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紫花苜蓿根腐病原菌——拟枝孢镰刀菌的鉴定及其生物学特性研究 总被引：2，自引：0，他引：2
《草业学报》2015,(10)
本文对从内蒙古赤峰巴雅尔草业基地紫花苜蓿根部分离到的菌株BYE27-2-5进行了致病性测定、形态学和r DNA-ITS序列分析鉴定及生物学特性测定。结果表明,该菌菌丝生长、产孢和孢子萌发的最适温度分别为25,30和28℃;p H值5.0~11.0均宜于菌丝生长,产孢最适p H 8.0,孢子萌发最适p H 7.0;光暗交替利于菌丝生长,光照利于产孢和孢子的萌发;孢子在相对湿度低于75%不萌发,高于95%萌发较快;葡萄糖蛋白胨培养基利于菌丝生长和孢子萌发,马铃薯蔗糖琼脂培养基利于产孢;碳源中葡萄糖利于菌丝生长和孢子萌发,蔗糖利于产孢;氮源中蛋白胨利于菌丝生长,酵母膏利于产孢和孢子萌发;菌丝致死温度为54℃(10 min),分生孢子的致死温度为48℃(10 min);根据其形态特征和r DNA-ITS序列分析结果,鉴定其为拟枝孢镰刀菌(Fusarium sporotrichioide)。 相似文献
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以分离自青海省海晏县病死羊脏内的一株B型诺维氏梭菌株为研究对象,通过不同培养基、不同p H及不同培养时间等进行产毒比较试验证明,该菌在含1.0%葡萄糖培养基,p H 8.0~8.4,37℃培养72h产毒达最高点,平均可达2万MLD/m L,最高可达4万MLD/m L;利用该菌株制成羊黑疫单价疫苗,并以标准菌株菌苗作为对照,完成了家兔免疫攻毒、血清抗体测定;羊免疫血清抗体测定及高免血清的制备等试验。试验结果表明,该疫苗0.1m L免疫家兔21d,可抵抗200MLD(家兔最小致死量)毒素的攻击,是现用疫苗的2倍,0.1m L家兔免疫血清可中和300MLD(小白鼠最小致死量)的毒素,是现用疫苗的3倍,羊免疫14d,血清0.1m L可中和400 MLD(小白鼠最小致死量)的毒素,180d时血清0.1m L可中和50MLD的毒素,用此疫苗免疫家兔制备的抗血清每m L可中和160000MLD毒素。该菌株在筛选的培养基上具有良好的产毒性能,制备的羊黑疫疫苗免疫效果明显优于标准菌株菌苗,可作为羊黑疫疫苗生产用菌株。 相似文献
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中华鳖温和气单胞菌口服缓释微球疫苗的研究:疫苗用菌液培养条件的优化 总被引：3，自引：3，他引：3
以中华鳖温和气单胞菌 (Aeromonas sobria,As)口服缓释微球疫苗生产菌株 Z- 1株培养菌液含菌量和胞外产物溶血性为指标 ,考察了培养温度、培养时间、振荡与否、培养基 p H等因素对 As Z- 1株繁殖和产毒的影响 ,并采用正交试验方法 ,对培养基配方进行了优化试验。结果表明 :不同的培养温度、培养时间、振荡与否、培养基 p H等均会影响As Z- 1株的菌体产量和溶血性 ,其中 2 8℃振荡 (2 0 0 r/ min)培养 36 h菌液的含菌量和溶血价均较高 ;在营养肉汤中添加适量的硫酸铜、磷酸二氢钾、硫酸锰和硫酸铵 ,可显著提高菌液的含菌量和溶血价。 相似文献
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植酸酶高产菌Px培养基的筛选和优化 总被引：1，自引：0，他引：1
本文利用Plackett-Burman设计筛选出培养基中影响植酸酶高产菌Px产酶的重要因素,然后利用正交试验加以优化。结果表明,植酸酶高产菌株Px的最适培养基组成为:蛋白胨0.2%、葡萄糖3%、MgSO·47H2O0.05%、MnSO·47H2O0.003%、FeSO4·7H2O0.003%、植酸钠0.15%、硫酸铵0.3%、氯化钾0.1%、pH值为5.5。 相似文献
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《中国草食动物科学》2016,(3)
为探究温度和p H值对酿酒酵母菌生长特性的影响,采用单因素实验设计,检测了不同温度、不同初始p H值对酿酒酵母菌生长的影响。结果表明,培养基p H值和温度对酿酒酵母菌的生长具有明显的影响,当p H值为3.0或者8.0,温度为20℃或高于40℃时,酿酒酵母菌的生长明显受到抑制;酿酒酵母菌在培养基初始p H值为4.0~6.0,温度在25~30℃时生长良好。 相似文献
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桑褐斑壳丰孢(Phloeospora maculans)是近几年鉴定的云南蚕区桑园发生桑褐斑病的主要病原菌之一。采用菌丝生长速率法研究不同培养基及碳源和氮源、p H值、温度、光照条件对该病原菌菌丝生长与产孢量的影响。结果表明,桑褐斑壳丰孢的菌丝适宜在PDA培养基和PDA+1%桑叶碎片培养基(简称PDA桑叶培养基)上生长,其中PDA桑叶培养基是最佳的产孢培养基;菌丝生长最佳培养基中的碳源和氮源物质分别是麦芽糖、蛋白胨,以可溶性淀粉为碳源的培养基产孢量最大,而在所有有氮源和无氮源物质的培养基上均不产孢;菌丝生长的最适培养基p H值为6~9,而p H 6时产孢量最大;在22~28℃培养条件下,菌丝生长最快,产孢量最大;连续黑暗条件适合菌丝生长和产孢;菌丝的致死温度条件为50℃水浴处理10 min。上述研究结果提示桑褐斑壳丰孢有很强的营养利用和环境适应能力。 相似文献
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《饲料工业》2015,(15)
