Dry sausage fermented by Lactobacillus rhamnosus strains

The ability of three probiotic Lactobacillus rhamnosus strains GG, E-97800 and LC-705 and one commercial Pediococcus pentosaceus starter strain (control) to produce dry sausage was studied. During the fermentation process the numbers of inoculated lactic acid bacteria increased from approx. 7 log10 to 8-9 log10 cfu/g and the pH values decreased from 5.6 to 4.9-5.0. The sensory test indicated that the dry sausages fermented by L. rhamnosus LC-705 were inferior to the control sausages. The presence of inoculated experimental strains as predominant organisms in the dry sausages was recognised on the basis of their genetic fingerprints by ribotyping. The concentrations of biogenic amines remained low during the ripening process. These results indicated that the studied Lactobacillus rhamnosus strains, especially strains GG and E-97800, are suitable for use as probiotic starter cultures in fermenting dry sausage.     

Beneficial effects of Lactobacillus rhamnosus hsryfm 1301 fermented milk on rats with nonalcoholic fatty liver disease

A growing stream of research suggests that probiotic fermented milk has a good effect on nonalcoholic fatty liver disease. This work aimed to study the beneficial effects of Lactobacillus rhamnosus hsryfm 1301 fermented milk (fermented milk) on rats with nonalcoholic fatty liver disease induced by a high-fat diet. The results showed that the body weight and the serum levels of total cholesterol, total glyceride, low-density lipoprotein, alanine transaminase, aspartate aminotransferase, free fatty acid, and reactive oxygen species were significantly increased in rats fed a high-fat diet (M) for 8 wk, whereas high-density lipoprotein cholesterol and superoxide dismutase were significantly decreased. However, the body weight and the serum levels of total cholesterol, total glyceride, alanine transaminase, aspartate aminotransferase, free fatty acid, reactive oxygen species, interleukin-8, tumor necrosis factor-α, and interleukin-6 were significantly decreased with fermented milk (T) for 8 wk, and the number of fat vacuoles in hepatocytes was lower than that in the M group. There were significant differences in 19 metabolites in serum between the M group and the C group (administration of nonfermented milk) and in 17 metabolites between the T group and the M group. The contents of 7 different metabolites, glycine, glycerophosphocholine, 1,2-dioleoyl-sn-glycero-3-phosphocholine, thioetheramide-PC, d-aspartic acid, oleic acid, and l-glutamate, were significantly increased in the M group rat serum, and l-palmitoyl carnitine, N6-methyl-l-lysine, thymine, and 2-oxadipic acid were significantly decreased. In the T group rat serum, the contents of 8 different metabolites—1-O-(cis-9-octadecenyl)-2-O-acetyl-sn-glycero-3-phosphocholine, acetylcarnitine, glycine, glycerophosphocholine, 1,2-dioleoyl-sn-glycero-3-phosphocholine, d-aspartic acid, oleic acid, and l-glutamate were significantly decreased, whereas creatinine and thymine were significantly increased. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that 50 metabolic pathways were enriched in the M/C group and T/M group rat serum, of which 12 metabolic pathways were significantly different, mainly distributed in lipid metabolism, amino acid, and endocrine system metabolic pathways. Fermented milk ameliorated inflammation, oxygenation, and hepatocyte injury by regulating lipid metabolism, amino acid metabolic pathways, and related metabolites in the serum of rats with nonalcoholic fatty liver disease.     

嗜酸乳杆菌在现代乳品中的应用研究进展

分析了现代乳品生产状况及存在问题，概述了嗜酸乳杆菌生物学特性、生理功能以及在乳品工业上的应用及发展趋势。     

Use of homogenisation pressure to improve quality and functionality of probiotic fermented milks containing Lactobacillus rhamnosus BFE 5264

The effects of 60‐MPa milk homogenisation treatment were investigated on the viability of the probiotic strain Lactobacillus rhamnosus BFE5264, when used as yoghurt co‐starter, as well as on the aroma profile, texture and microstructure of the resulting set‐type fermented milks. The results demonstrated that the combined use of homogenisation pressure and co‐inoculation of the probiotic strain with the traditional yoghurt starters allowed the reduction in the product coagulation time, the increase of the probiotic strain viability and the improvement of the product volatile molecule profiles. The rheological indices and the microstructure results indicated the positive effects of the milk homogenisation treatment on the product viscosity index and exopolysaccharide production.