一株枯草芽孢杆菌的分离鉴定及其益生潜质分析

从养猪场健康成年猪粪便中分离、筛选出1株芽孢杆菌。经培养特征、形态观察、生理生化试验以及16S rDNA序列分析相似度为98.99%,确定该菌株为枯草芽孢杆菌,并进行了该枯草芽孢杆菌与肠道细菌在体外的生长竞争实验。结果表明:肠道厌氧菌群中的双歧杆菌、乳酸杆菌和拟杆菌数量均有不同程度增多,而肠杆菌、肠球菌等需氧菌群数量则有所减少。证明该菌株能促进肠道厌氧菌群的生长,而抑制需氧菌群的生长。可见,枯草芽孢杆菌能起到维持肠道微生态平衡的作用,是一株比较理想的潜在益生菌。     

不同剂量植物乳杆菌对小鼠肠道菌群的影响

植物乳杆菌是人体肠道中的益生菌,可自发酵乳肉制品中分离。本实验将处于正常生理状态下的小鼠分为4组,通过灌喂不同剂量的植物乳杆菌X3-2B来探讨其对小鼠肠道各类微生物菌群的影响。结果表明,灌喂植物乳杆菌X3-2B时,小鼠对饲料的利用率优于对照组,且小鼠粪便p H低于对照组(高剂量组最低)。灌喂乳酸菌的小鼠其肠道内乳酸菌与双歧杆菌数显著(p<0.05)高于对照组。高剂量组与中剂量组小鼠在灌喂14d时小鼠肠道内大肠杆菌数无显著差异,但总肠杆菌和肠球菌数显著低于灌喂第1d(p<0.05),即植物乳杆菌X3-2B对肠道内致病菌有一定的抑制作用,对肠道微生物区系有一定的调节作用。     

川佛手精油抗氧化及抑菌活性的研究

为了研究川佛手精油的抗氧化和抑菌活性,以石油醚作为溶剂超声辅助提取得到川佛手精油,测定其抗氧化活性和体外抑菌活性,川佛手精油对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌、苏云金芽孢杆菌、肠球菌5种常见食源性污染菌的抑菌效果。结果表明:川佛手精油含有丰富的多酚和黄酮类物质,具有一定的抗氧化活性,对DPPH和ABTS自由基清除能力较强,EC50分别为3.92,1.88mg/mL。体外抑菌试验表明川佛手精油对肠球菌有很好的抑菌效果,最低抑菌浓度(MIC)为24mg/mL,抑菌强弱顺序为:肠球菌、苏云金芽孢杆菌、枯草芽孢杆菌、金黄色葡萄球菌、大肠杆菌。     

自然发酵甜面酱中一株芽孢杆菌的分离鉴定及益生特性初探

从自然发酵甜面酱中分离筛选出一株淡红色的芽孢杆菌B30,经形态学、生理生化特征鉴定,16SrDNA序列分子鉴定和系统发育树分析,确定该菌为枯草芽孢杆菌(Bacillus subtilis)。对该菌进行产酶活性、人工肠胃液、猪胆盐耐受性试验,结果表明:该菌具有产蛋白酶和淀粉酶活性,对人工肠液、胃液和猪胆盐环境均有很强的耐受性。因此,此次研究得到的枯草芽孢杆菌具有良好的益生菌开发前景,是一株比较理想的潜在益生菌。     

