短乳杆菌与植物乳杆菌的发酵特性

【背景】目前对于酸菜发酵的研究主要关注点是植物乳杆菌(Lactobacillus plantarum),有关短乳杆菌(Lactobacillus brevis)在酸菜方面的研究报道很少。【目的】为了挖掘短乳杆菌的发酵性能并开发酸菜发酵剂,将2株短乳杆菌分别与1株植物乳杆菌进行组合并发酵酸菜,分析短乳杆菌对酸菜发酵品质的影响。【方法】分别测定短乳杆菌与植物乳杆菌的单菌株生长产酸性能、耐酸性及亚硝酸盐降解力,并将两菌种组合后发酵酸菜,分析1-7d内酸度、乳酸菌活菌数、亚硝酸盐含量及酸菜质构特性的变化趋势。【结果】相较于短乳杆菌Lb-9-2,短乳杆菌Lb-5-3的生长和产酸速率较慢、酸耐受力较弱,但其亚硝酸盐降解力较强。两株短乳杆菌分别与植物乳杆菌Lp-9-1组合后产酸力显著增强,并在3 d时达到最低pH值(约3.10);植物乳杆菌Lp-9-1的添加使酸菜中总体乳酸菌生长延迟,在5 d时达到最高活菌数;组合菌种的样品中亚硝酸盐含量在1-7 d内变化较为平缓,前5天内两个组合之间差异不显著;接种乳酸菌会降低酸菜硬度和弹性,发酵3d时Lb-5-3/Lp-9-1组合的硬度最大,感官评价得分最高。【...     

不同发酵条件对乳杆菌O-2菌株代谢产物的影响

目的:研究乳杆菌(Lactobacillus acidophilus sp.)O-2菌株生长和积累类细菌素所需的营养和温度条件.方法:采用分段控温发酵法,即在发酵后期,改变温度继续发酵;以发酵液抑菌圈直径为指标对发酵的营养和温度条件进行筛选.结果:后期32 ℃控温发酵有利于类细菌素积累,优化后的4号配方,发酵液菌数高达8.2×1010个/ml(细菌计数器法),抑菌圈直径最大,达到8.8 mm.结论:利用4号配方进行分段控温发酵能有效地促进O-2菌株的生长繁殖和积累类细菌素.     

高糖和氮源对鼠李糖乳杆菌(Lactobacillus rhamnosus)L-乳酸发酵的影响

鼠李糖乳杆菌经实验室耐高糖高酸选育,能够在高糖浓度下高效高产L-乳酸。以酵母粉为氮源和生长因子,葡萄糖初始浓度分别为120 g/L和146 g/L,摇瓶培养120h,L-乳酸产量分别为104g/L和117.5g/L,L-乳酸得率分别为86.7%和80.5%。高葡萄糖浓度对菌的生长和乳酸发酵有一定的抑制。增加接种量,在高糖浓度发酵条件下,可以缩短发酵时间,但对增加乳酸产量效果不明显。乳酸浓度对鼠李糖乳杆菌生长和产酸有显著的影响。初始乳酸浓度到达70g/L以上时,鼠李糖乳杆菌基本不生长和产酸,葡萄糖消耗也被抑制。酵母粉是鼠李糖乳杆菌的优良氮源,使用其它被测试的氮源菌体生长和产酸都有一定程度的下降。用廉价的黄豆粉并补充微量维生素液,替代培养基中的酵母粉,可以使产酸浓度和碳源得率得以基本维持。     

植物乳杆菌Lp-2的高密度发酵

高密度培养植物乳杆菌是制作其发酵剂的重要环节。首先,研究了不同的溶氧和pH对植物乳杆菌的分批发酵的影响。在分批发酵的基础上,为进一步提高发酵液中的菌体浓度,进行了补料分批发酵实验。最终通过对蔗糖反馈补料发酵试验对比改造获得了pH反馈补料发酵工艺。此发酵补料工艺可以控制蔗糖残糖量始终处于较低的水平,因此获得了最高的菌体产量。菌体干重达到13.56g/L,较分批培养提高90.05%。     