文章旨在对角蛋白酶产生菌Bacillus subtilis A1-2菌株的发酵产酶条件进行优化。以发酵液上清中的角蛋白酶活力为检测指标,利用单因素试验和正交试验相结合的方法优化该菌株摇瓶发酵产角蛋白酶的最适诱导物、碳氮源、无机离子、表面活性剂及最佳培养基配方与发酵参数。获得Bacillus subtilis A1-2菌株的液体深层发酵产角蛋白酶条件如下:培养基配方为玉米粉3.0%,黄豆饼粉3.0%,80目羽毛粉3.0%,Ca Cl 2 0.5%,表面活性剂吐温-80 0.5%;最优发酵参数为:培养基起始p H值8.0,250 ml三角瓶中装液量30 ml,发酵温度37℃,接种量6.0%,发酵60 h;此条件下该菌株角蛋白酶活力达642.1 U/ml,相比优化前的初始酶活力328.5 U/ml提高了95.46%。本研究结果为该菌用于角蛋白资源的开发利用奠定了基础。 相似文献
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为探究改良Frey氏液体培养基质控菌CVCC2960滑液支原体(以下简称MS)生长规律,本试验首次同时采用CFU计数、CCU测定和p H值测定的方法,比较不同接种浓度、接种体积和不同代次MS生长情况。结果显示:5%与10%接种量的CCU测定结果峰值差异不明显,但5%接种的CFU计数峰值更高,pH下降更慢;1~5代菌在生长曲线各阶段的测定结果均无明显差别;3种不同接种方式的测定结果显示,用0.5 m L菌液接种9.5 m L培养基的方式更利于MS生长。本试验为改良Frey氏液体培养基的质控标准化提供依据。 相似文献
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采集红嘴鸥的粪便并进行细菌分离培养,首次分离到产酸克雷伯菌。红嘴鸥产酸克雷伯菌在普通琼脂、麦康凯、伊红美蓝（EMB）、营养肉汤及SS琼脂培养基上均可生长,多数为单个存在或两两相连,少数依傍聚堆成锯齿状排列。本菌为无鞭毛、无芽孢的革兰氏阴性杆菌,能利用葡萄糖（产酸产气）、可发酵乳糖、甘露醇、麦芽糖及蔗糖;靛基质试验为阳性,MR阴性,VP试验阳性,不产生H2S,可利用尿素及西蒙氏柠檬酸盐,但半固体琼脂（动力）试验为阴性;本菌对氧氟沙星最为敏感;小白鼠对本菌易感,且腹腔接种易感性高。 相似文献
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试验旨在筛选长白山原始森林土壤中耐胁迫生长能力强、产酸能力强、体外抑菌特性好的耐低温乳酸菌,并对其相关生物学特性进行分析,为东北地区寒冬季节低温青贮提供优良乳酸菌菌种资源。采用低温（10℃）进行耐低温乳酸菌初筛,经不同pH、温度及盐度等条件下进行乳酸菌生长特性测定后,进行候选菌株的种属鉴定,并对候选菌株进行生长曲线、产酸曲线、耐酸和耐胆盐性能、抑菌性能测定及小鼠饲喂试验。结果显示,通过10℃低温条件培养,初筛获得11株能够良好生长的耐低温乳酸菌,其中C37、C34和C4212经16S rRNA测序分析后鉴定为植物乳杆菌,在培养7 d时,pH均可下降至4.25以下,均能够在4℃、45℃、pH 3.0、6.5% NaCl等条件下良好生长。生长曲线分析发现,3株乳酸菌均在4 h达到对数生长期,10~12 h后进入生长稳定期。在培养24 h时,C37、C34和C4212可将pH分别降至4.04以下,在pH 3.0条件下,C37和C4212具有较高的存活率,且对0.5%胆盐具有一定的耐受性,其存活率均在80%以上。对常见病原菌体外抑菌表明,3株乳酸菌对产肠毒素大肠杆菌、鼠伤寒沙门氏菌、金黄色葡萄球菌及肠炎沙门氏菌均有抑制作用,小鼠饲喂试验表明生物安全性好。本试验结果表明,从长白山原始森林土壤中筛选和鉴定出的乳杆菌C37、C34、C4212可作为东北地区寒冬季节低温青贮优良乳酸菌菌种资源。 相似文献
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The purpose of the experiment was to screen psychrotrophic lactic acid bacteria with strong stress-resistant growth ability,acid production ability and good bacteriostatic characteristics in vitro,and analyze its related biological characteristics,so as to provide excellent psychrotrophic lactic acid bacteria resources for low temperature silage in Northeast China.The culture condition of 10 ℃ was used to screen the psychrotrophic lactic acid bacteria.After the determination of the growth characteristics of Lactobacillus under different pH,temperature and salinity conditions,the species identification of the candidate strains was carried out,and the growth curve,acid production curve,acid and bile salt resistance,bacteriostatic performance and feeding test of mice were conducted for the candidate strains.The results showed that 11 strains of psychrotrophic lactic acid bacteria could grow well at 10 ℃.The strains C37,C34 and C4212 were identified as Lactobacillus plantarum by 16S rRNA sequencing analysis.The pH of C37,C34 and C4212 decreased to below 4.25 after 7 days of culture.In addition,C37,C34 and C4212 could grow well at 4 ℃,45 ℃,pH 3.0 and 6.5% NaCl.The analysis of growth curve showed that the three strains of Lactobacillus all had a fast growth rate,entered the logarithmic growth period at 4 h,and entered the stable growth period in 10-12 h after inoculation.In the aspect of acid production rate,C37,C34 and C4212 could reduce pH below 4.04 at 24 h of culture.At pH 3.0,C37 and C4212 had a high survival rate,they all had a certain tolerance to 0.5% bile salt,and the survival rate was more than 80%.C37,C34 and C4212 had inhibitory effect on enterotoxin producing Escherichia coli,Salmonella Typhimurium,Staphylococcus aureus and Salmonella Enteritis,and the animal test of three Lactobacillus plantarum were safe.Based on the results of this experiment,Lactobacillus C37,C34 and C4212 were screened and identified from the forest soil of Changbai Mountain,which could provide excellent lactic acid bacteria resources for low temperature silage in winter in Northeast China. 相似文献
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红豆草黑腐病菌菌丝生长和产毒培养条件的优化 总被引：4，自引：2，他引：2
从红豆草自然发生的黑腐病病斑上分离得到细链格孢菌(Alternaria tenuis)菌株,对该病菌的菌丝生长及其产毒条件进行了研究。结果表明,病原菌在供试的6种培养液中均能生长并且产毒,但在PSK培养液中生长及产毒最好;在1-19d的培养时间内该病菌均可以生长及产生毒素,而在13 d时菌丝生长量及其产毒能力均达到最大,菌丝生长与产毒能力间显著正相关;该病原菌在5-40℃的范围内均可生长并产生毒素,但菌丝生长的最适温度为25℃,而最适合产毒的温度为15℃;在pH值为3~11的范围内,该病菌均能生长并产毒,而且偏酸性条件有利于菌丝的生长及其毒素的产生,菌丝生长和产毒的最佳pH值分别为4和6。 相似文献
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Factors affecting conjugated linoleic acid and trans-C18:1 fatty acid production by mixed ruminal bacteria 总被引：2，自引：0，他引：2
The objective of this study was to identify environmental factors that influence conjugated linoleic acid (CLA) and trans-C18:1 fatty acid production by mixed ruminal bacteria. Ruminal contents were collected from a 600-kg ruminally fistulated Hereford steer maintained on pasture. Mixed ruminal bacteria were obtained by differential centrifugation under anaerobic conditions and added to a basal medium that contained a commercial emulsified preparation of soybean oil and a mixture of soluble carbohydrates (cellobiose, glucose, maltose, and xylose). Culture samples were collected from batch culture incubations at 0, 2, 4, 6, 8, 12, 24, 26, 28, 30, 32, and 48 h. Continuous culture incubations were conducted at dilution rates of 0.05 and 0.10 h(-1) with extracellular pH