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1

Biotechnology in Polish food science ? achievement and perspectives

100%
Grajek W.
Biotechnologia
|
2002
|
issue 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.
2

Factors influencing expression of recombinant genes in vitro in Escherichia coli.Part I - Construction of expression system

100%
Grajek W.
Biotechnologia
|
1995
|
issue 1
91-102
EN
E.coli is the most frequently used host-organism for production of heterologous protein from cloned genes.Proper costruction of expression vector is a key factor succesful expression.It should ensure a good segregational stability as well as quarantee induced and regulated gene expression.The most important DNA sequences in he expression vectors are discussed.Gene dosage effect, amplification of recombinant genes, regulation of DNA replication and transcription are described in relation to plasmid stability.
3

Factors influencing expression of recombinant genes in vitro in Escherichia coli.Part II.Culture conditions in bioreactor

100%
Grajek W.
Biotechnologia
|
1995
|
issue 1
103-113
EN
High expression yield and high volumentric productivity off fermentations emploing recombinant E.coli need special processing.For recombinant protein production two strategies can be applied.One is to carry out one step fermentation with simultanous gene expression and elimination of vector-less segregants.the other is to carry out two step fermentation, in which the first step is the call biomass production without gene expression followed by the induction of gene expression in the second step.In this review different methods of controlling of recombinant gene expresson, such as antibiotic pressure, specific mutant appliction, immobilized cell bioreactors, selective cell recylculation, chemical regulations, the use of temperature and oxygen sensitive promoters are presented.
4

Biotechnology education in Poland

100%
Grajek W.
Biotechnologia
|
1993
|
issue 4
96-106
EN
In the 1980s biotechnology was included in the curricula of Polish universities and polytechnics.At the moment there are over 7 hundred students of biotechnology related faculties. Food and environmenental biotechnology is the most popular specialization in biotechnological education.Hovever, relatively few continue their studies at the Ph.D.level.
5

Lactic acid bacteria cellular responses for enviromental stress

64%
Sadowska J., Grajek W.
Biotechnologia
|
2009
|
issue 4
115-132
EN
Lactic acid bacteria (LAB) constitute a heterogeneous group of bacteria that are traditionally used to produce fermented foods. The industrialization of food biotransformations increased the economical importance of LAB. The development of new applications such probiotic foods reinforces the need for robust LAB. They have to survive in the digestive tract, and express specific functions under conditions that are unfavorable to growth. A better understanding of the mechanisms of stress resistance and LAB cellular responses should allow to prepared these bacteria for industrial processes. Range of examples of diferent enviromental stress, related genes and molecular mechanisms of the stress responses are presented.
6

The influence of environmental stresses on Saccharomyces cerevisiae yeast in ethanol fermentation

64%
Grajek W., Szymanowska D.
Biotechnologia
|
2008
|
issue 3
46-63
EN
The development of ethanol fermentation process brings numerous environmental stresses influenced by the survival and metabolism of industrial microorganisms. Saccharomyces cerevisiae strains have evolved to survive constant fluctuation in their external surroundings by special adaptation systems. These adaptation mechanisms involve reorganization of genomic expression by activation of transcriptional factors under stress conditions and production of suitable metabolites increased by cell survival. This review is focused on the metabolism and genetic response of cells to diverse environmental changes, especially to heat, osmotic, ethanol, oxidative, toxic and other physic-chemical stresses.
7

The influence of factors on baculovirus / insect cell system productivity

64%
Olejnik A., Grajek W.
Biotechnologia
|
2003
|
issue 1
158-175
EN
The baculovirus expression vector system (BEVS) is a powerful tool for the heterologous protein production. The productivity of BEVS depends on: insect cell lines and their growth parameters, medium composition, multiplicity of infection (MOI), time of infection (TOI), quality of viral inoculum and scale of cultivation. The factors influencing foreign gene expression level in BEVS ? were the subject of the presented review.
8

Analysis of physiological state of single bacterial cell using fluorescent staining methods

