Wyniki wyszukiwania - Biblioteka Nauki

1

Pyridoxal phosphate dependent enzymes ? characteristics and application in biotechnology

100%

Wozniak M. , Koziolkiewicz M.

Biotechnologia

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2005

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nr 4

63-81

EN

Pyridoxal phosphate (PLP)-dependent enzymes catalyze broad range of reactions. They are involved in biotransformation of amino acids and their derivatives in bacteria, fungi, plants and animals. Recently, due to development of crystallographic technology, three-dimensional structures of some PLP-enzymes are being solved. A comparison of tertiary structure of these enzymes has shown that most of them can be divided into three classes of homologous proteins. This review contains short characteristics of PLP-dependent enzymes, regarding to their substrates and the reaction types catalyzed. Because of wide distribution and involvement in numerous important cellular processes, these enzymes are considered as candidates for drug targets. Better understanding of structures and functions of this important group of enzymes is essential for designing their inhibitors and for synthesis of improved protein-based catalysts.

2

Enzymatic reactions in supercritical CO2

100%

Malinowski J. J. , Jarzebski A. B.

Biotechnologia

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1999

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nr 1

238-246

EN

Applications of supercritical fluid technology in enzymatic biocatalysis is reviewed. The influence of the pressure, moisture level and entrainers on the performance of enzymatic reactions in supercritical CO2 are discussed.

3

Membrane reactor - new possibilities

80%

Noworyta A. , Bryjak J.

Biotechnologia

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1993

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nr 3

4-15

EN

The flow-sheet of for biotechnological application has been presented in the paper. The relevant topics that concern problems of microbial or as well as separation of reaction system onto the fractions with different residence time distributions have been overiewed. A set of conditions has been specified for membranes applied in the system. The following types of bioreactors have been characterized in detail i.e.:i) case of bioreactor for hydrolysis of penicillinum G and ii) case of microbial membrane bioreactor for culture and harvesting of biomass iii) microbial membrane bioreactor for alcohol fermentation.

4

Studies on enzyme activity in the petroleum contaminated soil, detoxification in a soil

80%

Malachowska-Jutsz A. , Mrozowska J. , Kozielska M. , Miksch K.

Biotechnologia

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1997

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nr 1

79-91

EN

In this paper the influence of selected oils which are aromatic hydrocarbons on microbial activity of a soil is discussed.Selected enzymes: amylases, proteases, dehydrogenases ans celulase Cx were tested.

5

Biotransformation by plant cell cultures. Part II. Process conditions

80%

Chmiel A. , Wysokinska H.

Biotechnologia

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1995

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nr 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.

6

Bioencapsulation of biologically active compounds In matrices obtained by sol-gel metod and its application

80%

Polska K. , Fiedurek J. , Radzki S.

Biotechnologia

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2007

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nr 1

77-95

EN

The encapsulation of biomolecules, e.g. enzymes, whole living cells or microorganisms in sol-gel derived monolithic silica, has been widely studied in recent years. Upon encapsulation, biomolecules retain their spectroscopic properties and biological activity. Sol-gel matrices are thermally and chemically stable and can be obtained in a variety of forms, such as optically transparent monoliths, granulates, microparticles or thin films. Sol-gel immobilization is characterized by physical entrapment without chemical modification. Immobilizing substances by physically trapping in individual pore of a matrix permits their molecules to be isolated and stabilized. The advantages of sol-gel encapsulated biologicals might give them applications such as optical and electrochemical sensors, diagnostic devices, catalysts, and even bioartificial organs. While the relatively large biomolecules are immobilized within the silica network, small ions or molecules are transported into the interior of the matrix.

7

Selected issues of non-conventional enzymology Part I. ? Characterization of enzymatic processes carried out in a medium with subcritically low water content

80%

Antczak T. , Szczesna-Antczak M.

Biotechnologia

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2003

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nr 3

124-138

EN

Enzymology of non-aqueous media, also termed a non-conventional enzymology, is a discipline focused on chemical reactions catalysed by enzymes in the media other than water. However, such environments always contain certain amount of water, either dissolved in a solvent or enzyme-bound. The latter fraction of water is called an essential one, and it is crucial for the non-aqueous enzymology, since it stabilises the conformation of protein molecule and determines its enzymatic activity. The paper presents structure, function, and methods of assays of the enzyme-bound water together with other water forms that can also be found in reaction milieu. The methods of regulation of enzymatic activity in non-aqueous media by using compounds capable of associating with polar atoms of amino acid residues involved in catalysis, and thus positively influencing activity of enzymes, have also been discussed. The factors giving rise to a decrease in catalytic activity of enzymes under non-aqueous conditions, and methods of prevention against this phenomenon have also been analysed.

