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New applications of biocatalysts
WRIGHT AD, SAMPSON B, NEUFFER MG, MrcHALczux L, SLOVINJP, COHEN JD: Indole-3-acetic Acid Biosynthesis in the Mutant Make Orange Pericarp, a Tryptophan Auxotroph. Science 1991, 254:99f&lOO0. Up until now, tryptophan has been considered to be the precursor of IAA in plants. This article shows that this is not the case in maize. Consequently, it is a seminal work in phytohormone research.
HJ, HAyFoRD MB, KRETZMER JSA, BARRYGF, USHORE GM: Control of Ethylene Synthesis by Expression of a Bacterial Enzyme in Transgenic Tomato Plants. Plant Cell 1991, 3:1187-1193. Expression of an ACC deaminase in transgenic plants curtailed ethylene production at a level only 10% of that synthesized in normal plants. This approach to the reduction in ethylene production should function in any plant species. KLEE
High cell density and high productivity microbial fermentation: methods, applications, and products by Gary L. Kleman and William R. Strohl Production of 2,3Bioreactor with Cell Re-
ZENG AP, BIEBL H, DECKWER WD:
Butanediol in a Membrane
cycle. Appl Microbiol Biotechol
1991, 34453-468.
The effects of oxygen supply, cell residence time, dilution rate and pH upon the production of 2,3-butanediol by E?zterobczctq uerogenes were studied in a cell recycle system. The productivity obtained in this fermentor was three times greater than in normal continuous fermentations. Acetate was the major inhibitory compound of production; pH control was found to improve productivity at high cell densities, including fed-batch fermentations. Wmso~ DL, HARRISON RG: Predicting the Solubility of Recombinant Proteins in Eschericbia coli. Biotecb nology 1991, 9:443-448. Using a database of 81 proteins, the inclusion body formation of proteins produced by E. coli growing at 37°C was studied. Of the six parameters examined, charge average and turn-forming residue fraction were the two factors that were found to have the highest correlation for determining the solubility of the protein A method was presented for calculating the probability of inclusion body formation from the amino acid sequence of a protein. Buc~~orz RG, GIEESON MAG: Yeast Systems for the Commercial Production of Heterologous Proteins. Biotecbndo~ 1991, 9:1067-1072. The authors compared the suitability of various yeast strains as hosts for recombinant DNA They make a strong case for the use of yeasts other than S. cf?revt&e as recombinant hosts.
274
New applications Saul L. Neidleman
of biocatalysts
by
LEE Y-D, Kul H-S: Enhancement of Enzymatic Production of Cyclodextrins by Organic Solvents. Enzyme Microb Tecbnol 1331, 13:499-503. Describes the enhancement of the enzymatic synthesis of cyclodextrins by 100 % in the presence of 10 % ethanol. One strength of the paper is the study of a variety of organic solvents clearly demonstrating the impact of solvent structure and chemically properties.
MAL4THI s, CHAKRAB om R: Production of Alkaline Protease by a New Aspetgillus flaws Isolate Under Solid-substrate Fermentation Conditions for Use as a Depilation Agent. Appl Environ Mb&o1 1991, 57~712-716. Illustrates some of the advantages of solid-state fermentations compared with submerged culture fermentations for the production of useful proteases. The use of solid state fermentation rather than a submerged culture process is a reminder that the method of enzyme production should be a major consideration when studying an enzyme for industrial use. MUIBRY WM, EATON RW: Isolation and Characterization of the N-Methylcarbamate Hydrolase from Pseudomonas Strain CRL-OK. Appl Environ Microbial 1991, 57~36793682. This paper describes the isolation and characterization of an enzyme to degrade amino-methylcarbamate pesticides. It clearly illustrates the potential of biological system for the bioremediation of specific pesticide pollutants.
large scale plant cell culture: methods, applications and products by Alan H. Scragg GH, TEN HOOPEN Dielectric Spectroscopy nient Tool for the Study Plant Cells in Suspension 1945-158. MARKS
HJG, MEIJER JJ, VINKE KL as a Novel and Conveof the Shear Sensitivity of Culture. J Biotedmol 1991,
Permittivity measured at known radio frequencies is a measure of charge separation across a membrane. Any loss would indicate a loss of membrane integrity and hence viability. Although cells may lose their ability to grow and divide but still retain membrane integrity, the method conhrms previous observations of the effect of shear stress on plant cells, and also has the advantage of being rapid. Of the few cell lines tested, three were more shear tolerant than generally believed. This has considerable implications for the use of stirred-tank bioreactors for the growth of plant cells.