values of 5.5 and 6.5, and 0.5 and 1.0 g/L of mixed soluble carbohydrates. Culture samples were obtained from the culture vessel once steady-state conditions had been achieved. In batch culture, trans-C18:1 concentrations increased over time and reached a maximum at 48 h. Little CLA was produced during the first 8 h, but cis-9, trans-11 CLA concentrations remained high between 24 and 30 h. When mixed ruminal bacteria were maintained in continuous culture on 0.5 g/L of mixed soluble carbohydrates, concentrations of trans-C18:1 and cis-9, trans-11 CLA were reduced (P < 0.05) at a dilution rate of 0.05 h(-1) and an extracellular pH of 5.5. Similar effects were also observed when 1.0 g/L of mixed soluble carbohydrates was used. When extracellular pH was lowered to 5.0, neither trans-C18:1 or CLA isomers were detected. In conclusion, our results suggest that culture pH appears to have the most influence on the production of trans-C18:1 and CLA isomers by mixed ruminal bacteria. 相似文献
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D R Hyatt J C Galland J R Gillespie 《Journal of veterinary diagnostic investigation》2001,13(1):71-73
The performance of a commercially available enzyme immunoassay (EIA) for determining the presence of Shiga toxin I and II in human diarrheal stool samples was evaluated for use as a presumptive test for the presence of Escherichia coli O157:H7 in nondiarrheal bovine fecal samples collected from 10 Kansas cow-calf ranches. The prevalence of E. coli O157:H7 in 2,297 samples, as determined by selective bacterial culture, was 1.6%. The sample prevalence of non-E. coli O157:H7 Shiga toxin-producing bacteria, as detected by the Shiga toxin EIA, was 5.8%. Only 2 of 136 samples that tested positive with the Shiga toxin EIA were positive for E. coli O157:H7 by culture. Compared with bacterial culture, the sensitivity of the Shiga toxin EIA was 5.5% and the specificity was 94.1%. Agreement between the 2 tests, as measured by the kappa statistic, was poor (kappa = -0.002). Although the Shiga toxin EIA was not a good presumptive test for the determination of E. coli O157:H7 in bovine fecal samples because of its low sensitivity (5.5%), it might be a useful test for the detection of Shiga toxin producing non-E. coli O157:H7 organisms in bovine feces. 相似文献
