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1

Preparation, properties and suitability of thermostable enzymes

100%
Synowiecki J.
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|
issue 3
98-105
EN
Some enzymes from extreme thermophiles and hiperthermophiles have half-lives up to 13h at ,temperatures above 100?C. They are suitable for starch and whey processing, oil mining, PCR techni and oligosaccharides synthesis. The differences in structure and function between these very stable and the prevailing less stable enzyme forms are relatively small and are comparable with those differences found among enzymes of similar stability. The relationship of both conformational stability and enzymatic activity with protein flexibility suggests that stability at temperatures far above those which are optimum for the growth of microorganism is rather unlikely.
2

Characterization of bacteria of the genus Thermus and their biotechnological importance

64%
Sinkiewicz I., Synowiecki J.
Biotechnologia
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2009
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issue 3
148-162
EN
Gram-negative, aerobic bacteria of the genus Thermus which have been isolated from many natural and artificial, thermal environments are used as a source of thermostable restriction nucleases and DNA polymerase, as well as can be exploited for the production of many other enzymes with a great industrial importance. The strains belonging to the genus Thermus utilize carbohydrates, amino acids, carboxylic acids and peptides and their optimal growth temperatures ranged from 55 to 85oC. This review is focused on the adaptation of Thermus strains to thermostability and on characterisation and possible application of their enzymes.
3

Application of the cells of Escherichia coli transformant containing gene encoding thermostable beta-galactosidase from Pyrococcus woesei for the production of galactosylfructose

64%
Grubiak K., Synowiecki J.
|
EN
The gene encoding thermostable beta-galactosidase from Pyrococcus woesei was cloned and expressed in Escherichia coli cells. Furthermore, the obtained recombinant strain was used without additional cell permeabilization as a catalyst for the synthesis of galactosylfructose. The optimum pH and temperature for galactosylfructose production by recombinant cells were 5,4 and 80C, respectively. The highest process productivity (7,6 g/lh) was attained at the cells' concentration of 40 mg/ml of the reaction media, using a substrate containing 10% of lactose and 20% fructose. The transgalactosylation activity during the repeated bath processes was almost unchanged after sixfold application of the cells.
4

Characteristics and suitability of amaranth components in food biotechnology

64%
Januszewska-Jozwiak K., Synowiecki J.
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EN
Nutritional value of amaranth seed is mainly caused by lipids with a good ratio between saturated and unsaturated fatty acids and high protein content with the essential amino acids composition better than that in FAO/WHO standard. Furthermore, the lack of gluten fraction makse the amaranth flour suitable for production of the dietetic food used during celiakia healing. Fractionation of amaranth meal into starch, lipids and protein components leads to the products useful in food, cosmetics and pharmaceutical industries. The advantageous property of amaranth starch is small granule size which brings about its suitability, e.g., for production of food thickeners, dusting powders for cosmetics as well as component of nonallergenic aerosols and biodegradable plastics. Usefulness of this starch is also due to low amylose content. Amaranth oil has been reported to contain relatively large amount of squalene which is used as an important ingredient in skin cosmetics and penetrants and can reduce serum cholesterol.
5

Immobilization of recombinant beta-galactosidase in reactions catalysed by transglutaminase

64%
Wolosowska S., Synowiecki J.
|
EN
Thermostable beta-galactosidase from Escherichia coli transformant containing the enzyme gene from Pyrococcus woesei was immobilized at pH 5.5 on silica gel by crosslinking with transglutaminase. The obtained preparations had a specific activity of 11.573 U/g of support at 70C using oNPG as a substrate. The optimum pH and temperature for immobilized beta-galactosidase activity were 5.5 and 95C. The immobilized enzyme is stable at the temperatures close to the optimal value and the residual activity for oNPG hydrolysis of the preparations incubated 1 h in 0.1 M phosphate citrate buffer (pH 5.5) at 100C was about 70% of the initial value.
6

Beta-galactosidase activity of proteins extracted from Sulfolobus shibatae

64%
Wolosowska S., Synowiecki J.
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issue 2
268-279
EN
The cytoplasmic -beta galactosidase/beta-glucosidase from hyperthermophilic archaeon Sulfolobus shibatae has been characterized with regard to its use in lactose hydrolysis. Cell extract was purified 16-fold to a specific activity 29.5 U/mg using ammonium sulfate precipitation, ion-exchange chromatography, and gel filtration. Isolated enzyme exhibited optimum activity at pH 5.5 and 98C and had a half-life of 7 h in acetate buffer (pH 5.5) at 90C. Cu2+, Hg2+ and Zn2+ strongly inhibited the enzyme, whereas catalytic properties of other investigated cations were barely influenced. Glucose and galactose were predominantly produced from lactose. However, at the substrate concentration of 0.15, M small amount of lactose was converted into transgalactosylation products.
7

