小麦蛋白水解物对嗜酸乳杆菌(Lactobacillus acidophilus)生长的影响研究

该研究对比了小麦蛋白水解物与不同蛋白胨对嗜酸乳杆菌生长的影响,重点从分子质量分布、氨基酸组成等方面解析了小麦蛋白水解物对嗜酸乳杆菌(Lactobacillus acidophilus)形态、活菌数、冻干存活率的影响。结果表明,小麦蛋白水解物是一种适用于嗜酸乳杆菌培养的有机氮源,同等培养条件下活菌数和冻干存活率高于其他蛋白胨,小麦蛋白水解物中分子质量为2000~5000 Da的组分是促进嗜酸乳杆菌生长的关键营养,含谷氨酰胺、脯氨酸组成的多肽可能是促进嗜酸乳杆菌缩短菌体,活菌数和冻干存活率提高的关键因素。该研究结果可为小麦蛋白水解物在嗜酸乳杆菌生产及其他发酵领域的应用提供一定的基础数据支撑。

嗜酸乳杆菌(Lactobacillus acidophilus)合成纳米硒特性研究

乳酸菌具有还原亚硒酸钠为纳米硒的能力。为了采用更加环境友好的方式获得纳米硒颗粒,本研究首先探索了培养基中加硒浓度、加硒时间,以及培养时长对嗜酸乳杆菌(Lactobacillus acidophilus)合成纳米硒的影响,随后对所产的纳米硒颗粒的粒径、zeta电位及抑菌活性进行研究。结果表明,当培养基中硒含量为0~600μg/mL时,硒浓度越高,转化得到的纳米硒越多;当培养基中硒浓度高于600μg/mL时,发酵液中的纳米硒含量反而减少。在嗜酸乳杆菌生长的对数中前期,即第6 h时添加亚硒酸钠,更有利于纳米硒的合成。而培养至32 h后,纳米硒几乎不再继续合成。通过扫描电镜及粒径和电位仪分析发现,嗜酸乳杆菌所产的纳米硒颗粒呈球形,且超声破碎有助于其释放;纳米硒颗粒带负电荷,电位绝对值为40~50 mV,粒径大小较多分布于170~210 nm,具有良好的稳定性。抑菌实验结果表明,嗜酸乳杆菌还原亚硒酸钠所产的纳米硒对大肠杆菌、沙门氏菌、金黄色葡萄球菌和枯草芽孢杆菌的生长均具有抑制作用。综上,嗜酸乳杆菌可以将亚硒酸钠还原合成纳米硒,且所产的纳米硒颗粒具有良好的抑菌活性。

牦牛肠源Lactobacillus acidophilus L3对其肠道分泌型免疫球蛋白A及免疫相关因子的影响

为了研究牦牛肠源Lactobacillus acidophilus L3（嗜酸乳杆菌）对其肠道分泌型免疫球蛋白A（SIg A）及免疫相关因子的影响,将10头健康牦牛（2～2.5岁）随机分为2组,分别为益生菌组和空白对照组,益生菌组在饲料中添加2×109CFU·kg-1L.acidophilus L3,饲喂28 d后取其小肠样品,ELISA检测试验组和对照组十二指肠、空肠、回肠中SIg A、白细胞介素-2（IL-2）、IL-4、IL-6、干扰素γ（IFN-γ）的含量。研究结果表明,L.acidophilus L3可有效增加试验组牦牛肠道SIg A的分泌量（P〈0.05）,组内比较发现SIg A在回肠含量最高,其次为空肠和十二指肠。IL-2、IL-4、IL-6在试验组小肠中的表达量较对照组显著增加（P〈0.05）,试验组小肠IFN-γ的表达量较对照组降低（P〈0.05）。证实L.acidophilus L3可提高牦牛肠道的黏膜免疫功能。