鼠李糖乳杆菌LV108及其发酵乳免疫调节作用的比较

目的 探讨鼠李糖乳杆菌LV108及其发酵乳对免疫抑制小鼠免疫功能的调节作用。 方法 将BALB/c小鼠随机分为5组,每组10只,即空白组(正常小鼠)、模型组(免疫抑制小鼠)、药物组(免疫抑制小鼠食物中添加左旋咪唑)、LV108菌悬液组(免疫抑制小鼠食物中添加LV108菌悬液)和LV108发酵乳组(免疫抑制小鼠食物中添加LV108发酵乳),除空白组外其余组构建免疫抑制小鼠模型。干预4周后,分别测定各组小鼠体质量和脏器指数,血清中白细胞介素2(IL2)、肿瘤坏死因子α(TNFα)和免疫球蛋白G(IgG)含量,血清溶血素含量、耳肿胀度和肝、脾巨噬细胞吞噬能力。 结果 相比模型组,LV108菌悬液组和LV108发酵乳组小鼠体质量增长速度、脏器指数、血清IL2与IgG水平、血清溶血值、耳肿胀度和巨噬细胞吞噬能力显著升高(均P结论 LV108菌体及发酵乳对免疫抑制小鼠具备较全面的免疫调节作用,均可提高小鼠的自身免疫力;LV108发酵乳对小鼠的免疫调节作用强于LV108菌体。     

植物乳杆菌发酵、冻干工艺及其益生特性的研究

目的 以Lactobacillus plantarum SQ-2506为目标,研究该菌株的发酵、冻干工艺及其益生特性。方法 通过对培养基中C源、N源和刺激因子的浓度改变考察对活菌数的影响,从而确定培养基的最佳配方;在确定最佳培养基后做出该菌的生长曲线以确定最佳发酵时间点;同时考察冻干保护剂的配方和预冷时间对菌粉活菌数的影响;此外,对植物乳杆菌进行产酸、产H2O2、生物膜形成能力、抑菌特性以及抗氧化能力的检测。结果 最佳MRS培养基中葡萄糖浓度为0.8%、酪蛋白胨为0.4%、牛肉粉为0.6%、吐温为0.06%;植物乳杆菌的生长曲线在5 h时达到稳定期,此时发酵液活菌数为3.16×109 CFU/mL,发酵液的pH为4.45。最佳冻干保护剂的配方：脱脂乳100 g/L,蔗糖120 g/L,抗坏血酸20 g/L,谷氨酸钠30 g/L;冻干前对上机液预冻时间为2 h,此时菌粉冻干存活率为70.21%。该菌株具有产酸、产H2O 2能力,并对大肠埃希菌、金黄色葡萄球菌和白色假丝酵母均有一定的抑制作用,形成膜能力较强,且具有一定的抗氧化能力。结论 通过培养基成分、发酵条件和冻干工艺的优化以及对其益生特性的研究,为下一步新药开发和规模化生产奠定基础。     

对德氏乳杆菌DM8909菌株的发酵工艺研究

德氏乳杆菌 DM890 9菌株是大连医科大学微生态学研究所分离驯化的一株兼性厌氧菌 ,主要用于防治非特异性阴道炎等妇科疾病。本实验通过对德氏乳杆菌 DM890 9菌株进行摇瓶、小型全自动发酵罐和 5 0 0 L发酵罐发酵工艺学研究 ,考察其发酵工艺中试条件。现将研究结果报告如下 :1　材料与方法1.1　菌种　本研究所使用的菌种德氏乳杆菌 DM890 9(L actobacillus debrueckii subsp.lactis)由大连医科大学微生态学研究所提供。1.2　培养基　摇瓶种子培养基、小罐发酵培养基及大罐发酵培养基均采用 L BS培养基。1.3　培养方法1.3.1　摇瓶培养　…     