64%
Sadowska J., Grajek W.
Biotechnologia
|
2009
|
issue 4
102-114
EN
The paper reviews fluorescent staining techniques allowing to diagnose the physiological state of bacterial cells. Different staining probes and a manner of their use for analysis of cell viability, membrane potential, membrane integrity, intracellular pH, respiratory activity, amount of nucleic acids, and activity of chosen intracellular enzymes are described. Range of examples of fluorescent staining for monitoring of physiological state of bacteria in natural environment and in biotechnological processes are presented.
9

Energy-saving and by-products-free production of ethanol from granular corn starch

64%
Szymanowska D., Grajek W.
Biotechnologia
|
2011
|
issue 1
85-91
EN
Intense development of the transport sector and a rise in the prices of fossil fuels boost the demand for fuels from alternative sources of energy, including biofuels. Thus, new energy-efficient technologies of fuel production from renewable resources are being developed. Accordingly, we attempted to create a technology of bioethanol production by simultaneous enzymatic hydrolysis and fermentation of native corn starch. In our work we used commercially available STARGEN 001 enzymatic preparation for native corn starch hydrolyzis, and yeast Saccharomyces cerevisiae strain Red Star Ethanol Red for it's fermentation. A major part of the research was on developing a fermentation technology with repeated full recirculation of stillage liquid fraction. It has been shown that a completely effluentless ethanol production with separation of stillage solid fraction and using the liquid fraction to prepare the next portion of corn mash is possible. Thus the process can proceed for several months without any effluent.
10

Biotechnology of insect cell tissue culture

64%
Olejnik A., Grajek W.
Biotechnologia
|
2003
|
issue 1
176-192
EN
The commercial exploitation of the baculovirus expression system for heterologous protein or biopesticides production requires an efficient large-scale cultivation method. This review summarized recent developments concerning the scale-up of insect cell culture and baculovirus gene expression. We described novel bioreactor systems (stirred tank bioreactor, bioreactor airlift and cell-lift, membrane bioreactor), culture modes (batch, fed-batch, continuous) and different strategies used for cell cultivation and baculovirus replication.
11
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Energy-saving and by-products-free production of ethanol from granular corn starch

64%
Szymanowska D., Grajek W.
BioTechnologia
|
2011
|
issue 1
12

Conditions and perspectives of agrobiotechnology development in Poland

52%
Legocki A. B., Grajek W., Switonski M., Twardowski T.
Biotechnologia
|
1995
|
issue 1
11-17
EN
The report describes biotechnological aspects of plant and animal breeding, food production and legal regulations in Poland.The conditions and perspectives of development are discussed.
13

Kinetics of biological iron oxidation in immobilized packed-bed reactors

52%
Nawrocki J., Wisniewski P., Grajek W., Astrib M.
Biotechnologia
|
1995
|
issue 2
141-152
EN
A packed-bed bioreactors with activated carbon particles as a cerrier for iron-oxidizing bacteria was used for ferrous sulfate oxidation.The bioreactors were operated continuously for about 2 weeks.The experimental variables were: dillution rate, pH, medium composition and Fe(II) ions concentration.It was found that the efficiency of iron oxidation depended on the dilution rate and the medium pH.As dilution rate increased, the oxidation rate was decreased but at the same time reacto productivity was improved.The highest kinetic performance achieved in single stage fermentation related to the Fe(II) oxidation was over 90% when D was below 0.2/h.The pH optimum was 1.3. At higher pH values a ferric iron precipitation was accelerated.It was showed thet replacement of the 8K medium with tap water has not had a negative effect on iron oxidation process.
14

Optimization of simultaneous saccharification and fermentation of the native starch by using response surface method

52%
Bialas W., Wojciechowska D., Szymanowska D., Grajek W.
Biotechnologia
|
2009
|
issue 4
183-199
EN
Ethanol production, by a simultaneous saccharification and fermentation process (SSF) of native starch from corn flour, has been performed by Saccharomyces cerevisiae (Ethanol Red) and granular starch hydrolyzing enzyme (STARGEN 001). The quantitative effects of mash concentration, enzyme dose and pH were investigated by the use a Box?Wilson central composite design protocol. It was found that for native corn starch, maximum ethanol concentration of 110,36 g/l was obtained using a mash concentration of 25%, which resulted in ethanol yield of 85,71%. The optimum conditions for the above yield were found for the enzyme dose of 2,05 ml/kg and pH of 5.0. These results indicated that by using the central composite design, it is possible to determine accurate values of the fermentation parameters for maximum ethanol production.
15

