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1.
研究了以Na_2SO_4为主要盐析剂提取碱性蛋白酶的工艺,分别就Na_2SO_4加量、pH和温度3个因素进行了试验,得出Na_2SO_4最佳用量为25%、最佳pH为8.5和最适温度30℃.其中Na_2SO_4加量是影响盐析的主要因素。本文还以有机溶剂丙酮对酶的提取作了初步研究,可考虑用于生产食品级碱性蛋白酶。  相似文献   

2.
提高碱性蛋白酶生产效率的工艺条件研究   总被引:1,自引:0,他引:1  
裘娟萍  钟卫鸿 《科技通报》1996,12(4):207-210
在地衣芽孢杆菌生长到对数期后期,添加0.01%表面活性剂TX-10碱性蛋白酶产量可提高27.8%,当发酵液pH接近7.2左右时酶活接近峰值。此时应及时停止供氧,终止发酵;若继续通风培养4h时可使酶活平均下降38%左右。  相似文献   

3.
高效液相色谱法测定饲料中色氨酸含量   总被引:3,自引:0,他引:3  
李家胜  陈忠明 《科技通报》1999,15(3):219-222
样品用淀粉-氢氧化钡溶液110℃封管水解24h水解物用4mol/LHCl溶液调节pH至5~6以含15%甲醇的0.02mol/LNaAc缓冲溶液(pH=4.5)为流动相,经高效液相色谱C18柱分离,UV280nm检测,测定了饲料样品中色氨酸含量,方法简便,重现性好,回收率在97.7%~104.1%之间。  相似文献   

4.
孙性善  郑根香 《科技通报》1994,10(2):120-123
报道了Iodogen法碘化标记单克隆抗体(单抗)的最佳条件和对标记单抗免疫活性影响的实验结果,结果表明,当Iodogen:McAb=1:4缓冲液pH=7.4,旋涡搅拌10min时,标记率、放化纯和峰值百分率均较高,标记单抗的免疫活性与标记前比较没有统计学差异(P>0.05)。 ̄131I-HCM83和 ̄125I-VCMC与阳性对照结合率为38.2%和30.1%,P/N为9.1和30.1。此通用技术具有推广应用价值。  相似文献   

5.
碱性纤维素酶产生菌的筛选及其产酶条件   总被引:4,自引:0,他引:4  
宁静 《科技通报》2000,16(3):216-218
从土壤样品中筛选到一株产碱性纤维素酶的菌株SYH-1,产酶的最适碳源为麸皮,最适氮源为豆饼粉,摇瓶发酵最高酶活25u/mL,酶反应的最适温度为50℃,pH为9.6,主要作用底物为CMC,对滤纸,纤维素粉和结晶纤维素几乎作用。  相似文献   

6.
唐良华  夏黎明  苏敏 《科技通报》2006,22(5):622-627
利用均匀设计法对Bacillus sp.ZJU318产酶的最佳培养基进行了快速优化研究。结果表明,其最适产酶培养基为:3.28%黄豆粉,0.023%蔗糖,0.075%K2HPO4,配制时的pH为12(灭菌后pH为8~9);此外,其发酵的最佳条件为:发酵温度28℃,接种量20%,摇瓶装量20mL(250mL三角瓶)。在最适的发酵条件下,脂肪酶的发酵水平可达24.7U/mL。Bacillus sp.ZJU318脂肪酶作用的最适温度为45℃,40℃保温1h,活力几乎没有损失;但是,在50℃和60℃的条件下保温1h后,酶活降低得比较明显;酶作用的最适pH为9.0。在pH7~10,该脂肪酶较稳定,但是在酸性的环境中,酶的稳定性较低。  相似文献   

7.
黄健辉  徐俊良 《科技通报》1996,12(6):324-328
由控制饲料的pH值和缓冲液浓度来确定饲料的缓冲力,并配制不同水平的人工饲料饲育家蚕,检测三者间对饲料质量影响的主次。结果表明:饲料的缓冲力、pH值以及缓冲液度对家蚕的生长发育有显著影响,饲料缓冲液浓度和缓冲力的增加,饲料pH值的降低,都会引起蚕体重增量、相对生长率和净生长效率的降低,龄期经过的延长、消化后用于能量代谢的食物量的增加。在检验的pH值范围内(4.0 ̄5.5),饲料pH值对家蚕生长发育和  相似文献   