枯草芽孢杆菌对黑仔期菲律宾鳗鲡生长、体成分和消化酶活性的影响

目的:探讨枯草芽孢杆菌对黑仔期菲律宾鳗鲡生长性能、体成分和消化酶的影响,研究枯草芽孢杆菌在其饲料中的最适添加量。方法:在饲料中添加不同量枯草芽孢杆菌(2.0×1010cfu/g),配制5组分别含0%,0.3%,1%,3%,5%枯草芽孢杆菌的等氮配合饲料,饲喂初始体重为(16.01±1.15)g的5组黑仔期菲律宾花鳗鲡80 d。每组3个重复,每个重复60尾,共900尾。结果表明:枯草芽孢杆菌对黑仔期菲律宾鳗鲡摄食量、饲料转化率有显著影响(P0.05)。与对照组相比较,枯草芽孢杆菌添加组黑仔期菲律宾鳗鲡增重率和特定生长率呈先升后降趋势,有显著性差异(P0.05)。枯草芽孢杆菌对黑仔期菲律宾花鳗鲡肠体指数、肝体指数、肥满度3个形体指标有显著影响(P0.05),对空壳率的影响差异不显著(P0.05)。枯草芽孢杆菌添加对黑仔期菲律宾鳗鲡4个体成分指标无显著影响(P0.05),而在水分、粗蛋白质、粗脂肪、氨基酸总量呈现出不同的波动规律。枯草芽孢杆菌对黑仔期菲律宾鳗鲡肠道、肝脏蛋白酶、淀粉酶、脂肪酶活性有显著影响(P0.05),除肝脏脂肪酶外,均呈现先升后降的变化趋势(P0.05)。以增重率为评价指标,建立回归方程,预测枯草芽孢杆菌添加量为2.50%,活菌数达5×108cfu/g时,黑仔期菲律宾鳗鲡具有最大理论增重率(90.95%)。结论 :黑仔期菲律宾鳗鲡饲料中枯草芽孢杆菌最佳添加量2.50%(5×108cfu/g),能促进鱼体生长,提高饲料转化率,而对鱼体组成没有影响。     

益生菌膳食纤维粉在肠道功能障碍人群中的应用

本研究制备一种益生菌膳食纤维粉,选取20名社区肠道功能障碍自愿者参与试验,研究益生菌膳食纤维粉在肠道功能障碍人群中的应用情况。经过连续3个月的服用,自愿者的肠道功能发生明显改善,其中自愿者肠道动力发生显著提高(P0.05);血液内肠动力相关指标发生显著提高(P0.05);粪便中水分、p H值和脂肪酸含量明显提高(P0.05);肠道菌群中乳酸杆菌和双歧杆菌数量显著升高(P0.05),而肠杆菌、肠球菌和类杆菌数量显著减少(P0.05)。在试验过程中未发生任何不良反应事件,结果表明所制备的益生菌膳食纤维粉安全有效,具有应用价值。     

微热协同超高压处理杀灭芽孢杆菌芽孢效果的研究

采用比色法研究了微热协同超高压处理对枯草芽孢杆菌与嗜热脂肪芽孢杆菌芽孢的影响。结果表明,微热协同超高压处理芽孢能够显著提高芽孢2,6-吡啶二羧酸(DPA)的泄漏率(p<0.05)。处理组550、600MPa,50、60、70℃作用于枯草芽孢杆菌与嗜热脂肪芽孢杆菌芽孢,破坏芽孢结构,通透性屏障破坏,导致DPA的泄漏。所泄漏的DPA与灭菌对照组(121℃,30min)相比差异不显著(p>0.05),主要是芽孢质中的DPA。说明微热处理协同超高压杀灭枯草芽孢杆菌与嗜热脂肪芽孢杆菌芽孢的原因可能是其物理结构的破坏。     

酸茶发酵样品微生物与化学成分研究

运用分光光度、高效液相色谱、纯培养和Illumina MiSeq测序等技术研究德昂族酸茶发酵过程化学成分与微生物变化,为品质改善、产品开发提供一定的科学依据。测定发现:发酵A的水浸出物、表儿茶素、表儿茶素没食子酸酯、表没食子酸儿茶素没食子酸酯、咖啡碱、没食子酸含量显著下降(p0.05),表没食子酸儿茶素、水解单宁显著上升(p0.05);发酵B中,除游离氨基酸含量显著上升外(p0.05),其他成分无显著差异(p0.05)。分离鉴定出芽孢杆菌(Bacillus)、不动杆菌(Acinetobacte)、根毛霉(Rhizomucor)、Lachancea、酵母(Saccharomycetales)。二代测序发现优势细菌为厚壁菌门(Firmicutes)和变形杆菌门(Proteobacteria),优势真菌为子囊菌门(Ascomycetes);鉴定到乳杆菌(Lactobacillus)、乳球菌(Lactococcus)、肠球菌(Enterococcus)等益生菌。综上,酸茶富含益生菌,具有一定开发价值。     