牦牛肠源Lactobacillus acidophilus L3对其小肠黏膜形态结构的影响

为了探讨牦牛肠源嗜酸乳杆菌Lactobacillus acidophilus L3对牦牛小肠肠道黏膜形态结构的影响,将10头健康牦牛（2~2.5岁）随机分为2组,分别为益生菌组和空白对照组,益生菌组在饲料中添加2×109CFU·kg-1L.acidophilus L3,饲喂28 d后取其小肠组织样品,采用组织学和显微测量学方法对益生菌组和空白对照组牦牛小肠绒毛高度、隐窝深度、绒毛高度/隐窝深度比值（V/C）,以及回肠黏膜淋巴集结厚度进行测量和统计分析。研究结果显示,益生菌组牦牛十二指肠、空肠、回肠绒毛高度均较空白对照组显著增加,隐窝深度降低,V/C值增加,差异有统计学意义（P〈0.05）。通过对回肠淋巴集结的测量发现,益生菌组牦牛回肠淋巴集结的平均厚度均较空白对照组显著增加,差异有统计学意义（P〈0.05）。研究结果表明,牦牛肠源L.acidophilus L3可有效改善其肠道黏膜结构,增强肠道黏膜免疫效应部位的免疫功能。

Effects of Lactobacillus acidophilus on the growth performance and intestinal health of broilers challenged with Clostridium perfringens

Background: Clostridium perfringens is the main etiological agent of necrotic enteritis. Lactobacil i show beneficial effects on intestinal health in infectious disease, but the protective functions of lactobacil i in C. perfringens-infected chickens are scarcely described. This study examined the effects of Lactobacil us acidophilus(L. acidophilus) on the growth performance and intestinal health of broiler chickens chal enged with Clostridium perfringens(C. perfringens) over a 28-day period. Using a 2 × 2 factorial arrangement of treatments, a total of 308 1-day-old male Arbor Acres broiler chicks were included to investigate the effects of Lactobacil us acidophilus(L. acidophilus) on the growth performance and intestinal health of broiler chickens chal enged with Clostridium perfringens(C. perfringens) during a 28-day trial.Results: During infection(d 14–21), C. perfringens challenge decreased the average daily gain(P < 0.05), and increased feed conversion ratio and the mortality rate(P < 0.05). However, dietary supplementation with L. acidophilus increased the body weight of C. perfringens-infected broilers on d 21(P < 0.05), and tended to decrease the mortality(P = 0.061).C. perfringens challenge decreased the villus height(P < 0.05), the ratio of villus height to crypt depth(P < 0.05) and OCLN(occludin) m RNA expression(P < 0.05), and increased the pro-inflammatory cytokine expression in the spleen and jejunum, the intestinal populations of C. perfringens and Escherichia(P < 0.05), and the serum content of endotoxin(P < 0.05), regardless of L. acidophilus supplementation. In contrast, dietary L. acidophilus reducedthe intestinal lesion score of challenged broilers(P < 0.05), the m RNA expression of pro-inflammatory cytokines, ileal populations of Escherichia and serum endotoxin content(P < 0.05), but increased the intestinal Lactobacillus populations(P < 0.05),irrespective of C. perfringens challenge.Conclusion: Dietary addition of L. acidophilus could improve the intestinal health and reduce the mortality of broilers suffering from necrotic enteritis.

Effects of exogenous enzymes, Lactobacillus acidophilus or their combination on feed performance response and carcass characteristics of rabbits fed sugarcane bagasse

The aim of this study was to evaluate the effect of Lactobacillus acidophilus（LAC）, exogenous enzymes of ZAD（exogenous enzyme preparation） or their combination on feed conversion, and dressing of rabbits fed different treatments of sugarcane bagasse（SCB）. Five rations were allotted randomly to five groups of New-Zealand White（NZW） rabbits（n=10） with initial live body weight of（838±42.4） g and 5 weeks of age. Rabbits were fed on diets with different sources of fiber as follows,（i） a control diet composed of 100% berseem hay and 0% SCB,（ii） 50% berseem hay and 50% untreated SCB（USCB）,（iii） 50% berseem hay and 50% SCB treated with L. acidophilus（LAC）,（iv） 50% berseem hay and 50% SCB treated with ZAD（ZAD）, and（v） 50% berseem hay and 50% SCB treated with a combination of LAC＋ZAD（LZ）. Treatments of SCB with L. acidophilus, ZAD and LAC＋ZAD had the highest feed conversion ratio than both USCB and control. The dressing percentage of rabbits that fed the LAC and LZ diets was higher（P〈0.05） compared with that in the other groups. Performance index（PI） for LAC group was improved（P〈0.05） compared to that for the other groups; however, PI for USCB group was the lowest（P〈0.05）. It could be concluded that treating SCB with L. acidophilus, exogenous enzymes of ZAD or their combination improved feed conversion and performance with more positive effects with L. acidophilus than the other treatments.