Public perception of biotechnology in Poland; Dynamics of changes in 1998-2000

52%
Twardowska-Pozorska A., Grajek W., Twardowski T.
Biotechnologia
|
2001
|
issue 1
87-100
EN
Public perception of biotechnology in Poland in years 1998-2000 was surveyed. In the survey in general the scheme of research of Eurobarometer was followed. Based on the data of last three years the changes of the opinion of Polish society in comparison to the European data were presented. About 10% reduction of the public trust and willingness to accept biotechnology was found in all social groups, except well educated, well finances group, aged 20-30 years. The conclusion is simple only the social, permanent education will improved public perception of modern technology.
16

Epithelial cell cultures as a model system to study the transepithelial transport

52%
Grajek W., Olejnik A., Staniaszek K.
Biotechnologia
|
2006
|
issue 2
148-165
EN
Epithelial cell lines are commonly accepted model system to determine intestinal permeability and transepithelial transport. The application of Caco-2 human epithelial cell culture can be used to study bioavailability of drug and food compounds. This culture grows on porous membranes and forms a monolayer of well differentiated cells joined by intracellular tight junctions. This system provides selective barrier to study passive and active transport of different molecules. The Caco-2 cells posses some enzymes and transport systems similar to intestinal epithelium in vivo, however, these proteins are expressed to a lesser extent compared to normal enterocytes. In this paper, the advantages and limitations of Caco-2 model are discussed.
17

What Polish people know about modern biotechnology

52%
Twardowska-Pozorska A., Grajek W., Twardowski T.
Biotechnologia
|
2001
|
issue 4
115-121
EN
Continuing our research on public perception of modern biotechnology in Poland this time we surveyed the knowledge of modern biotechnology between Poles. The representative sample of Polish society (over 1000 Poles aged over 15 years) answered questions like: did you eat genes for breakfast?, are genes in tomato?, is BSE a product of genetic engineering? We found surprisingly good familiarity (awareness) of background biotechnology. Over 40% of Poles know that all tomatoes contain genes, over 20% eat genes for breakfast and one third know that BSE is not a result of genetic engineering.
18

Biological methods of ferric sulphate coagulant production with Thiobacillus ferrooxidans

52%
Wisniewski P., Nawrocki J., Grajek W.
Biotechnologia
|
1995
|
issue 3
140-151
EN
A packed-bed bioreactor with activated-carbon particles as a carrier matrix material inoculated with Thiobacillus ferroxidans was operated at a pH 1.30 to convert ferrous sulfate to ferric sulfate.The experimental variables were dillution rate, medium composition and Fe (I) ion concentration.The reactors were operated within a dillution rate range of 0.013 to 0.560/h and within a ferrous sulfate concentration range of 20 to 40 g/l.The aeration rate was 5-7 l/h.It was showed that replacement of the 9k medium with tap water had no negative effect on iron oxidation process.
19

Growth kinetics of embriogenic and nonembriogenic suspension cultures of cucumber (Cucumis sativus L.) in stirred bioreactor

52%
Kroliczak P., Grajek W., Tomkowiak M.
Biotechnologia
|
1995
|
issue 3
152-166
EN
Embryogenic and nonembriogenic suspension cultures of cucumber were cultivated in a 5-L stirred bioreactor.Significant differences between kinetic characteristics of these cell lines (growth rate, tissue morphology, sugar and nitrogen metbolism) are presented. Nonembryogenic culture demonstrated faster growth rate anr greater nutrient uptake.Mechanical sterss in stirred bioreactor under experimental conditions was negligible.
20

Bioethanol production from cellulose raw material

52%
Leja K., Lewandowicz G., Grajek W.
Biotechnologia
|
2009
|
issue 4
88-101
EN
Lignocellulose is a potential non-food raw material for production of bioethanol. Its use gives the world economy a chance to be independent from petrochemical industry. In the last decade, interest in bioethanol production from waste raw materials increased. However, production processes require more research in order to optimize production conditions and decrease its cost. In each production stage, there appear various problems, for example, a selection of hydrolysis enzyme and microorganisms leading to fermentation. Probably, in the near future, the productivity of bioethanol from waste materials will improve.
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