共查询到20条相似文献，搜索用时 281 毫秒
1.
为寻找高产琼胶酶的微生物新资源,促进琼胶低聚糖的研究与开发,本研究自多个土壤样品中进行微生物的分离,借助于卢戈氏碘液染色法进行琼胶酶生产菌的筛选,通过DNS-还原糖测定比较不同微生物的产酶特性,克隆、分析细菌的16S rRNA基因序列进行分子鉴定。最后得到1株胞外琼胶酶活性较高的土壤细菌,鉴定至Paenibacillus属,命名为MY03菌株;分子鉴定表明Paenibacillus sp. MY03是产琼胶酶细菌家族中的新成员。 相似文献
2.
通过三株红假单胞菌在不同碳源、氮源、pH值和不同温度等条件的混菌培养实验，筛选出适合其生长的最适碳源、氮源、pn值和培养温度、试验结果表明：该混合菌株在乙醇、丙酸钠、乙酸钠等5种碳源中，以乙酸钠为最适碳源；在氯化铵、硫酸铵等5种无机氮源中，以硫酸铵为最适氮；最适pH为8．5；最适培养温度为38℃。 相似文献
3.
研究了碳源和氮源种类、碳源浓度以及起始pH值对假丝酵母Candidasp。菌株发酵生产脂肪酶的影响。结果显示,最适碳源为橄榄油,氮源为酵母膏,橄榄油浓度为2％,起始pH值为6.0。应用响应面试验设计对酵母膏、橄榄油和起始pH值进行培养基优化,结果表明,优化后的培养基配方为：橄榄油2.582％,酵母膏0.276％,K2HPO4 0.1％,MgSO4·7H2O 0.01％,NaCl 0.05％,pH6.28。在此条件下,假丝酵母Candidasp.液体发酵液中脂肪酶的酶活力可达36250U·mL^-1。 相似文献
4.
通过测定几丁质酶活力的方法对来源于不同寄主和采集地的16株玫烟色棒束孢进行筛选,获得活性较高菌株RCEF3304,并对高活力菌株RCEF3304产几丁质酶的pH值、装液量、接种量和温度等发酵条件进行优化研究。结果表明高酶活菌株产酶最适条件:胶体几丁质2%,NaNO33%,Mg2+0.05%,培养基初始pH值6.0,接种量12%,100 mL装液量为10 mL,温度25℃和培养时间36 h;最适发酵工艺条件下,几丁质酶酶活OD值达到0.486,比优化前发酵水平提高了128%。 相似文献
5.
本研究主要从清除超氧阴离子自由基功能、清除羟自由基功能及抗DPPH自由基能力测试来评价香菇胞外多糖抗氧化功能。在浓度为0.30mg·m L-1条件下,香菇胞外多糖对羟自由基、DDPH自由基的清除率分别为76.23%和62.58%,而如果浓度为0.25mg·mL-1,香菇胞外多糖能将68.12%的超氧阴离子自由基清除。实验结论最终表明,其抗氧化能力比较突出。此外,对香菇胞外多糖的抑菌活性及其抑菌稳定性进行了研究。结果证实:酸碱度值如果处在5-9之间,香菇胞外多糖则全面存在着抑菌活性,其中最强抑菌活性发生在酸碱度值pH=6时。结果证实,该菌株的酸碱抑菌谱比较广。而且这种香菇胞外多糖的热稳定性能较好,121℃条件下30min处理,抑菌活性依然不会受到明显影响。香菇胞外多糖的生化特征良好,有效奠定了其未来的发展与应用基础。 相似文献
6.
朱德艳 《荆门职业技术学院学报》2009,24(5):29-32
介绍了一种从土壤中选育一株产环糊精葡萄糖基转移酶（CGTase）的芽孢杆菌的方法。经筛选,最终找到一株高产CGTase的菌株SC3—2,鉴定该菌株为嗜碱性枯草芽孢杆菌。通过对其产酶条件的探索,结果表明：以玉米淀粉为碳源,以黄豆粉为氮源,在pH值为6．5,30℃的条件下培养36h,菌株所产CG-Tase的酶活力可迭5046U／mL。 相似文献
7.