发酵中含氮类原料对保加利亚乳杆菌活菌数的影响

目的研究生产发酵过程中培养基含氮原料与发酵的相关性。方法实验通过对不同生产厂家三种原料进行理化指标检测,并通过正交试验,比较不同原料发酵后保加利亚乳杆菌发酵液活菌数。结果最佳条件为酪蛋白胨氨基氮含量高,酵母浸粉的炽灼残渣低,牛肉粉总氮含量高。结论经过相同原料不同生产厂家的配方发酵后的发酵液活菌数存在差异,其理化指标对发酵有一定影响。     

一株乳杆菌对蒸汽爆破处理纤维物料的乳酸发酵研究

用筛选得到的一株乳酸杆菌ZJU-1(Lactobacillus sp．)对蒸汽爆破预处理纤维物料的乳酸发酵进行了研究,结果表明该菌株能对蒸汽爆破处理的纤维物料酶解液进行乳酸发酵,在还原糖质量浓度为52．1mg/mL时,乳酸量为42．1mg/mL;与纤维素酶的酶解过程相耦合,对蒸汽爆破处理的物料进行同时糖化乳酸发酵。其发酵周期比分步糖化发酵的过程周期短,在底物质量分数为80mg/mL,接种量为10％,温度为45％时,乳酸量为45．3mg/mL。     

弱后酸化瑞士乳杆菌的筛选及发酵特性研究

[目的]在大健康背景下,发酵乳凭借其优良的营养和保健功能备受青睐.后酸化是发酵乳在贮存、运输和销售等过程中活性乳酸菌继续代谢产酸导致的,严重影响产品的感官品质,降低菌株的存活率.本文通过筛选弱后酸化的瑞士乳杆菌,改善发酵乳的后酸化问题.[方法]本研究以瑞士乳杆菌L551为出发菌株,硫酸新霉素为筛选压力,筛选弱后酸化的瑞...     

Administration of Lactobacillus fermentum CRL1446 increases intestinal feruloyl esterase activity in mice

Aims: To evaluate the effect of oral administration of Lactobacillus fermentum CRL1446 on the intestinal feruloyl esterase (FE) activity and oxidative status of mice. Methods and Results: Adult Swiss albino mice received Lact. fermentum CRL1446 at the doses 10⁷ and 10⁹ cells per day per mouse for 2, 5, 7 and 10 days. Intestinal FE activity, intestinal microbiota counts, plasmatic thiobarbituric acid‐reactive substances (TBARS) percentage and glutathione reductase (GR) activity were determined. Mice that received Lact. fermentum CRL1446 at the dose 10⁷ cells per day for 7 days showed a twofold increase in total intestinal FE activity, compared to the nontreated group. In large intestine content, FE activity increased up to 6·4 times. No major quantitative changes in colonic microbiota were observed in treated animals. Administration of this strain produced an approx. 30–40% decrease in the basal levels of plasmatic TBARS and an approx. twofold increase in GR activity from day 5 of feeding with both doses. Conclusions: Oral administration of Lact. fermentum CRL1446 to mice increases total intestinal FE activity, decreases the basal percentage of plasmatic lipoperoxides and increases GR activity. Significance and Impact of the Study: Lactobacillus fermentum CRL1446 could be orally administered as a dietary supplement or functional food for increasing the intestinal FE activity to enhance the bioavailability of ferulic acid, thus improving oxidative status.     

