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1

Saccharomyces cerevisiae in biotransformations

100%
Bialecka-Florjanczyk E., Majewska E.
Biotechnologia
|
2006
|
issue 3
113-133
EN
In the last decade, whole cells and enzymes have been used extensively in organic synthesis to obtain homochiral products in a variety of organic reactions. Baker's yeast, which has a large potential as a catalyst in organic chemistry, owing to ease of handling and broad substrate acceptability, has been widely used, mainly in the reduction of the carbonyl groups of prochiral ketones, producing alcohols with high enantiomeric purity. This review describes the most relevant recent papers not only on the reduction of carbonyl groups, but also on other aspects of utilizing baker's yeast.
2

Secondary metabolites from transformed root cultures

80%
Wysokinska H.
Biotechnologia
|
2000
|
issue 4
32-39
EN
Transformed roots in axenic culture would prove to be a good model for the study of the aspects of secondary metabolism. They are morphologically differentiated and have the advantage of high growth in the liquid standard media without growth regulators. Hairy root cultures can express root-specific pathways and have stable production of alkaloids, polyacetylenes, sesquiterpenes, naphthoquinones and other natural products. They can also convert xenobiotics into bioactive metabolites. Thus, new compounds not found in the parent plants could be obtained. Despite encouraging results, no commercial application of hairy root cultures for production of secondary metabolites have been developed, so far. A lot of further work is required to optimize bioreactor design for differentiated plant organ and to improve productivity of hairy roots.
3

Presence, biological role and biotransformation of limonene

80%
Trytek M., Kowalski P., Fiedurek J.
Biotechnologia
|
2003
|
issue 2
206-217
EN
Monoterpenes, widely distributed in nature, constitute suitable precursor substrates for potential production of valuable natural flavour and fragrance compounds. Among various monoterpenes, limonene is a cheap and readily available starting material, utilized for e.g. biotransformation into more valuable compounds like carvone and alpha-terpineol. This rewiev presents properties, application, and possibilities, as well as trials of biotechnological conversion of limonene using some microorganisms.
4

Biotransformation by plant cell cultures. Part II. Process conditions

80%
Chmiel A., Wysokinska H.
Biotechnologia
|
1995
|
issue 1
131-147
EN
Biological and biochemical conditions of biotransformation processes ,applications of cell suspension, immobilised cells and enzyme preparations are discussed.The nature and form of biocatalysts determine the technical parameters of the process.Bioreactor systems for plant cell biotechnology are presented.
5

Biotransformation by plant cell cultures. Part I. Reactions

80%
Wysokinska H., Chmiel A.
Biotechnologia
|
1995
|
issue 1
114-130
EN
Plant enzymes are able to catalyse regio- and stereospecific reactions and can be applied to the production of pharmaceutically important compounds.This paper summarizes the results of such biotransformations in freely suspended cells.The factors affecting bioconversion capabilities of cells are also discussed.Special attention is paid to permeabilization and the problems of poorly water-soluble precursors.
6

The comparison of praziquantel biotransformation in silico and in vitro

80%
Godawska A., Pekala E., Kiec-Kononowicz K.
Biotechnologia
|
2005
|
issue 1
215-222
EN
Praziquantel (PZQ) is a drug which is used by choice to schistosomiasis treatment. Currently, it is used in malaria treatment. PZQ undergoes extensive metabolism in human body, mainly in liver, by two cytochrome P-450 isoenzymes 2B1 and 3A. As a result of these biotransformations, numerous mono- and dihydroxylated derivates in B, C and D rings are formed. Only one metabolite has been identified and described, it is 4-hydroxypraziquantel (4-OH-PZQ). So for, the metabolites out of PZQ biotransformation were obtained under the influence of Cunnighamelle echinulata and Beauveria bassiana. There were the derivatives in position C7 and in D-ring (position is unknown). In our research, we would like to create a new model of PZQ biotransformation in vitro. For such purpose, Saccharomyces cerevisiae were used. The results of PZQ biotransformation in vitro under the influence of Saccharomyces cerevisiae were compared with computer simulation of PZQ metabolism performed by the use of Metabol Expert program.
7

Microorganisms in stereoselective organic synthesis

70%
Niemiec A., Szeja S. W., Szeja W.
Biotechnologia
|
2001
|
issue 3
104-123
EN
This paper deals with the use of microorganisms for the synthesis of homochiral compounds. The influence of various factors on the efficiency of biotransformation employing whole cells is discussed. The author?s attention was focused on stereochemistry of reaction since the knowledge of its rules allows to control the stereoselectivity and productivity of biotransformation. Some interesting examples of best documented bioreduction and biooxidation reactions were selected and are reported in this article.
8