通过单因子实验,筛选得到了适合大豆疫霉拮抗细菌B048液体发酵的最佳碳源为玉米粉,最佳氮源为豆粕,最佳无机盐离子为氯化钠。通过正交实验确定了该培养基的最佳配比为：玉米粉5g／L、豆粕15g／L、氯化钠10g／L。在确定适合该菌株的培养基组分基础上,对其培养条件进行优化,结果表明：初始pH值为6．0,培养时间为48h,转速为180r／min时为该菌株的最佳培养条件。 相似文献
8.
通过单因子试验和多因子正交试验,优化筛选了适于绣球菌摇瓶培养条件。结果表明,适于产菌丝体的摇瓶条件为:培养温度28℃,培养基起始pH4.5,接种量8%,摇瓶转速100r/min;摇瓶培养适于产菌丝体的最适碳氮源及其浓度分别为:可溶性淀粉2.5%,蛋白胨0.15%。适于产胞外多糖的摇瓶条件为:培养温度29℃,培养基起始pH5.5,接种量8%,摇瓶转速100r/min;摇瓶培养最适碳氮源及其浓度分别为:可溶性淀粉2.5%,蛋白胨0.25%。 相似文献
9.
为了获得高产纤维素酶菌株,有效地开发和利用纤维素资源.本研究通过对野外采集的大型真菌进行分离纯化,获得了16个菌株.利用CMC固体培养、刚果红染色,测量水解圈与菌落直径的比值(H/C值),对获得的菌株进行初筛;通过液体发酵培养,测定其上清液中的滤纸酶活力(FPA),对菌株进行复筛,最终获得了纤维素酶活性较高的菌株01.以稻草和羧甲基纤维素为碳源,研究了培养温度、pH值、培养时间对真菌菌株01产纤维素酶的影响.结果表明,该菌株产纤维素酶的最适培养温度为27℃,pH值为5.0,培养时间为6 d,菌株01的滤纸酶活性达到580.0 IU/mL.因此,真菌01可作为纤维素酶研究和饲料加工等生产的备选菌株. 相似文献
10.
研究了羊肚菌深层发酵培养基中玉米粉和黄豆粉配比和发酵条件,确定了羊肚菌深层发酵最佳配比的培养基以及最佳的发酵温度、起始pH和摇床转速.通过单因素确定培养基中玉米粉和黄豆粉的最佳配比,在单因素试验的基础上采用三因素三水平的响应面分析法确定羊肚菌液体发酵的培养条件.结果以羊肚菌菌丝体生物量和胞外多糖浓度为响应面和等高线,在分析各个因素的显著性和交互作用后,得出羊肚菌液体发酵的最佳温度25.33℃、起始pH 6.13、摇床转速154.33r/min.在最佳发酵条件下,发酵144h,羊肚菌的菌丝体生物量和胞外多糖浓度达到最高,分别为7.78g/L和130.97mg/L. 相似文献
11.
邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
12.
13.
14.
《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
15.
Rachel Zupek 《海外英语》2007,(11):40-41
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了 相似文献
16.
YANGShiguo 《重庆大学学报(英文版)》2004,3(1):86-88
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex. 相似文献
17.
《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
18.
Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
19.
20.
GUO Bao-feng Xiao Da-wei 《重庆大学学报(英文版)》2005,4(3):129-133
Using virtual reality for interactive design gives a designer an intuitive vision of a design and allows the designer to achieve a viable, optimal solution in a timely manner. The article discusses the process of making the Virtual Reality System of the Humble Administrator＇s Garden. Translating building data to the Virtual Reality Modeling Language （VRML） is by far unsatisfactory. This creates a challenge for computer designers to do optimization to meet requirements. Five different approaches to optimize models have been presented in this paper. The other methods are to optimize VRML and to reduce the file size. This is done by keeping polygon counts to a minimum and by applying such techniques as object culling and level-ofdetail switching. 相似文献