枯草芽孢杆菌中性蛋白酶的研究进展

中性蛋白酶因作用条件温和广泛应用于食品、医药以及饲料等领域。枯草芽孢杆菌为肠道益生菌,且具有较强的蛋白酶活性 而受到极大关注。该文对枯草芽孢杆菌中性蛋白酶的特性与应用、提高枯草芽孢杆菌中性蛋白酶活力的途径以及枯草芽孢杆菌中性 蛋白酶的分离纯化方法进行了综述,并对存在的问题进行了分析与展望,旨在为枯草芽孢杆菌产中性蛋白酶的深入研究提供参考。     

枯草芽孢杆菌对冰鲜罗非鱼肠道菌群的调节及保鲜作用

采用一株枯草芽孢杆菌(BS08)作为饲料添加剂喂养罗非鱼,研究其对冰鲜罗非鱼肠道菌群的影响,尤其是对鱼体腐败菌的粘附、定植和滋生的影响,并研究枯草芽孢杆菌延缓冰鲜罗非鱼腐败的作用。通过饲料中添加枯草芽孢杆菌,水体中添加腐败菌(希瓦氏菌和假单胞菌)的方式分组喂养罗非鱼后,对罗非鱼进行冰鲜贮藏,通过高通量测序确定枯草芽孢杆菌和腐败菌对冰鲜过程中罗非鱼肠道菌群的影响,并以TVB-N和K值为腐败指标,研究冰鲜鱼腐败的程度。结果表明:枯草芽孢杆菌对罗非鱼的肠道菌群的变化具有阻遏作用,使菌群多样性维持在一个相对稳定的水平。希瓦氏菌在肠道内定植程度大于假单胞菌,枯草芽孢杆菌可定植在鱼肠道内,并抑制希瓦氏菌在鱼肠道内定植,最终显著遏制希瓦氏菌在肠道中的优势富集。以TVB-N和K值为指标判断鱼的鲜度,添加枯草芽孢杆菌可显著延缓冰鲜鱼的腐败程度。     

芽孢杆菌的产酶特性及其对抗生素的耐受性

以4株枯草芽孢杆菌（Bacillus subtilis）和2株地衣芽孢杆菌（Bacillus licheniformis）为研究对象,通过测定其成胞率、中性蛋白酶活性及对24种抗生素的耐受性,从中筛选优良芽孢杆菌。结果表明,从6株芽孢杆菌中筛选得到3株成胞率和产中性蛋白酶均较好的芽孢杆菌,分别为枯草芽孢杆菌BLCC1-0552、BLCC1-0615和地衣芽孢杆菌BLCC1-0441,液体发酵24 h后,成胞率较高,均达到98%;中性蛋白酶活性分别为90.58 U/mL、100.32 U/mL和24.72 U/mL。其中,枯草芽孢杆菌BLCC1-0615固体发酵玉米-豆粕型常规饲料产中性蛋白酶活力最高,发酵48 h时达到2 154.49 U/g。3株芽孢杆菌对抗生素的耐受性不一致,其中枯草芽孢杆菌BLCC1-0615对24种抗生素中的17种表现敏感,敏感率最高为70.83%。因此,确定优良菌株为枯草芽孢杆菌BLCC1-0615,其成胞率、产中性蛋白酶能力好及对抗生素耐受性较低,具有作为饲料添加剂应用于畜禽饲料中的潜力。     

The functional property of Bacillus for shrimp feeds

In shrimp cultures, feed represents the most expensive production cost. The quantity and quality of diets are primary factors influencing shrimp growth, nitrogen loading of the culture system and disease proliferation. For these reasons there is an interest in developing 'environmentally friendly' feeds for optimal growth. In this study, Bacillus strains were isolated from marine environments. The isolates were qualitatively assayed for proteases, carbohydrolases and lipases using selective media. The selected strains (9b, 31 and 33) were molecularly identified as Bacillus subtilis, B. megaterium and B. megaterium, respectively. Subsequently the strains were grown in an inexpensive culture medium (soybean mineral medium (MMS)). The information generated from the present investigation may contribute towards better feed formulations for shrimp at low cost, including bacterial strains as probiotics.     