Efficacy profiles for different concentrations of Lactobacillus acidophilus in experimental colitis

AIM:To determine the efficacy profiles of different concentrations of Lactobacillus acidophilus(L.acidophilus)for treating colitis using an experimental murine model.METHODS:Colitis was established in 64 BALB/c mice by adding 5%dextran sodium sulfate(DSS)to the drinking water and allowing ad libitum access for 7 d.The mice were then randomly divided into the following control and experimental model groups(n=8 each;day 0):untreated model control;negative-treatment model control(administered gavage of 1 mL/10 g normal saline);experimental-treatment models C4-C8(administered gavage of 104,105,106,107,or 108CFU/10 g L.acidophilus,respectively);positive-treatment model control(administration of the anti-inflammatory agent prednisone acetate at 45 g/10 g).Eight mice given regular water(no DSS)and no subsequent treatments served as the normal control group.Body weight,fecal traits,and presence of fecal occult blood were assessed daily.All animals were sacrificed on post-treatment day7 to measure colonic length,perform histological scoring,and quantify the major bacteria in the proximal and distal colon.Intergroup differences were determined by one-way ANOVA and post-hoc Student-Newman-Keuls comparison.RESULTS:All treatments(L.acidophilus and prednisone acetate)protected against colitis-induced weight loss(P<0.05 vs model and normal control groups).The extent of colitis-induced colonic shortening was significantly reduced by all treatments(prednisone acetate>C4>C5>C7>C8>C6;P<0.05 vs untreated model group),and the C6 group showed colonic length similar to that of the normal control group(P>0.05).The C6 group also had the lowest disease activity index scores among the model groups.The bacterial profiles in the proximal colon were similar between all of the experimental-treatment model groups(all P>0.05).In contrast,the bacterial profile in the distal colon of the C6 group showed the distinctive features(P<0.05 vs all other experimental-treatment model groups)of Lactobacillus sp.and Bifidobacterium sp.being the most abundant bacteria and Staphylococcus aureus being the least abundant bacteria.CONCLUSION:The most therapeutically efficacious concentration of L.acidophilus(106CFU/10 g)may exert its effects by modulating the bacterial profile in the distal colon.

Detection of Lactobacillus acidophilus in Fermented Material by Real-time Fluorescent Quantitative PCR

The species distinctive PCR primer of Lactobacillus acidophilus （ L. acidophilus） was designed according to 16S rRNA gene sequences of conunon Lac- tobacillus species in fermented material. Bacterial genome DNA of separated L. acidophilus in fermented sample was taken as template, and L. acidophilus in fer- mented material was conducted the quantitative determination by real-time quantitative PCR （RT-PCR）. Analysis on RT-PCR results shown that contents of L. aci- dophilus in the test sample reached 1.5 billion CFU / g. Test results shown that contents of L. acidophilus in fermented material could be detected accurately by the established RT-PCR method in the test. indicating that the established RT-PCR method could be aookued to the detection of L. acidophilus in fermented material.

Effect of Lactobacillus acidophilus as a Dietary Supplement on Nonspecific Immune Response and Disease Resistance in Juvenile Common carp, Cyprinos carpio

Effects of diet fortified with Lactobacillus acidophilus at 0.0%, 0.2%, 0.4% and 0.6% on nonspecific immune response and disease resistant common carp juvenile infected with Pseudomonas aeruginosa and Aeromonas hydrophilla were examined. Immune response parameters （the total protein, albumin, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, urea, creatinine and immunoglobulin）, percentage mortality and relative protection level were determined on day 1 and days 14, 28, 42 and 56. Fish fed Lactobacilus acidophilus fortified diet significantly improved nonspecific immune parameters especially group treated with 0.4% inclusion with lower mortality rate indicating a better relative protection level against Pseudomonas aeruginosa and Aeromonas hydrophilla.