罗伊乳杆菌对小鼠血清细胞因子含量和肠道菌群的影响

目的 探讨罗伊乳杆菌对小鼠免疫力及肠道菌群的影响。方法 将50只昆明系小鼠按体重随机分成5组：空白对照组、低剂量组、中剂量组、高剂量组和发酵上清液组。空白对照组灌胃等量生理盐水,其余各组分别灌胃罗伊乳杆菌菌液及发酵液上清21 d后,眼球取血收集血清,采用ELISA法检测IL-2、IFN-γ、IgA和IgG含量;采用16S rRNA基因高通量测序分析小鼠肠道菌群变化。结果 与对照组相比,其余各组小鼠血清IL-2、IFN-γ、IgA和IgG的水平均明显升高,粪便菌群丰度有所增高,多样性降低。与对照组相比,低剂量组和中剂量组小鼠粪便菌群结构无显著差异,而高剂量组和发酵上清液组小鼠粪便菌群结构差异显著。结论 罗伊乳杆菌可以增强小鼠免疫力,提高菌群丰度,改变小鼠肠道菌群结构。     

Free radical scavenging activity of Lactobacillus fermentum in vitro and its antioxidative effect on growing–finishing pigs

Aims:  To evaluate the free radical-scavenging capacity of Lactobacillus fermentum and its effects on antioxidant enzyme levels in finishing pigs.
Methods and Results:  The free radical-scavenging activity of Lact. fermentum was analysed in vitro . The tested Lactobacillus showed a high scavenging ability against DPPH (1,1-diphenyl-2-picrylhydrazyl), superoxide and hydroxyl radicals which was dose dependent. Subsequently, 108 crossbred pigs weighing 20·67 BW, were allotted to dietary treatments including a basal diet or the basal diet supplemented with either aureomycin or 10·2 × 10⁷  Lact. fermentum CFU g⁻¹ diet. Supplementation of Lact. fermentum increased total antioxidant capacity ( P  < 0·01) in serum from 50 kg pigs, while serum superoxide dismutase ( P  = 0·01) and glutathione peroxidase ( P  < 0·01) increased, and malondialdehyde levels decreased ( P  < 0·01) in 90 kg pigs. Hepatic catalase ( P  = 0·04), muscle superoxide dismutase ( P  < 0·01) and copper–zinc-superoxide dismutase were enhanced ( P  = 0·01), whereas malondialdehyde levels were reduced ( P  = 0·05) by Lact. fermentum .
Conclusions:  The free radical-scavenging capacity of Lact. fermentum was dose dependent and its supplementation improved the antioxidant status of pigs.
Significance and Impact of the Study:  Lactobacillus fermentum could be used to alleviate oxidative stress and increase pig performance and improve pork quality.     

复合微生态制剂对断奶仔猪生产性能、粪便菌群及血液指标的影响

目的 探讨复合微生态制剂对断奶仔猪生长性能、粪便乳酸菌和大肠埃希菌数、血液红胞数以及血红蛋白含量及其对免疫水平的影响.方法 选择25日龄的断奶仔猪共108头,平均分为两组:Ⅰ组和Ⅱ组,每组3个重复,每个重复18只,Ⅰ组饲喂全价料+2.0‰复合微生态制剂;Ⅱ组为对照组,饲喂全价料,实验期为42 d.结果 至实验结束时,复合微生态制剂组的料重比显著低于对照组(P ＜0.05);14、28和42 d时复合微生态制剂组粪便中的大肠埃希菌数比对照组低7.94％,2.90％和4.89％,与对照组相比差异有统计学意义(P＜0.05);14d时,复合微生态制剂组粪便乳酸菌数与对照组相比差异有统计学意义(P＜0.05),28和42 d时,两组粪便乳酸菌数差异无统计学意义(P＞0.05).14、28和42 d时复合微生态制剂组血液中红细胞数和血红蛋白浓度均显著高于对照组.两组血清尿素氮水平差异无统计学意义(P＞0.05),复合微生态制剂组血清总蛋白和IgG的含量与对照组相比有升高的趋势,但差异无统计学意义(P＞0.05),复合微生态制剂组血清IgA和IgM的浓度显著高于对照组(P＜0.05).结论 复合微生态制剂可以显著降低断奶仔猪的料重比,降低粪便中大肠埃希菌数量,促进血液红细胞和血红蛋白的含量,提高断奶仔猪的免疫水平.     