8

Protein microencapsulation ? methods and application

80%

Piasecka A. , Goderska K.

Biotechnologia

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2010

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nr 1

34-45

EN

Biomaterials extracted from natural environment may cause several serious problems due to their low stability. More efficient and safe procedures of their stabilization are still demanded to meet the industry requirements. Microencapsulation is one of the possible methods to prolong the action time of active compounds. This paper reports the techniques for preparing microcapsules and their applications with reference to extremely troublesome materials such as native proteins. Special attention is paid to current achievements in microencapsulation and perspectives for the next years, and advantages of this technique. The technology enables reactive or sensitive biomaterials such as enzymes to be turned into stable ingredients. With carefully controlled and fine-tuned release capabilities, microencapsulation is no longer only an added value technique, but the source of totally new systems with matchless properties.

9

Enzymes involved in polymer biodegradation

80%

Nowak B. , Pajak J. , Plociniczak T. , Labuzek S.

Biotechnologia

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2008

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nr 1

45-52

EN

Most widely used plastics are considered to be resistant to environmental factors. Degradation of most popular packaging polymer is slow and may take hundreds of years. To enhance their environmental degradation a number of different approaches, among them copolymerisation or compounding with additives susceptible to environmental factors such as polyesters are used. Enzymes involved in decomposition of polyesters are mainly hydrolases f.ex. esterases, lipases, cutinases. Research team in the Department of Biochemistry is working on polyethylene and poly(ethylene terephtalate) films modified with synthetic aliphatic polyester Bionolle? and mechanisms of their biodegradation using fungal extracellular hydrolytic enzymes.

10

Microbiological transformation of organic matter in estuarine basins of the Polish coast.III.Activity of proteases, amylases and lipases synthetized by bacteria isolated from maritime lakes

80%

Mudryk Z.

Oceanological Studies

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1995

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nr 69/10

33-44

EN

This paper presents the results of investigatoins on activity of proteases, amylases and lipases synthetized by estuarine bacteria.The highest lavels of activitry of the enzymes studied were observed in bacteria from hypertrophic lake Jamno, the lowast in bacteria from eutrophic lake Lebsko.The activity of the enzymes displayed substantial seasonal fluctuations.The marked impact of pH and salinity on the level of the enzymatic activities was also noticed.

11

Suitability and properties of beta-galactosidases from different sources

80%

Synowiecki J. , Maciunska J.

Biotechnologia

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2000

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nr 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.

12

Application of supercritical fluid technology in bioprocess engineering

80%

Malinowski J. , Jarzebski A.

Biotechnologia

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1996

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nr 3

87-96

EN

An overview of the prospects for application of supercritical fluid technology in bioprocess engineering is given.Recent investigations on the application of dense gases in biocatalysis particles formation, separation and purificatiob of biologically active compounds are critically reviewed.

13

Biotechnological methods of synthesis of biosurfactants Part I. Enzymatic synthesis of surfactants

80%

Bednarski W.

Biotechnologia

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1999

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nr 4

7-23

EN

Surface active agents (surfactants) are generally amphiphilic substances consisting of hydrophobic and hydrophilic moieties. They have many applications in the food, cosmetics, and pharmaceutical industry, pollution control, etc. Lipases (EC 3.1.1.3; acyloglycerol hydrolase) have many applications and they are able to catalyze synthesis of biosurfactants ie. mono- and diacyloglycerols, carbohydrate esters of fatty acids etc. These products are biodegradable, natural, non-toxic and aceptable by consumers. In this article enzymatic methods of synthesis of biosurfactants are presented.

14

The activity of selected hydrolases in excretion-secretion products and exctracts from larvae and mature specimens of Cystidicola farionis

80%

Dziekonska-Rynko J. , Rokicki J. , Jablonowski Z.

Oceanological and Hydrobiological Studies

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2003

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nr 4

117-129

EN

The results of the study indicated that there are differences in the activity of hydrolases depending on the development stage of the parasite and the season of the year. Twelve hydrolases were confirmed to be active in excretion-secretion (ES) products of larvae collected in fall, while nine were active in spring. The activity of hydrolase from the extracts of fall samples was most often higher than in spring. Eight active hydrolases were confirmed in mature specimens both in spring and fall, and they exhibited a lower activity level than the ES products of larvae. However, the activity of enzymes was higher in mature specimens than in larvae in the extracts from both spring and fall samples.

15

Genes and enzymes taking part in biotransformation of steroid ring structure

80%

Brzostek A. , Poplawski T. , Murooka Y. , Dziadek J.