@ 1992 Current Biology
HJ, HAyFoRD MB, KRETZMER JSA, BARRYGF, USHORE GM: Control of Ethylene Synthesis by Expression of a Bacterial Enzyme in Transgenic Tomato Plants. Plant Cell 1991, 3:1187-1193. Expression of an ACC deaminase in transgenic plants curtailed ethylene production at a level only 10% of that synthesized in normal plants. This approach to the reduction in ethylene production should function in any plant species. KLEE
High cell density and high productivity microbial fermentation: methods, applications, and products by Gary L. Kleman and William R. Strohl Production of 2,3Bioreactor with Cell Re-
ZENG AP, BIEBL H, DECKWER WD:
Butanediol in a Membrane
cycle. Appl Microbiol Biotechol
1991, 34453-468.
The effects of oxygen supply, cell residence time, dilution rate and pH upon the production of 2,3-butanediol by E?zterobczctq uerogenes were studied in a cell recycle system. The productivity obtained in this fermentor was three times greater than in normal continuous fermentations. Acetate was the major inhibitory compound of production; pH control was found to improve productivity at high cell densities, including fed-batch fermentations. Wmso~ DL, HARRISON RG: Predicting the Solubility of Recombinant Proteins in Eschericbia coli. Biotecb nology 1991, 9:443-448. Using a database of 81 proteins, the inclusion body formation of proteins produced by E. coli growing at 37°C was studied. Of the six parameters examined, charge average and turn-forming residue fraction were the two factors that were found to have the highest correlation for determining the solubility of the protein A method was presented for calculating the probability of inclusion body formation from the amino acid sequence of a protein. Buc~~orz RG, GIEESON MAG: Yeast Systems for the Commercial Production of Heterologous Proteins. Biotecbndo~ 1991, 9:1067-1072. The authors compared the suitability of various yeast strains as hosts for recombinant DNA They make a strong case for the use of yeasts other than S. cf?revt&e as recombinant hosts.
274
New applications Saul L. Neidleman
of biocatalysts
by
LEE Y-D, Kul H-S: Enhancement of Enzymatic Production of Cyclodextrins by Organic Solvents. Enzyme Microb Tecbnol 1331, 13:499-503. Describes the enhancement of the enzymatic synthesis of cyclodextrins by 100 % in the presence of 10 % ethanol. One strength of the paper is the study of a variety of organic solvents clearly demonstrating the impact of solvent structure and chemically properties.
MAL4THI s, CHAKRAB om R: Production of Alkaline Protease by a New Aspetgillus flaws Isolate Under Solid-substrate Fermentation Conditions for Use as a Depilation Agent. Appl Environ Mb&o1 1991, 57~712-716. Illustrates some of the advantages of solid-state fermentations compared with submerged culture fermentations for the production of useful proteases. The use of solid state fermentation rather than a submerged culture process is a reminder that the method of enzyme production should be a major consideration when studying an enzyme for industrial use. MUIBRY WM, EATON RW: Isolation and Characterization of the N-Methylcarbamate Hydrolase from Pseudomonas Strain CRL-OK. Appl Environ Microbial 1991, 57~36793682. This paper describes the isolation and characterization of an enzyme to degrade amino-methylcarbamate pesticides. It clearly illustrates the potential of biological system for the bioremediation of specific pesticide pollutants.
large scale plant cell culture: methods, applications and products by Alan H. Scragg GH, TEN HOOPEN Dielectric Spectroscopy nient Tool for the Study Plant Cells in Suspension 1945-158. MARKS
HJG, MEIJER JJ, VINKE KL as a Novel and Conveof the Shear Sensitivity of Culture. J Biotedmol 1991,
Permittivity measured at known radio frequencies is a measure of charge separation across a membrane. Any loss would indicate a loss of membrane integrity and hence viability. Although cells may lose their ability to grow and divide but still retain membrane integrity, the method conhrms previous observations of the effect of shear stress on plant cells, and also has the advantage of being rapid. Of the few cell lines tested, three were more shear tolerant than generally believed. This has considerable implications for the use of stirred-tank bioreactors for the growth of plant cells.
@ 1992 Current Biology