应用嗜酸乳杆菌(Lactobacillus acidophilus)发酵薄荷抗氧化功能研究

采用嗜酸乳杆菌发酵薄荷以保持或增强其抗氧化性。研究结果表明,经发酵后,与相应未发酵对照相比,根茎叶发酵液总抗氧化性提高至54.2%~74.9%间,清除DPPH自由基能力分别提高至67.7%~70.9%间,清除超氧阴离子自由基的能力则分别提高至29.9%~30.4%间,且与发酵前差异具有显著性(P<0.05)。进一步对发酵前后总酚、总黄酮等抗氧化物质含量分析发现,根茎叶总酚总黄酮含量在发酵后均上升,分别提升至12.0%~12.7%及15.6%~20.1%间,且茎叶与发酵前相比差异呈现显著性(P<0.05)。最终发酵产品感官品评方面,只叶部颜色与根茎差异呈现显著性,其它指标差异均不具显著性(P>0.05)。该研究对于薄荷的发酵功能性产品开发提供了新思路。

益生菌Lactobacillus casei Zhang对凝固型发酵乳质构和挥发性风味物质的影响

【目的】评价益生菌Lactobacillus casei Zhang(L.casei Zhang)货架期内活菌数的变化及其对发酵乳物理特性和挥发性风味物质的影响。【方法】将2株Streptococcus thermophilus(S.thermophilus)分别与益生菌L.casei Zhang复配发酵,发酵结束(pH 4.5)于4℃冷藏28 d,并对发酵乳各指标进行测定。【结果】4℃贮藏28 d时,发酵乳中益生菌L.casei Zhang活菌数没有显著性变化(P<0.05),且数量保持在108CFU/g以上;益生菌L.casei Zhang与S.thermophilus复配发酵有利于提高3-羟基-2-丁酮和己酸等挥发性风味物质的含量,同时短期贮藏过程中(1—7 d)可赋予产品较高的黏度、硬度、脆度、胶性和耐嚼性,随着贮藏时间的延长其对产品物理特性的影响随发酵用S.thermophilus菌株的不同而呈现不同的变化。【结论】4℃贮藏28 d过程中,益生菌L.casei Zhang具有非常好的稳定性,同时其与S.thermophilus复配发酵可赋予产品较好的质构和风味。

益生菌Lactobacillus casei Zhang对凝固型发酵乳感官品质的影响

【目的】评价益生菌Lactobacillus casei Zhang(L.casei Zhang)对凝固型发酵乳感官品质的影响。【方法】将Streptococcus thermophilus(S.thermophilus)与益生菌L.casei Zhang复配发酵,发酵结束(pH4.5)于4℃冷藏1 d或28 d,并对发酵乳进行感官鉴评试验。【结果】益生菌L.casei Zhang与S.thermophilus复配发酵可赋予产品更好的细腻性、更为浓郁的奶油味和乙醛风味,从而提升产品的风味总体得分、气味总体得分及产品总得分。4℃贮藏7 d时益生菌发酵乳具有最好的气味和风味感官特征,而贮藏14 d时具有最好的表观和质地感官特征。【结论】益生菌L.casei Zhang可提高发酵乳制品的感官品质,同时贮藏时间对发酵乳感官特性产生影响。