Production and selected applications of immobilized enzymes

64%
Synowiecki J., Wolosowska S.
Biotechnologia
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2007
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issue 2
7-26
EN
The presented data explain why application of immobilized enzyme systems is advantageous in many modern industrial technologies. Also, this reviev article contains information concerning the main methods developed for enzyme immobilization, as well as characteristic, suitability and properties of different carriers used for these purposes. Furthermore, the influence of immobilization process on changes of enzyme activity, selectivity, stability, conditions of catalysed reaction and other properties important in practical applications are described. Emphasis is placed on the choice of immobilized enzyme system adequate for the designed technology.
8

Suitability of Thermus ruber as a source of trehalose synthase

64%
Sinkiewicz I., Synowiecki J.
Biotechnologia
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2008
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issue 1
168-176
EN
Thermus ruber is a producer of trehalose synthase, which catalyses the conversion of maltose into trehalose by intramolecular transglucosylation. The specific activity of cell-free extract of Thermus ruber cultivated on a media without saccharides was 0.016-0.028 U/mg protein and it increased up to 0.086 U/mg in presence of 0.5% maltose in the culture broth. The maximum degree of maltose conversion of about 90% was achieved at 10% substrate concentration. The trehalose synthase does not catalyse formation of trehalose from maltotetraose, maltohexaose and other oligosaccharides. The optimal temperature for enzyme activity was 65C. A maximum activity of the maltose transglucosylation was performed at pH 6.5. The highest yield of trehalose synthase was attained during cultivation of bacteria at 55C for 48 h on media composed of 0.5% peptone, 0.1% yeast extract and 0.5% maltose or starch.
9

Some factors affecting the unique thermotolerance of hyperthermophiles

64%
Grzybowska B., Synowiecki J.
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|
issue 2
192-205
EN
The unique thermotolerance of hyperthermophiles, suitable as valuable sources of thermostable enzymes, is a result of various minor changes which led to the restriction of protein flexibility and modifications of nucleic acids and membrane lipids. Furthermore, all hyperthermophiles produce a number of heat shock proteins and thermoprotectants. Thermal resistance of these microorganisms is also enhanced by rapid resynthesis of thermolabile compounds and by elimination of such intermediates from cell metabolism.
10

Suitability of thermostable enzymes for improvment of starch processing

64%
Synowiecki J., Grzybowska B.
Biotechnologia
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2001
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issue 2
26-35
EN
Commercial processing of starch to mono-and oligosaccharides depends on the availability and properties of the applied enzymes such as -amylase, glucoamylase, -glucosidase and xylose isomerase. Each of these enzymes has a different pH and temperature optimum for use. Therefore starch processing is carried out in the stages of liquefaction, saccharification, and isomerisation. This article discusses the application of thermostable enzymes leading to higher quality products and lower production costs caused by the simplification of the processing.
11

Thermophiles as a source of alpha-glucosidases suitable for production of glucose syrups

64%
Synowiecki J., Zdzieblo A.
Biotechnologia
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2002
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issue 2
165-174
EN
Alpha-glucosidases release terminal, 1,4- and to lesser extend, 1,6- linked -glucose residues of disaccharides, oligosaccharides, and aryl-glucosides. Among these, novel thermostable enzymes from hyperthermophiles and moderate termophiles have been investigated. The aim of this article is to demonstrate different sources of thermostable alpha-glucosidases, as well as properties and suitability of these enzymes for production of glucose at 90-100C, e.g., during one step process initiated by starch liquefaction using commercial alpha-amylase (Termamyl).
12

Evaluation of Thermus ruber as a source of thermostable (-glucosidase useful for production of glucose syrups

64%
Sinkiewicz I., Synowiecki J.
Biotechnologia
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2009
|
issue 2
134-146
EN
Thermus ruber produces (-glucosidase detected in the crude extract of cell proteins. This enzyme exhibits optimum actiivity at 65(C and pH 6,0. The enzyme was stable within a range of pH 5.5 to 8.0 and in 65(C for 60 min. The rate of p-nitrophenol-(-D-glucopyranoside cleavage was higher than that for maltose. With maltotetraose, maltopentaose and maltohexaose, the hydrolysis rate decreased with increasing the molecular weight of the substrate. Our data suggest that the starch converting process could be improved using (-glucosidase from Thermus ruber.
13

Suitability and properties of beta-galactosidases from different sources

64%
Synowiecki J., Maciunska J.
Biotechnologia
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2000
|
issue 1
117-123
EN
The article reviews the progress of investigations of b-galactosidases from microbial sources. These enzymes show great differences in optimal conditions of lactose hydrolysis and their utilisation create new possibilities to improve milk and milk by-products processing. Some beta-galactosidases from extreme thermophiles have significant activity above 100?C. Possible applications and interrelationship of both molecular structure and thermostability of these enzymes are also discussed.
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