4 种虾脂肪的提取及其脂肪酸组成的气相色谱分析

采用混合有机溶剂法从南极磷虾、对虾、河虾和罗氏虾中提取脂肪,分别考察提取溶剂、提取时间、料液比和提取温度对虾脂肪得率的影响,确定虾脂肪的最佳提取条件为：提取溶剂为石油醚-乙酸乙酯（2∶1,V/V）、提取时间60 min、料液比1∶5（g/mL）、提取温度50 ℃。在此条件下南极磷虾、对虾、河虾和罗氏虾的脂肪得率分别为4.39%、2.80%、2.98%和3.30%。采用气相色谱法分析4 种虾脂肪的脂肪酸组成,结果表明,4 种虾脂肪的不饱和脂肪酸含量较高,且都在60%以上,其中单不饱和脂肪酸的含量为17.08%～34.23%,多不饱和脂肪酸的含量为36.89%～48.28%。4 个虾品种间脂肪的脂肪酸组成和含量存在一定的差异,南极磷虾的二十碳五烯酸和二十二碳六烯酸总量最高,达31.27%,而河虾的油酸和花生四烯酸的含量最高。     

响应面法优化蛋壳豆渣发酵工艺生产高钙饲料

大量废弃的蛋壳和湿豆渣是良好的钙和氮素资源,为探索一条解决两类农业废弃物合理利用的新途径,本实验选用枯草芽孢杆菌、植物乳杆菌和粪肠球菌固体生料发酵鸡蛋壳、豆渣混合物。以乳酸钙含量为指标,利用单因素实验研究了豆渣蛋壳比例、固水比、葡萄糖添加量、接种量、混合菌种比例、发酵温度和发酵时间对发酵产乳酸钙的影响,并利用响应面试验优化发酵产乳酸钙的工艺条件。实验结果表明:在豆渣蛋壳比例90:10、枯草芽孢杆菌:植物乳杆菌:粪肠球菌为1:1:1(体积比)、固水比1:2.5、葡萄糖添加量15.6%、接菌量14.7%、发酵温度37℃、发酵6 d的条件下,蛋壳豆渣混合物中的乳酸钙含量达到13.58%。与发酵前相比,发酵后豆渣饲料中的游离氨基酸、乳酸钙含量显著提高(P<0.05),pH、粗脂肪、可溶性蛋白显著降低(P<0.05)。综上所述,利用益生菌发酵蛋壳与豆渣,可以制备一种高钙饲料。     

Effects of Bacillus subtilis natto on performance and immune function of preweaning calves

The effects of Bacillus subtilis natto on performance and immune function of dairy calves during the preweaning phase were investigated in this study. Twelve Holstein male calves 7 ± 1 d of age were randomly allotted to 2 treatments of 6 calves. The Bacillus subtilis natto was mixed with milk and fed directly to the calves. The calves were weaned when their starter intake reached 2% of their weight. Blood was collected and IgA, IgE, IgG, IgM, and cytokine levels in the serum of all the calves were determined. The results showed that Bacillus subtilis natto increased general performance by improving the average daily gain and feed efficiency and advanced the weaning age of the calves. No difference was observed in serum IgE, IgA, and IgM, whereas serum IgG was higher in the Bacillus subtilis natto-supplemented calves than in the control calves. Furthermore, calves fed with Bacillus subtilis natto were found to secrete more IFN-γ, but tended to produce less IL-4 than did the control calves, although serum IL-6 and IL-10 were not affected. This study demonstrated that Bacillus subtilis natto did not stimulate IgE-mediated allergic reactions, but increased serum IgG and IFN-γ levels in the probiotic-fed calves. We propose that the viable probiotic characteristics of Bacillus subtilis natto benefit calf immune function.     