8.
由控制饲料的pH值和缓冲液浓度来确定饲料的缓冲力,并配制不同水平的人工饲料饲育家蚕,检测三者间对饲料质量影响的主次.结果表明:饲料的缓冲力、pH值以及缓冲液浓度对家蚕的生长发育有显著影响.饲料缓冲液浓度和缓冲力的增加,饲料pH值的降低,都会引起蚕体重增量、相对生长率和净生长效率的降低,龄期经过的延长、消化后用于能量代谢的食物量的增加.在检验的pH值范围内(4.0~5.5),饲料pH值对家蚕生长发育和适口性的影响要小于饲料缓冲力,而略大于缓冲液浓度.  相似文献   

9.
运用三元能量作用于马铃薯,其比对照组产量提高19.18%,结果个数增加18.30%,单薯重量减少0.54%,经统计分析,前两项达到显著水平第3项差异不显著,证明了三元能量可促使马铃薯增产。  相似文献   

10.
蔡梅芳  朱佩祯 《科技通报》1996,12(5):309-311
对56例消化性溃疡患者,平分两组分别用奥美拉唑及进口洛赛克治疗4周。结果:奥美后唑总有效率96%,洛赛克100%,两者差异无显著性;两组治疗前后快速尿素酶试验阳性率相比差异无显著性;治疗前与治疗后胃液pH值相比两组差异均有高度显著性。奥美拉唑费用低,有推广价值。  相似文献   

11.
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China's science enterprise by making S&T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party's Leading-member Group at CAS, which was held from 7 to 11 January in Beijing.  相似文献   

12.
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants."  相似文献   

13.
Aresearch project on the greenhouse cultivation of Swertia chirayita Buch Ham, a popular herbal drug used by the Tibetan people against liver and gallbladder diseases, recently passed the acceptance check by a panel of experts under the auspices of Qinghai Provincial S&T Bureau. The feat was accomplished by researchers from the Lanzhoubased CAS Northwest Institute of Plateau Biology.  相似文献   

14.
The research into the origins of domestic animals is of significance not only for understanding their development per se, but also for making clear the human society evolution. Although there are evidences to show that pigs were independently domesticated in a variety of places throughout the world, the detailed scenario of the origin and dispersal of domestic pigs in East Asia remains unclear.  相似文献   

15.
Among the galaxy of research and development organizations in northwest Beijing's Zhongguancun district, known as China's Silicon Valley, two are especially well-known to IT researchers: Microsoft Research Asia (MSRA), and, within a few blocks on the other side of the street, the CAS Institute of Automation (CASIA). While most people in Chinese scientific organizations strive to move to a large foreign counterpart, Dr. Stan Z. Li (LI Ziqing) moves against the stream.  相似文献   

16.
Prof. SUN Changpu from the CAS Institute of Theoretical Physics and coworkers from University of Basel in Switzerland have worked out a way --at least in theory --to split a beam of molecules according to their chirality. The technique involves passing the molecules through three different laser beams and is similar to the famous Stern-Gerlach effect, whereby a beam of atoms passing through a magnetic field is split in two according to the atoms' spin states (Phys. Rev. Lett. 99 130403).  相似文献   

17.
<正>In February 2014,the 30th Chinese Antarctic inland expedition team reported that they have successfully conducted the seeing measurement at the Antarctic Taishan Station using a Differential Image Motion Monitor(DIMM)developed by the Nanjing Institute of Astronomical Optic and Technology(NIAOT),Chinese Academy of Sciences.In astronomy,seeing is a physical parameter that describes the irregular movement and blur of the star  相似文献   

18.
Amassive overhaul is coming to the Chinese Academy of Sciences (CAS). To straighten its "fragmented, inefficient research", the academy has decided to restructure its 104 institutes for better teamwork.  相似文献   

19.
<正>DNA demethylation in mammalian zygotes,a biochemical process through which the parental genomes let go the epigenetic marks from their"past lives"to obtain totipotency,has long fascinated biologists:how does it happen?A joint team at the CAS Shanghai Institutes for Biological Sciences tells a surprising story.  相似文献   

20.
China is one of the fastest growing economies worldwide. Are science and research also in the fast lane? We talked with LUO Yuan, scientist at the Institute of Coal Chemistry in Shanxi, and Axel Mosig, Professor at Ruhr University in Bochum, who has first-hand experience working and living in China.  相似文献   

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