首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
一株产乳酸链球菌肽菌株SM526的分离鉴定及生理特性研究   总被引:2,自引:0,他引:2  
自包头市售酸酪中分离出一株链球菌SM526,菌体多为长链球状,革兰氏染色阳性,抗酸染色阴性,兼性厌氧生长,最适生长温度为30℃,无芽孢,英膜及鞭毛,不运动,可从多种糖类产酸,但不产气,接触酶阴性,精氨酸双水解酶阳性,不液化明胶,还原石蕊牛奶并凝固,DNA中G+C为38.5mol%,经鉴定,SM526菌株为乳酸链球菌(Streptococcuslactis)经用牛津杯琼经扩散法检测制或杀死包括芽孢杆  相似文献   

2.
从新鲜牛乳中分离得到乳酸菌X4。该菌株在发酵过程中产生的乳酸菌素有较广的抑菌谱,不仅对芽孢杆菌、葡萄球菌、链球菌等革兰氏阳性细菌的生长具有较强的抑制作用,而且对大肠杆菌、沙门氏菌等革兰氏阴性细菌的生长也具有较强的抑制作用。经鉴定,X4 菌株为乳脂链球菌(Streptococcus crem oris sp.X4)。  相似文献   

3.
乳酸链球菌素是一种安全、高效、无毒且应用广泛的天然食品防腐剂,是一些乳酸链球菌菌株产生的一种多肽抗生素,它对许多革兰氏阳性菌,包括利斯特氏菌属、按菌属、葡萄球菌属和芽抱杆菌属在内的多种腐败菌和食物病原菌有强烈的抑制作用,而对酵母菌和霉菌无任何作用。乳酸链球菌是一种34肽,分子量为3510。在酸性条件下较稳定,溶解性也较好。人们对其研究至今已有60多年的历史。1969年,FAO/WHO食品添加剂联合专家委员会对乳酸链球菌素给予了国际性认可,迄今为止,乳酸链球菌素已被50多个国家和地区广泛地应用于乳制品、罐头食品、…  相似文献   

4.
透明质酸产生菌的诱变育种及发酵条件   总被引:6,自引:0,他引:6  
本文研究了透明质酸(HA)产生菌的诱变育种及摇瓶发酵条件。以兽疫链球菌(Streptococcuszoepidemiccus)NCT6180为出发菌种,在普通加血培养基上研究了HA的产生能力,用正交法研究了野生菌的最佳培养条件,通过单菌落分离得到野生高产菌株。再通过紫外和NTG诱变得到溶血性较弱的菌株,部分菌株比出发菌株产量提高一倍以上。在摇瓶条件下,PH值的控制及葡萄糖的加入均有利于HA的产生。  相似文献   

5.
从奶粉中分离到一株同型乳酸发酵杆菌,编号TQ33,主要特点:产生芽孢,生长温度范围(20~63)℃,最适生长温度(45~50)℃,接触酶试验阳性,通气条件下生长良好,厌氧条件下发酵葡萄糖产酸不产气,主要产L(+)乳酸,菌体(G+C)为(32.45)%,生理生化性质特殊,据以上特点,将TQ33菌株鉴定为凝结芽孢杆菌(Bacilluscoagulans),LD_(50)试验表明,菌体和代谢产物属无毒物质。  相似文献   

6.
云南程海螺旋藻养殖池中细菌研究   总被引:3,自引:0,他引:3  
对程海螺旋藻玻璃温室-半封闭跑道式循环环境池中的细菌进行了研究,结果发现,细菌总数通常为10^4-10^7个/mL,并且随培养时间呈一定规律性波动;池子报废与细菌总有一定关系,与藻种抗逆性及水环境的富营养化关系更大;经鉴定,优势菌为奈瑟氏球菌属(Neisseria)、葡萄球菌属(Staphylococcus)微球菌属 (Micrococcus)、肠杆菌科(Enterobacteriaceae)等;少数菌株能明显抑制或促进螺旋藻生长,主要是通过其代谢产物作用于藻体;对5株菌有明,其最适生长温度为37℃或25-37℃,PH7-9,与程海水环境相适应。  相似文献   

7.
从中国石龙子(Eumeces chinensis)胃、小肠和大肠中分离出的细菌包括枸橼酸杆菌属的弗劳地枸橼酸杆菌(Citrobacter freundii)和异型枸橼酸杆菌(Citrobacter diversus)、变形杆菌属的奇异变形杆菌(Proteus mirabilis)、肠杆菌属的阴沟肠杆菌(Enterobacter cloacae)、芽孢杆菌属的枯草芽孢杆菌(Bacillus subtilis)、葡萄球菌属的表皮葡萄球菌(Staphtlococcus epidermidis)和类杆菌属普通类杆菌(Bacteroides vulqatus).细菌在胃、小肠和大肠中分布数量为3.42x10~6、2. 04 x 10~6和 1. 11x 10~9.弗劳地枸橼酸杆菌为优势菌群.分离出的霉菌属于青霉属(Pencillium)、曲霉属(Aspergillus)和毛孢子菌属(Trichosporon),主要是青霉属。在胃、小肠和大肠中霉菌的数量分别是2.19x10~4、1.67x10~4和1.61x10~4,酵母菌和放线菌都未发现.  相似文献   

8.
认为榆叶梅不与Amygdalusulmifolia(Franch.)M.Popov同种,而与毛樱桃Cerasustomentosa(Thunb.)Wall.特别相近,且较毛樱桃进化,其系统位置应属于樱属CerasusMill.、矮生樱亚属Subgen.Microcerasus(Koehne)YuetLi、管萼组Sect.AmygdalocerasusKoehne.其学名应为Cerasustriloba(Lindl.)Bar.etLiou.  相似文献   

9.
硝基苯好氧降解菌的驯化和筛选   总被引:9,自引:0,他引:9  
本文选用东北制药总厂深井曝气池中活性污泥作为菌源,以硝基苯为底物,在好氧条件下,经过长时间的驯化筛选,成功地分离出了6株对硝基苯有较强耐受力的优势菌株,经鉴定为:芽孢杆菌属(Bacilus),假单胞杆菌属(Pseu-domonas)微球菌属(Micrococcus)短小杆菌属(Breribacterium),研究结果表明,在好氧条件下它们对硝基苯有较好的生物降解能力.  相似文献   

10.
为了改良和利用盐碱地,以秋茄(Kandelia obovata)和木榄(Bruguiera gymnorhiza)为原材料,对耐盐内生细菌进行分离 并鉴定。 结果表明:从 2 种植物的根、茎、叶中初步分离出耐盐的内生细菌 96 株,均为革兰氏阳性菌;提取各菌株的 DNA 并扩 增其 16S rDNA 序列,以 HinfⅠ、HaeⅢ、MspⅠ和 TaqⅠ4 种酶进行酶切,并统计遗传型,选取不同组合类型的代表菌株进行 16S rDNA序列测定,通过 BLAST 比对分析并利用 MEGA 软件建立发育树等分子鉴定手段初步推断,所分离的内生细菌分别 为越南芽孢杆菌(Bacillus vietnamensis)、阿耶波多氏芽孢杆菌(Bacillus aryabhattai)、芽孢杆菌属(Bacillus sp.)、白翎芽孢杆菌 (Bacillus baekryungensis)和巴氏葡萄球菌(Staphylococcus pasteuri);对这 5 种菌的脱氨酶活性进行测定,越南芽孢杆菌的值最高。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号