Monoterpenes ? old compounds, new applications, and biotechnological methods of their production

70%
Trytek M., Paduch R., Fiedurek J., Kandefer-Szerszen M.
Biotechnologia
|
2007
|
issue 1
135-155
EN
Monoterpenes, are the largest class of plant secondary metabolites. The review discusses some of their key roles in chemical ecology. Several applications of monoterpenes in flavour and fragrance industry, bioremediation, in prevention and therapy of several inflammatory infection, potential disease-preventive phytochemicals, especially for cancer development, are presented. This review also aims at a potential offered by biocatalysis for the synthesis of valuable natural monoterpenes, highlighting relevant biotransformation of suitable precursors (like pinene, limonene, myrcene) using microorganism and porphyrins. The industrial processes based on biotechnological methods are also discussed in terms of their advantages over classical chemical synthesis and extraction from natural sources.
9

Application of pig liver esterase in organic synthesis

70%
Mroczkiewicz M., Fryszkowska A., Ostaszewski R.
Biotechnologia
|
2005
|
issue 2
32-47
EN
Pig liver esterase (PLE) is widely used as a biocatalyst in organic synthesis. The model of PLE catalytic center is discussed. Simple experimental procedure providing gram quantity of this enzyme is introduced. General aspects of PLE reactivity and selectivity are presented. The most representative chemical reactions catalyzed by PLE are shown on selected examples.
10

Biotransformation of L-arabinose to arabitol by yeasts from genera Pichia and Candida

70%
Kordowska-Wiater M., Targonski Z., Jarosz A.
Biotechnologia
|
2008
|
issue 1
177-188
EN
Biotransformation of L-arabinose to arabitol by selected yeasts was described. P. stipitis CCY 39501, P. guilliermondii DSM 70052, C. shehatae 3504, C. shehatae ATCC 22984, C. pseudotropicalis IPF 65, C. parapsilosis DSM 70125 were investigated to produce L-arabitol. C. parapsilosis DSM 70125 was the best producer of arabitol that was detected in concentrations 10-14 gdm-3 in the medium. The highest yield (0,78 gg-1) and productivity (0,036 g(gxh)-1) were also obtained for this strain. The other quite good producers of arabitol were P. guilliermondii DSM 70052 and C. shehatae ATCC 22984 that produced poliol with yields 0,43 gg-1 and 0,50 gg-1, respectively, in optimal conditions. Rotation conditions of shaker on the level 150 rpm and temperature of incubation 28C were selected to be optimal for biotransformation by all yeasts.
11

Porphyrins and phthalocyanines. Part. II. Porphyrins as biomimetic catalysts in organic compounds transformation

61%
Trytek M., Fiedurek J., Polska K., Makarska M., Radzki S.
Biotechnologia
|
2005
|
issue 4
128-141
EN
The interest in the use of metal porphyrins in biomimetic catalysis has been constantly increasing during the last twenty years, as the enzymology studies were showing the role of this complexes as prosthetic groups of cytochromes P-450, peroxidases and catalases. In particular, a number of research groups have focused their interest on the ability of metal porphyrins to catalyze redox processes on organic compounds under mild conditions, both for converting these compounds into more usuful products and for purifying industrial effluents. The aim of this review is to highlight the efforts of researchers in utilising metalloporphyrins for economically attractive processes. Interesting reactions are allylic hydroxylations of cheap and readily available precursor monoterpenes (like limonene, pinene) for potential production of valuable natural flavour and fragrance compounds, selective oxidation of alkyl chains of the alkanes, regioselective oxidation of cyclic hydrocarbons (eg. cycloheksan), steroids, as well as reduction of the halogenated alkanes.
12

Mercury removal from aqueous solutions by biotransformation

61%
Ledakowicz S., Deckwer W.-D.
Biotechnologia
|
1993
|
issue 3
99-107
EN
Experimental investigations of of mercury Hg(O) in by were carried out in two types of lab : in fixed and fluized bed. An isolated and identified natural strain of Aeromoans hydrophila was immobilized on the surfaces of porous carriers and employed in mercury removal from liquid phase in the fixed bed reactor. For mercury biotransformation in the fluidized bed a geneticaly modified strain of Pseudomonas putida KT2442:: mer 73 entraped in PVA gel beads was used. The investigations reveal that mercury biotransformation is a fast process controlled by diffusion. The most promising way of mercury removal from waste-water is employment of fluidized bed of immobilized bacteria, because of continuous mercury volatilization and possible recovery of this metal.
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