Effects of Lactobacillus casei and Enterococcus faecalis on growth performance,immune function and gut microbiota of suckling piglets

This study was carried out to investigate the effects of orally administrated Lactobacillus casei and Enterococcus faecalis on performance, immune function and gut microbiota of suckling piglets. Neonatal piglets (n = 120) were randomly assigned to 4 groups, with 30 suckling piglets in each group. The piglets were from 15 litters, one male and one female piglet were selected for each group in each litter. The Control group was administrated with normal saline, the other groups with L. casei or E. faecalis or a combination of L. casei and E. faecalis at a ratio of 3:1. Each piglet was orally administrated with 1, 2, 3 and 4 ml probiotics or normal saline at the age of 1, 7, 14 and 21 d, respectively. The piglets were weaned at the age of 21 d. The results showed that compared with the Control group, the average daily gain of piglets administrated with probiotics was significantly increased, and the diarrhoea rate and mortality were significantly decreased (p < 0.05). After supplementation of the combined probiotics, the protease activity in stomach, duodenum and colon was increased and in all supplemented groups, the immunoglobulin A concentration in plasma was significantly higher (p < 0.05). The combined probiotics significantly increased villus length and the expression level of transforming growth factor-β in the jejunum (p < 0.05) but decreased the expression level of the jejunal tumour necrosis factor-α (p < 0.05). In addition, probiotics could regulate gut microbiota and increase microbial similarity coefficients for keeping piglet gut microbiota stable.     

Technological properties of Lactobacillus fermentum involved in the processing of dolo and pito, West African sorghum beers, for the selection of starter cultures

Aim: Technological properties of Lactobacillus fermentum isolates involved in spontaneous fermentation of dolo and pito wort were examined to select starter cultures. Methods and Results: 264 isolates were screened for antimicrobial activity, acidifying activity, exopolysaccharides (EPSs) and amylase production. An antimicrobial activity was detected for 33·3%, 31·8%, 22·7% and 15·9% of the isolates towards Staphylococcus aureus enterotoxin A producer, Staphylococcus aureus enterotoxin A and B producer, Escherichia coli and Listeria innocua, respectively. A similarity was found between the isolates which were clustered in four groups according to their rates of acidification of sorghum malt broth. The faster acidifying group of isolates (43·48%) had a rate of acidification evaluated as ΔpH of 1·14 ± 0·15 pH unit after 6 h of fermentation, followed by a second group of isolates (38·08%) with a similar rate of acidification after 9 h of fermentation. From the isolates endowed with an antimicrobial activity, 5·76% belonged to the faster acidifying group and 40·38% belonged to the second group. 88·7% of the isolates had the ability for producing EPSs but not amylase. Conclusion: Lactobacillus fermentum ferments dolo and pito wort by lowering the pH and providing organic acids, EPSs and antimicrobial compounds. Significance and Impact of the Study: Strains with a rapid rate of acidification, an antimicrobial activity and producing EPSs are suggested to have potential for starter cultures.     

Orally administered heat-killed Lactobacillus gasseri TMC0356 alters respiratory immune responses and intestinal microbiota of diet-induced obese mice

Aims: To investigate the influence of heat‐killed Lactobacillus gasseri TMC0356 on changes in respiratory immune function and intestinal microbiota in a diet‐induced obese mouse model. Methods and Results: Male C57BL/6J mice were fed a high‐fat diet for 16 weeks. After 8 weeks, the high‐fat‐diet‐induced obese mice (DIO mice) were randomly divided into two 0067roups, the DIO and DIO0356 groups. DIO0356 group mice were orally fed with heat‐killed TMC0356 every day for 8 weeks, while DIO group mice were exposed to 0·85% NaCl over the same time period as controls. After intervention, the pulmonary mRNA expression of cytokines and other immune molecules in DIO0356 mice compared to those in DIO group mice was significantly increased (P < 0·05, P < 0·01). In faecal bacterial profiles, analysed using the terminal restriction fragment length polymorphism (T‐RFLP) method, T‐RFLP patterns in 75% of the DIO0356 group mice were apparently changed compared with those in control group mice. Conclusion: These results suggest that inactive lactobacilli may stimulate the respiratory immune responses of obese host animals to enhance their natural defences against respiratory infection, partially associating with their potent impact on intestinal microbiota. Significance and Impact of the Study: We have demonstrated that oral administration of inactive lactobacilli may protect host animals from the lung immune dysfunction caused by obesity.     