饲喂益生菌Lactobacillus casei Zhang对高脂日粮大鼠肝脏脂质代谢的作用

【目的】研究不同剂量益生菌L.casei Zhang(2.0×1010CFU/d、2.0×109CFU/d和2.0×108CFU/d)及其发酵乳饮料(2.0×108CFU/mL/d)对高胆固醇血症大鼠肝脏脂质的治疗作用。【方法】采用高脂饲料诱导高脂血症,采用相应试剂盒测定肝脏总胆固醇水平(TC)和甘油三酯(TG)水平、粪便总胆汁酸水平与胆固醇水平以及血清载脂蛋白ApoAⅠ与ApoB水平。【结果】益生菌各剂量组和发酵饮料组与高脂模型组相比,肝脏总胆固醇水平(TC)和甘油三酯(TG)水平均显著降低(P<0.05或P<0.01)。各试验组均可显著增加高血脂大鼠粪便总胆汁酸水平和血清载脂蛋白ApoAⅠ水平以及显著降低血清载脂蛋白ApoB水平(P<0.01),但对粪便胆固醇水平影响不明显(P>0.05)。【结论】益生菌L.casei Zhang主要通过增加总胆汁酸的排出和调节载脂蛋白水平来改善高血脂大鼠肝脏脂质水平。

利用Lactobacillus casei Zhang开发益生菌新鲜干酪

通过添加不同比例Lactobacillus casei Zhang发酵剂制作新鲜干酪，并对其在新鲜干酪中的活力和添加Lactobacillus后新鲜干酪的理化性质进行了研究。结果表明，Lb．casei Zhang在新鲜干酪中具有较高的活力，添加2％、1％、0．5％Lb．casei Zhang发酵剂的干酪中，4℃冷藏开始前，Lb．casei Zhang活菌数分别为2．24×10^8 cfu／g，1．38×10^8 cfu／g，5．55×10^8 cfu／g，4℃冷藏28d后，Lb．casei Zhang存活率分别为99．12％，98．31％，98．61％。在制作过程中和4℃冷藏过程中，与空白组相比，添加Lb．casei Zhang对新鲜干酪的pH值、滴定酸度、蛋白水解活性影响都不显著（P〉0．05）。

益生菌Lactobacillus casei Zhang增殖培养基的优化

Lactobacillus casei Zhang是一株分离自传统酸马奶中的益生菌。本文研究了不同碳源、氮源、碳氮比例、微量元素及缓冲盐对Lactobacillus casei Zhang增殖培养的效果,并采用响应面法对优选的碳源、氮源和缓冲盐类的组成含量进行优化,得到Lactobacillus casei Zhang的增殖培养基为:葡萄糖20.9g/L、大豆蛋白胨10.45g/L、酵母粉10.45g/L、K2HPO43.5g/L、醋酸钠14.6g/L、柠檬酸钠2.3g/L、MgSO4·7H2O1g/L、MnSO4·5H2O54mg/L、CuSO4·5H2O10mg/L、吐温80为1g/L。LactobacilluscaseiZhang在此增殖培养基中经37℃18h培养活菌数可达到4.78×109CFU/mL,比在MRS中(4.8×108CFU/mL)提高近10倍。

喂饲Lactobacillus casei Zhang对大鼠体内脂质代谢的影响

从内蒙古锡林郭勒盟正蓝旗传统酸马奶中分离筛选到1株降胆固醇功效较好的乳杆菌Lactobacillus．casei Zhang。用Lb．casei Zhang灌胃高脂血症模型大鼠研究其对血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)的影响。结果表明:灌胃14 d后,Lb．casei Zhang热致死菌体组大鼠血清中TC浓度较对照组显著降低(P<0．01),TG浓度虽有降低但不呈显著性,同时HDL-C浓度显著升高(P<0．05);Lb．casei Zhang活菌体组大鼠血清中TC、TG浓度均有所降低,HDL-C浓度升高,但未呈显著性。灌胃28 d后,Lb．casei Zhang热致死菌体组大鼠血清中TC浓度较对照组显著降低(P<0．05),Lb．casei Zhang活菌体组TC浓度及两组TG、LDL-C浓度降低,但差异不显著,HDL-C未发生明显的改变。Lb．casei Zhang热致死菌体组和活菌体组粪便中的胆酸含量均增高,但只有热致死菌体组差异显著(P<0．05)。通过实验表明Lb．casei Zhang通过菌体对胆固醇的吸收吸附及减少肝肠循环中的胆酸来达到降血脂的功效。

