共查询到20条相似文献,搜索用时 62 毫秒
1.
采用离心、过滤、浓缩、葡聚糖凝胶柱层析等方法对热杆菌素YN8674进行了初步纯化,经聚丙烯酰胺凝胶电泳检测初步纯化样品还有两条谱带。研究了初步纯化样品对热、4℃贮存期、pH和用五种酶处理后的剩余活性,结果表明,热杆菌素YN8674是一种极其稳定的抑菌物质,经121℃、15磅高温高压处理30min后还残存3.1%的活力,抑菌圈仍清晰可见;4℃冰箱中贮存60d,其活性几乎不受损失;经核糖核酶、纤维素酶 相似文献
2.
一株产耐热碱性脂肪酶芽孢杆菌的筛选及其所产酶性质的研究 总被引:4,自引:0,他引:4
李春华 《湖北大学学报(自然科学版)》1999,21(3):294-296
从武汉市白沙洲沙鸥食用油总厂分离筛选到一株耐热碱性脂肪酶的产生菌,经鉴定为产邪包的短杆菌、革兰氏阳性、该菌株的最适生长温度为45℃,所产酶的最适作用温度为60℃,最适PH为10.0,且PH在8.0-11.0范围内酶蛋白性质稳定。 相似文献
3.
采用严格的 Hungate 厌氧技术,从云南省腾冲高温温泉污泥样品中分离一株嗜热自养产甲烷杆菌 YT-7菌株。该菌株细胞呈长杆状,不运动,不形成芽孢,革兰氏染色阳性。在65—70℃下培养时菌体为0.3-0.4×1.5-13μm。分离物仅能利用 H_2/CO_2为能源和碳源,在无机盐液体培养基中生长,细胞最小倍增时间为3.2小时。滚管菌落呈灰白色,半透明,近圆形;落射荧光显微镜检查呈蓝绿色或黄绿色荧光。YT-7菌株的最适生长温度为65—70℃,低于45℃或高于75℃不生长。最适生长 pH 为6.5—7.0。根据形态和生理性状的研究,分离物暂定嗜热自养产甲烷杆菌 YT-7(Methanobacterium thermoautotrophicumYT-7)。 相似文献
4.
酵母菌耐热性的最适热激条件研究 总被引:2,自引:0,他引:2
以安琪抗高温酵母菌YY为研究材料,采用30-48℃的不同温度和10~180min不同的时间对酵母菌进行热激诱导产生耐热性的研究,研究表明最适热激温度为42℃,最适热激时间为30min,产生耐热性后,在50℃处理的时间越长,活力越小,在酵母菌的不同生长时期,菌体达到一定的浓度后,耐热性的产生没有显著影响,从28℃升到热激温度42℃所需时间在30-240min内,时间越长产生的耐热性越强。 相似文献
5.
研究了生物肥功能菌——地衣芽胞杆菌1.934 (Bacillus licheniformis)培养条件对菌体生长量的影响.采用了单因素实验和响应曲面法(RSM)设计实验和分析数据.获得了菌体摇瓶培养的最适条件:培养温度35℃,转速为150r/min,接种量为3.6%,pH为7.5.地衣芽孢杆菌在最适条件下培养约20h,淀粉酶的酶活最高,活力可达12.7U/mL培养液.培养约27h得到最大的菌体收益. 相似文献
6.
《华东理工大学学报(自然科学版)》2016,(1)
为克服市售冻干粉批次间活性差异较大、检测前需复苏等缺点,对明亮发光杆菌从摇瓶到发酵罐进行逐级放大培养,探索其在发酵罐上的最适连续培养条件,获得连续稳定的发光细菌检测液。在摇瓶条件下得到的最适培养条件为:温度18℃,初始pH=7.0,转速200r/min,接种量2%。在此条件下,菌体最大比发光度可达2 500mV。在5L发酵罐中的最适培养条件为:转速200r/min,通气量0.5vvm,稀释率0.10h-1。在此条件下,对明亮发光杆菌进行多批连续培养,菌体比发光度可稳定在500~1 000mV,可连续培养10d左右。 相似文献
7.
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
8.
带鱼内脏蛋白酶的性质 总被引:4,自引:0,他引:4
郭彩华 《集美大学学报(自然科学版)》1997,2(2):58-61
带鱼内脏提取液的蛋白酶活力,在PH2.2 ̄9.0之间有三个峰值出现,这说明提取液中存在酸性(最适PH为3.6)、中性(最适PH为6.8)及碱性(最适PH为8.4)蛋白酶;这三类蛋白酶在作用时间为30min时,最适温度分别为50℃,50 ̄60℃,50 ̄60℃,温度对酶水解速度影响很大,内脏蛋白酶在0℃的水解速度是最适温度的1.75% ̄2.71%。NaCl,FeCl3,ZnSO4,CaCL2,EDTA 相似文献
9.
采用单因素实验研究实验室分离的氧化亚铁硫杆菌的生长特性.通过测定培养过程中吸光度、Fe2 浓度和总Fe浓度的变化,计算Fe2 氧化速率,研究初始pH值、初始接种量和温度对细菌生长的影响.结果发现,该氧化亚铁硫杆菌在接种初期,生长缓慢,对Fe2 的氧化速度较慢,12h后繁殖速度加快,氧化速率开始增加,27h后对Fe2 的氧化速率达最大值0.52g/(L.h),30h后Fe2 转化率接近100%;适宜于该氧化亚铁硫杆菌生长和代谢的初始pH值为2.30,接种量为10%,培养温度为28℃. 相似文献
10.
双歧杆菌与嗜热链球菌混菌培养研究 总被引:1,自引:0,他引:1
研究了短双歧杆菌(Bifidobacteriumbreve)和嗜热链球菌(Streptococcusthermophihus)的选择性培养条件,探讨了两菌在单一菌种培养和混菌培养状况下的菌体生长和产酸特点,发现该两菌种之间的生长及产酸存在着明显的互相促进作用,在牛乳培养基中混菌培养状况下两菌的生长及产酸代谢均优于单菌种培养.在两菌的接种量体积分数各为1%的条件下,不但能获得较高的活菌数,而且凝乳状态及风味都比较好. 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.
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.
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well. 相似文献
14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation. 相似文献
15.
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
16.
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
17.
Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
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
18.
Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
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
19.
Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
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
20.
《上海师范大学学报(自然科学版)》2014,(5):550
<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