副干酪乳杆菌N1115对肝硬化患者肠黏膜屏障功能的研究

目的 研究不同剂量副干酪乳杆菌对肝硬化患者肠黏膜屏障的影响。方法 选择我院肝硬化失代偿期患者42例,随机分为对照组和副干酪乳杆菌4 g、8 g、16 g组。各组均给予常规对症治疗。在此基础上,除对照组外,其余各组按相应剂量每日口服补充副干酪乳杆菌,连续2周。所有患者均于治疗前后测血清二胺氧化酶、脂多糖。结果 给予不同剂量副干酪乳杆菌治疗后,各组患者的二胺氧化酶和脂多糖均有所下降,但只有给予16 g副干酪乳杆菌治疗的患者二胺氧化酶和脂多糖与对照组相比差异有统计学意义（t=9.517、10.836,P＜0.05）,同时该组患者疗前后相比差异亦有统计学意义（t=9.445、7.701,P＜0.05）。结论 补充16 g/d副干酪乳杆菌能帮助改善肝硬化患者肠黏膜屏障功能。     

短链脂肪酸对肠道动力影响的研究进展

人体的肠道不仅仅是消化吸收场所,也是大量微生物生存的家园.肠道作为人体最大的储菌库,其多种生理功能离不开复杂多变的肠道菌群和菌群代谢物(如短链脂肪酸等)的参与.短链脂肪酸是肠道菌群发酵膳食纤维产生的一类重要的信号分子,研究发现短链脂肪酸除参与维持人体肠道黏膜免疫屏障、调节体液及电解质平衡以及为肠上皮细胞提供能量外,...     

Effects of three strains of intestinal autochthonous bacteria and their extracellular products on the immune response and disease resistance of common carp,Cyprinus carpio

The study isolated three strains of intestinal autochthonous bacteria Aeromonas veronii BA-1, Vibrio lentus BA-2, and Flavobacterium sasangense BA-3 from the intestinal tract of the common carp (Cyprinus carpio). To reveal the effects of these three strains of bacteria on the innate immunity of carp, the lysozyme, complement C3, total serum protein, albumin and globulin levels, respiratory burst activity, phagocytic activity by blood leucocytes and the expression of IL-1b, lysozyme-C, and TNF-α were examined after feeding with seven different diets for up to 28 days. Also the survival of carp against Aeromonas hydrophila was challenged for 14 days. The carp were fed seven different diets: one control, three diets supplemented with 1 × 10⁸ cell g⁻¹ of carp intestinal bacteria BA-1 (Group D-I), BA-2 (Group D-II) and BA-3 (Group D-III), and three diets supplemented with extracellular products FA-1 (Group E-I), FA-2 (Group E-II) and FA-3 (Group E-III) which were corresponding to the strains BA-1, BA-2, and BA-3, respectively, up to 28 days. For groups D-I, D-III, E-I and E-III, the innate immune parameters of carp were significantly increased, the expression of three immune-related genes in blood was significantly up-regulated examined during 7, 14, and 21 days of feeding, and the survival rate was improved. The study indicates that the two isolated intestinal autochthonous bacteria A. veronii BA-1 and F. sasangense BA-3 could positively influence immune response and enhance disease resistance of carp against A. hydrophila infection.