Purification and characterization of the heat-labile α-amylase secreted by the psychrophilic bacterium TAC 240B

1999 ◽  
Vol 45 (6) ◽  
pp. 452-457 ◽  
Author(s):  
Jean-Pierre Chessa ◽  
Georges Feller ◽  
Charles Gerday
Keyword(s):  
Molecular Structure ◽  
High Temperature ◽  
Low Temperature ◽  
Sea Water ◽  
Maximal Activity ◽  
Psychrophilic Bacterium ◽  
Purification And Characterization ◽  
Allosteric Effector ◽  
Psychrophilic Enzyme

A total of 59 bacteria samples from Antarctic sea water were collected and screened for their ability to produce α-amylase. The highest activity was recorded from an isolate identified as an Alteromonas species. The purified α-amylase shows a molecular mass of about 50 000 Da and a pI of 5.2. The enzyme is stable from pH 7.5 to 9 and has a maximal activity at pH 7.5. Compared with other α-amylases from mesophiles and thermophiles, the "cold enzyme" displays a higher activity at low temperature and a lower stability at high temperature. The psychrophilic α-amylase requires both Cl-and Ca2+for its amylolytic activity. Br-is also quite effecient as an allosteric effector. The comparison of the amino acid composition with those of other α-amylases from various organisms shows that the cold α-amylase has the lowest content in Arg and Pro residues. This could be involved in the principle used by the psychrophilic enzyme to adapt its molecular structure to the low temperature of the environment. Key words: α-amylase, psychrophilic microorganisms, Antarctic.

scholarly journals Partial purification and characterization of xylanase from Bacillus cereus X3

2014 ◽  
Vol 11 (2) ◽  
pp. 1056-1061
Author(s):  
Baghdad Science Journal
Keyword(s):  
Bacillus Cereus ◽  
Maximal Activity ◽  
Partial Purification ◽  
Purification And Characterization ◽  
Xylanase Production ◽  
Optimum Activity ◽  
Biology Department ◽  
Characterization Study ◽  
Quantitative Screening

Three strain of Bacillus cereus were obtained from soil sours Laboratories of Biology Department/ College of Science/ University of Baghdad. The bacteria secreted extracellular xylanase in liquid cultur the test ability of xylanase production from these isolates was studied semi quantitative and quantitative screening appeared that Bacillus cereus X3 was the highest xylanase producer. The enzyme was partial purification 191 fold from cultur by reached step by 4 U/mg proteins by ammonium sulfat precipitation 80%, Ion exchang DEAE-cellulos chromatography Characterization study of the partial purifation enzyme revealed that the enzyme had a optimum activity pH8 and activity was stable in the pH rang (8-10) for 30min. maximal activity was attained at 50C

Synthesis and Characterization of Aerogel-derived Cation-substituted Hexaaluminates

1996 ◽  
Vol 457 ◽  
Author(s):  
Lin-chiuan Yan ◽  
Levi T. Thompson
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Catalytic Combustion ◽  
High Surface ◽  
High Surface Area ◽  
Synthesis And Characterization ◽  
New Methods ◽  
Surface Areas ◽  
Different Characteristics

ABSTRACTNew methods have been developed for the synthesis of high surface area cation-substituted hexaaluminates. These materials were prepared by calcining high temperature (ethanol extraction) or low temperature (CO2 extraction) aerogels at temperatures up to 1600°C. Cation-substituted hexaaluminates have emerged as promising catalysts for use in high temperature catalytic combustion. In comparing unsubstituted and cation-substituted hexaaluminates, we found that the phase transformations were much cleaner for the cation-substituted materials. BaCO3 and BaAl2O4 were intermediates during transformation of the unsubstituted materials, while the cation-substituted materials transformed directly from an amorphous phase to crystalline hexaaluminate. Moreover, the presence of substitution cations caused the transformation to occur at lower temperatures. Mn seems to be a better substitution cation than Co since the Mn-substituted materials exhibited higher surface areas and better heat resistances than the Co-substituted materials. The low temperature aerogel-derived materials possessed quite different characteristics from the high temperature aerogel-derived materials. For example, phase transformation pathways were different.

scholarly journals Purification and characterization of two initiation factors required for maximal activity of a highly fractionated globin mRNA translation system.

1976 ◽  
Vol 73 (8) ◽  
pp. 2584-2588 ◽  
Author(s):  
B. Safer ◽  
S. L. Adams ◽  
W. M. Kemper ◽  
K. W. Berry ◽  
M. Lloyd ◽  
...  
Keyword(s):  
Mrna Translation ◽  
Maximal Activity ◽  
Translation System ◽  
Purification And Characterization ◽  
Globin Mrna ◽  
Initiation Factors

scholarly journals Purification and Characterization of Cold-Adapted Metalloprotease from Deep Sea Water Lactic Acid Bacteria Enterococcus Faecalis TN-9

2009 ◽  
Vol 1 (2) ◽  
Author(s):  
Qingzhu Yuan ◽  
Atsushi Hayashi ◽  
Yoshihisa Kitamura ◽  
Takashi Shimada ◽  
Ren Na ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Enterococcus Faecalis ◽  
Deep Sea ◽  
Sea Water ◽  
Purification And Characterization ◽  
Cold Adapted ◽  
Deep Sea Water

Purification and Characterization of a Cold-active Iron Superoxide Dismutase from a Psychrophilic Bacterium, Marinomonas sp. NJ522

2006 ◽  
Vol 28 (2) ◽  
pp. 85-88 ◽  
Author(s):  
Zhou Zheng ◽  
Ying-Hui Jiang ◽  
Jin-Lai Miao ◽  
Quan-Fu Wang ◽  
Bo-Tao Zhang ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Psychrophilic Bacterium ◽  
Purification And Characterization ◽  
Iron Superoxide Dismutase ◽  
Active Iron ◽  
Cold Active

Purification and characterization of a low-temperature ammonia monooxygenase from heterotrophic nitrifierAcinetobactersp. Y16

2013 ◽  
Vol 53 (1) ◽  
pp. 257-262 ◽  
Author(s):  
Shumei Zhang ◽  
Weiguang Li ◽  
Duoying Zhang ◽  
Xiaofei Huang ◽  
Wen Qin ◽  
...  
Keyword(s):  
Low Temperature ◽  
Ammonia Monooxygenase ◽  
Purification And Characterization

Purification and characterization of a thermostable α-glucosidase from aBacillus subtilis high-temperature growth transformant

1991 ◽  
Vol 22 (5) ◽  
pp. 273-278 ◽  
Author(s):  
Bradley M. Krohn ◽  
James A. Lindsay
Keyword(s):  
High Temperature ◽  
Purification And Characterization ◽  
Temperature Growth

Characterization of the melting behavior of high-temperature and low-temperature ashes

2015 ◽  
Vol 134 ◽  
pp. 441-448 ◽  
Author(s):  
Jie Xu ◽  
Feng Zhao ◽  
Qinghua Guo ◽  
Guangsuo Yu ◽  
Xia Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Melting Behavior
Sign in / Sign up

Export Citation Format

Share Document