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【目的】试验旨在研究植物乳杆菌GX20200417-1菌株的生物学特性及体外抑菌活性,探讨其在生产中应用的可能性。【方法】将植物乳杆菌GX20200417-1菌株接种至不同pH和含不同浓度胆盐的PBS,以及人工胃肠液中,使用菌落计数分析其对酸、胆盐和人工胃肠液的耐受性。使用牛津杯法检测GX20200417-1菌株对大肠杆菌、金黄色葡萄球菌及沙门氏菌的抑菌能力;通过与霉菌毒素共培养后使用ELISA方法研究GX20200417-1菌株对霉菌毒素的降解能力,并饲喂小鼠进行安全性试验。【结果】植物乳杆菌GX20200417-1菌株能够耐受pH 2.0及0.3%胆盐,并在人工胃肠液中有至少1×104 CFU/mL的活菌数;GX20200417-1菌株发酵上清液对大肠杆菌、沙门氏菌、金黄色葡萄球菌均有明显的抑制作用,对玉米赤霉素及黄曲霉毒素均有降解作用,但对呕吐毒素无降解作用;灌服GX20200417-1菌株后小鼠安全、无毒副作用。【结论】植物乳杆菌GX20200417-1菌株具有优良的益生特性,在畜禽生产中有一定的开发潜力。 相似文献
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对植物乳杆菌(Lactobacillus plantarum)8-6产细菌素的发酵条件进行了优化,分别研究了培养时间、温度、接种量、培养基起始pH值、培养基碳源、氮源等因素对细菌素产生的影响,通过单因素水平试验和正交试验,确定产细菌素的最佳培养基组合和最佳发酵条件为葡萄糖3%,胰蛋白胨2%,蛋白胨1%,酵母膏1%,硫酸镁0.058%,吐温-80 0.2%,30℃培养24h,培养基起始pH值为6.5,接种量2%。乳杆菌8-6优化后效价为1825.56IU/mL,比优化前提高了373.15%。 相似文献
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Effect of growth conditions on the Streptococcus bovis phosphoenolpyruvate glucose phosphotransferase system. 总被引：1，自引：0，他引：1
Four strains of the ruminal bacterium Streptococcus bovis were surveyed for phosphoenolpyruvate (PEP) and ATP-dependent phosphorylation of glucose and the nonmetabolizable glucose analog 2-deoxyglucose. All four strains had high rates of glucose phosphorylation with either phosphoryl donor, but 2-deoxyglucose activity was much higher in the presence of PEP. These results provide evidence for a PEP-dependent glucose phosphotransferase system in these bacteria. Mannose and 2-deoxyglucose inhibited PEP-dependent phosphorylation of glucose by S. bovis JB1 by 50 and 38%, respectively, whereas alpha-methylglucoside had little effect. Mannose was a competitive inhibitor of PEP-dependent phosphorylation of glucose with an inhibition constant of 2.8 mM, and PEP-dependent activity in cells grown in batch culture was optimal at pH 7.2. When S. bovis JB1 was grown in continuous culture, PEP-dependent phosphorylation of glucose and 2-deoxyglucose was highest in cells grown at a dilution rate of .10/h and at low glucose concentrations. Phosphoenolpyruvate-dependent activity was optimum at a growth pH of 5.0 for cells grown in medium that contained less than 6.0 g/liter of glucose. These data indicate that PEP-dependent glucose phosphotransferase system activity can be influenced depending on the growth conditions used to culture S. bovis. Furthermore, these results suggest that environmental conditions within the rumen will affect how glucose is transported by S. bovis. 相似文献
20.
为提高猪链球菌(S.suis)疫苗的高密度发酵效果,本研究对S.suis疫苗株(ST171)的发酵过程进行检测,利用外源添加试验研究乳酸对ST171发酵的影响,并通过对发酵工艺的优化减少乳酸的生成.结果表明,ST171发酵液中积累有大量对其生长及活菌数量有不利影响的代谢副产物乳酸.经优化确定ST171发酵的最优工艺参数为:溶氧水平20％,初始葡萄糖浓度10g/L,残糖浓度1g/L,最大比生长速率小于0.7 h-1.在优化条件下,发酵过程中乳酸生成量与原工艺相比降低了41.41％,菌体生物量和活菌数量分别提高了70.58％、129.09％,取得了良好的发酵效果. 相似文献