Effect of Flaxseed on Bile Tolerances of <i>Lactobacillus acidophilus, Lactobacillus bulgaricus</i>, and <i>Streptococcus thermophilus</i>

Consumption of flaxseed provides health benefits. Bile tolerance allows survival of probiotics in the intestinal tract. The objective was to determine whether or not flaxseed enhances bile tolerance of Lactobacillus acidophilus (L. acidophilus) LA-K, Lactobacillus delbruekii ssp. bulgaricus (L. bulgaricus) LB-12, and Streptococcus salivarius ssp. thermophilus (S. thermophilus) ST-M5. Control and experimental (62 g flaxseed/L) broths containing 0.3% oxgall were prepared for each culture, sterilized, cooled, inoculated, and plated for 8 h. Growth of each microorganism in both the control and experimental broths was evaluated by the slope of the regression line of its log count versus time after inoculation. Flaxseed significantly enhanced growth of L. acidophilus but not L. bulgaricus and S. thermophilus over 8 h compared to its corresponding control. Therefore, flaxseed improved the bile tolerance of L. acidophilus but not of S. thermophilus and L. bulgaricus.

益生菌Lactobacillus casei Zhang冻干粉对小鼠急性毒性的研究

通过研究益生菌Lactobacillus casei Zhang冻干粉对小鼠急性毒性作用,为该菌株的安全应用提供依据。连续14d对小鼠灌胃不同剂量的L.casei Zhang冻干粉,各剂量组小鼠的一般体征、肝脏功能、脏器指数以及肝、肾、脾形态学的观察结果与对照组相比无显著差异(P>0.05)。急性毒性试验及相关指标检测结果显示L.casei Zhang冻干粉无毒副作用。

益生菌Lactobacillus casei Zhang在酸胁迫下的蛋白质组学研究

Lactobacillus casei Zhang是1株筛选自发酵酸马奶,并具有耐酸等益生特性的益生乳杆菌。该研究利用蛋白质组双向电泳,比较了其在pH值为7.0和5.5的培养液中分别生长至对数生长期中期的蛋白质组表达差异。结果表明,有11个蛋白质点表达发生明显变化,经过基质辅助激光解吸/电离飞行时间质谱鉴定,其中有3个表达增强的蛋白质点分别鉴定为翻译因子(EF-Tu),N-乙酰氨基葡萄糖-6-磷酸脱醛酶(NagA)和小热休克蛋白(sHsp)。酸胁迫可诱导乳酸菌产生复杂的酸应激反应,涉及不同的代谢调控途径。

Lactobacillus casei AST18抗真菌特性生及其在酸奶保鲜中的应用

[目的]考察来源于中国传统发酵制品中乳酸菌的抑真菌特性,研究其在酸奶贮藏中的抑制霉菌效果。[方法]高效液相色谱法(HPLC)检测7株具有抗真菌效果的乳杆菌发酵液中苯乳酸(PLA)含量,研究PLA与乳杆菌发酵液抗真菌活性的相关性。选取抑菌活性最强的菌株Lactobacillus casei AST18进行抑菌特性研究。Lactobacillus casei AST18分别以2%、4%、6%、8%接种量作为辅助发酵剂添加至酸奶发酵工艺中,成品酸奶贮藏期间,监测酸奶中霉菌生长状况,检测酸奶理化指标并进行感官评定。[结果]乳杆菌发酵液中苯乳酸含量与其抑真菌直径间相关关系不显著。Lactobacillus casei AST18发酵上清液经胃蛋白酶和胰蛋白酶处理后不影响其抑菌活性,而环境pH对其抑菌活性的影响显著,热处理可使其丧失抑菌活性。Lactobacillus caseiAST18以2%添加量作为辅助发酵剂应用在酸奶中可抑制霉菌菌丝生长和孢子生成,且对酸奶产品风味、感官品质无显著影响。[结论]Lactobacillus casei AST18具有较好的抑制霉菌生长能力,应用在酸奶中具有显著的防霉保鲜效果。