Screening of 42 Bacillus isolates for ability to ferment soybeans into dawadawa

Forty-two cultures of Bacillus species isolated from soybean dawadawa were screened for their proteolytic activity on Skim Milk Agar, amylolytic activity on Starch Agar, and ability to grow on Soybean Agar. Distinct differences were observed between the cultures for all the criteria. Eleven isolates were selected for laboratory fermentation trials and each produced soybean dawadawa which was found acceptable by a taste panel. The pH of the samples, which increased from 6.37-6.58 to 8.22-8.85 during fermentation, were significantly different at P< or =0.05 for the different cultures. In the fermented samples, Bacillus counts exceeded 10(9) cfu/g, with the population of only one sample being significantly different at P< or =0.05. A market focus group familiar with soybean dawadawa selected Bacillus subtilis 24BP(2) and B. subtilis FpdP(2) as the best potential starter cultures. A taste panel found no significant differences in overall acceptance between soybean dawadawa either fermented spontaneously or with B. subtilis 24BP(2) and also between soybean dawadawa fermented with either B. subtilis 24BP(2) or B. subtilis FpdP(2).     

Distribution and residue depletion of oxytetracycline in giant freshwater prawn (Macrobrachium rosenbergii)

Distribution and residue depletion patterns of oxytetracycline were examined in giant freshwater prawns, Macrobrachium rosenbergii, after medicated-feed treatment at the feeding level of 4 g/kg of feed for 5 consecutive days. The concentration of oxytetracycline in prawn muscle tissues was measured using high-performance liquid chromatography equipped with a fluorescence detector. The limit of detection was 0.1 microg/g. In the medicated-feed-treated group, oxytetracycline was detectable 8 days posttreatment at the feeding level of 4 g/kg of feed for 5 consecutive days. The depletion half-life and mean residence time of oxytetracycline were 30.96 and 100.3 h, respectively. The dose of 4 g/kg of feed for 5 consecutive days can be recommended for therapeutic dosage regimen in giant freshwater prawn aquaculture. The minimal withdrawal period of M. rosenbergii muscle tissue should be 8 days postcessation of medicated feed.     

益生菌纳豆芽孢杆菌的筛选

益生菌克服了非营养性添加剂特别是抗生素带来的负面效应,它是无污染、无残留、抗疾病、促进动物生长的天然添加剂,在饲料工业中得到了广泛的应用.本文以豆豉为原料,分离鉴定出了KT-1,KT-4,KT-9和KT-14四株纳豆芽孢杆菌菌株,同时依据菌株在使用过程中应具备的几个基本条件,从四种菌株中筛选出了对温度、pH、抗生素有较强耐受性;对病原菌有强抑制能力和对有益菌有良好共生能力;同时又具有较好产蛋白酶、淀粉酶和纤维素酶能力的优良益生菌纳豆芽孢杆菌菌株KT-9.     

产蛋白酶菌株的鉴定及其对虾壳的脱蛋白研究

从虾塘沉积物中分离到一株产蛋白酶的菌株C1,采用菌落形态、生理生化特征和16S rDNA基因序列分析相结合的方法进行鉴定,进一步探究其在提取虾壳甲壳素工艺中脱蛋白的应用,并与枯草芽孢杆菌（Bacillus subtilis）对虾壳蛋白脱除效果进行比较分析。结果表明,菌株C1被鉴定为一株蜡样芽孢杆菌（Bacillus cereus）,其对虾壳的脱蛋白能力高于枯草芽孢杆菌。当发酵培养基中葡萄糖添加量为50 g/L,虾壳粉添加量为20 g/L,酵母膏添加量为1 g/L时,枯草芽孢杆菌和蜡样芽孢杆菌发酵5 d的蛋白酶活力分别为145.7 U/mL、220.8 U/mL,脱蛋白率分别达到80.4%、90.8%。     

枯草芽孢杆菌对杂交鲤鱼生长性能的影响

研究饲料中添加枯草芽孢杆菌对黄河鲤鱼(♂)与建鲤(♀)杂交F1生长性能的影响。结果表明:随着枯草芽孢杆菌添加水平的提高,试验组末体重、增重率和特定生长率提高,饵料系数降低;枯草芽孢杆菌水平在6.0×108 cfu/kg时的末体重、增重率和特定生长率最大,饵料系数最低,且与对照组相比差异显著(P<0.05);但枯草芽孢杆菌水平提高到8.0×108 cfu/kg时的末体重、增重率和特定生长率反而降低,饵料系数却增加。适宜的水平为4.79×108～5.27×108 cfu/kg。