Biotechnologia

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1998

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nr 2

67-85

EN

Biotransformation of steroid compounds involves two major steps: side chain degradation, which is poorly understood at the genetic level, and the degradation of steroid ring structure, which is better known. This article describes well known molecular mechanisms of ring structure multistep biodegradation. Particular stress is put on the role of cholesterol oxidase, ketosteroid dehydrogenase, ketosteroid isomerase as the best analysed enzymes involved in steroid biotransformation.

16

Effect prolonged administration of insecticide-cyhalothrin/karate on the blood and liver of rabbits

80%

Shakoori A. R. , Aslam F. , Sabir M. , Ali S. S.

Folia Biologica

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1992

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tom 40

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nr 1-2

91-99

EN

A sublethal dose of Karate administered to rabbits produced a signification increase in the total erythrocyte count and packed cell volume after 15 days of administration, though no significant change was observed after 30 days. The transaminases (glutamate oxaloacetate transaminase, GOT; glutamate pyruvate transaminase, GPT) also increased after 15 days of treatment. The GPT activity increased 119% and 60% after 15 and 30 days, respectively. From amongst metabolites, glucose content increased 17% and 185%, while cholesterol decreased 40% and 66%, and bilirubin 84% and 61%, after 15 and 30 days, respectively. The hepatic AkP activity decreased 30%, while the GPT activity increased 44%. Other enzymes such as AcP, GOT and LDH remained unaffected. The concentration other metabolites, except for FAA which increased 35%, remained unaffected. Histological changes were marked by atrophied hepatic cells and hypertrophied nuclei and nucleoli. A trend towards necrosis of hepatic cells was also observed. All these results indicate that Karate is moderately toxic to mammals.

17

Biofuel cells

80%

Karnicka K. , Kowalewska B. , Miecznikowski K. , Kulesza P. J.

Biotechnologia

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2007

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nr 4

25-37

EN

The concept of a biofuel cell, basic principles of operation, historical and present achievements as well as types of biofuel cells are described here. In principle, a biofuel cell can be considered as a special type of an electrochemical fuel cell in which, instead of noble-metal (e.g. Pt) type catalytic electrodes, biocatalysts in a form of microorganisms or enzymes are used. Consequently, biofuel cells operate under milder conditions (neutral electrolytes, ambient temperature and pressure) in comparison to conventional fuel cells. Typically, such biofuels as ethanol, glucose, formic acid or lactic acid are utilized on the anodic side. To make biofuel cells practically more attractive, there is a need to improve cathode and develop stable and effective bioelectrocatalytic systems for the oxygen reduction. Depending on whether the biocatalyst (enzyme) exists in living organisms (bacteria) or in the isolated form, biofuel cells can be divided into microbial and enzymatic ones. Another important issue is whether the biocatalyst is immobilized on the electrode surface or it is dissolved in solution (and subject to diffusional mass transport). Further, depending on a mechanism of charge propagation and distribution (electron) to the biocatalytic active sites, biofuel cells can be distinguished in terms of systems utilizing mediators (MET or mediated electron transfer type) or operating without mediators (DET or direct electron transfer type). Recently, there has been growing interest in biofuel cells because of the environmental concerns and, primarily, due to the necessity of searching for novel alternate energy resources.

18

Biotechnology in Polish food science ? achievement and perspectives

80%

Grajek W.

Biotechnologia

|

2002

|

nr 4

41-55

EN

Polish food biotechnology science has achieved many successes in past years. Many new technologies have been introduced into food industry and many new products have been offered to consumers. The research related to food biotechnology is concentrated on agricultural universities, technical universities and on branch institutes. Although traditional biotechnology in Poland appears to be well developed, there are many groups working on transgenic plants and animals. In general, only few modifications concern the features important for food applications.

19

Genetic variability among beech (Fagus sylvatica L.) populations from the Sudety Mountains, in respect of peroxidase and malate dehydrogenase loci

80%

Krzakowa M. , Matras J.

Journal of Applied Genetics

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2005

|

tom 46

|

nr 3

271-277

EN

Individual trees growing in five populations of European beech (Fagus sylvatica L.) in the Sudety Mountains were investigated in respect of variability of peroxidases (2 loci) and malate dehydrogenase (1 locus). Differences between populations were illustrated by a dendrogram constructed on the basis of Hedrick's (1974) genetic distances. The mean GST coefficient (=0.0333) value demonstrated the higher level of intra-population variability, as compared to the inter-population (DST = 0.0149) variability.

20

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

80%

Sinkiewicz I. , Synowiecki J.

Biotechnologia

|

2009

|

nr 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.