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1

From DNA sequence to antibiotic

100%
Pawlik K., Kotowska M.
Biotechnologia
|
2005
|
issue 3
57-74
EN
Progress in molecular biology, large number of known bacterial sequences and a number of microbiological genome sequencing projects finished or running allow to think about creating in vitro the DNA code in order to obtain new metabolites. Here, we describe the attempts of biosynthesis of new polyketides by designing new genes coding polyketide synthases. In assembling new polyketide synthases, the fragments of known genes are widely used. High homology of the polyketide synthase genes and a number of known produced polyketides give a possibility to describe a polyketide synthase on a DNA sequence level. Basing on known amino acid motifs, it is possible to determine enzymatic activities acting in the process of polyketide synthesis, and so to predict putative structure of the final metabolite. Successful artificial synthesis of 6-deoxyerythronolide B synthase genes show how near is the realization of the idea of producing new chemical compounds by creating DNA information.
2

On-line monitoring of A. niger metabolic activity in biotransformation of glucose to gluconic acid

100%
Podgorski W.
Biotechnologia
|
2004
|
issue 1
169-186
EN
Control parameters directly connected with metabolism of microorganism that reflect its actual activity in gluconic acid biosynthesis can be chosen basing on mass balance of the process. The relatively high correlation between parameters, normally determined via sample analysis and microorganisms? respiratory activity, enabled on-line estimation of biomass growth, product formation, and substrate uptake rate. The estimated parameters were continuously measured and employed to on-line control of gluconic acid overproduction by Aspergillus niger W78B strain. The application of the noninvasive technique for parameters determinations allowed obtaining high effectiveness of product formation characterized by the yield coefficient that equals 1.0 g g-1 and product formation rate amounted to 5 g dm-3 h-1. The estimation of the parameters cannot be used instead of their quantitative determinations, but it gives a possibility of on-line monitoring and control of the process.
3

Differential expression of candidate genes for lignin biosynthesis under drought stress in maize leaves

100%
Hu Y., Li W.-C., Xu Y.-Q., Li G.-J., Liao Y., Fu F.-L.
Journal of Applied Genetics
|
2009
|
vol. 50
|
issue 3
213-223
EN
In order to provide information for the development of molecular selection markers for drought tolerance improvement, the methods of prometric analysis, quantitative real-time PCR and field evaluation were employed for the identification of the differential expression of candidate genes under drought stress in maize. At seventeen, twenty-four and forty-eight hours of polyethylene glycol-simulated drought stress at the seventh leaf stage, leaf samples were collected from two drought-tolerant inbred lines for prometric analysis by two-dimensional electrophoresis and peptide mass fingerprinting. Fifty-eight proteins out of more than 500 were found in response to drought stress. Three drought-induced spots 2506, 3507 and 4506 showed sequence similarity with cinnamyl alcohol dehydrogenase, cytochrome protein 96A8 and S-adenosyl-L-methionine synthase, respectively. The expression of two key enzymes to lignin biosynthesis was quantified by quantitative real-time PCR among three drought-tolerant and one drought-sensitive inbred lines under drought stress and well-watered control conditions. After a decrease at the beginning of drought stress, the expression of cinnamyl alcohol dehydrogenase and caffeate O-methyltransferase recovered at twenty-four hours of the drought stress in the three drought-tolerant lines, but not in the drought-sensitive lines. Leaf lignin content, anthesis-silking interval and grain weight per plant were investigated with six inbred lines of varying drought tolerance under drought stress and well-watered control. Drought tolerance coefficients of these three characters were calculated and the correlation coefficients among these drought tolerance coefficients were estimated. Significant difference in leaf lignin content was found among the inbred lines and in response to drought stress. Close correlations were observed between the drought tolerant coefficients for leaf lignin content and grain weight per plant, and between the drought tolerant coefficients for leaf lignin content and anthesis-silking interval. These results indicate that leaf lignin content is a useful index for evaluation of drought tolerance in maize. Molecular selection markers can be developed on the basis of differential expression of the candidate genes and applied to maize improvement for drought tolerance.
4

Ethylene and bacteria

100%
Kepczynska E., Zielinska S., Kepczynski J.
Biotechnologia
|
2000
|
issue 1
147-155
EN
The review article presents data on the ethylene emanation by bacteria, the two different pathways of its biosynthesis in these microorganisms and the role of ethylene in plant pathogenesis. ACC deaminase from Pseudomonas and Enterobacter spp., which catalyses the hydrolytic cleavage of ACC in higher plants was also discussed.
5

Biosynthesis of gallic acid and its application

100%
Guzik U., Wojcieszynska D., Jaroszek P.
Biotechnologia
|
2010
|
issue 1
119-131
EN
Gallic acid belongs to aromatic plant substances (poliphenols). Two main biosynthesis pathways in plants of this compound were described as shikimate and polyketide pathways. Gallic acid is applied in agriculture, where it is used as inhibitor of aflatoxin produced by Aspergillus. Gallic acid is also used in food manufactur, as antioxidant, sweetener or antiseptical and antifungal substance. Furthermore, gallic acid effectively prevents and inhibits diseases' progress. It can be used in the therapy of diabetes type II, neoplastic and allergic diseases or in treatment of arteriosclerosis.
6

L ? lysine biosynthesis

100%
Golabczak J.
Biotechnologia
|
2008
|
issue 1
53-70
EN
Amino acid fermentation has grown into a global industry. Market development has been particularly dynamic for the flavor-enhancer glutamate and animal feed amino acids: L ? lysine, DL ? methionine, L ? threonine, and L ? tryptophan. These amino acids are manufactured using high performance Corynebacterium glutamicum. Production strains have been traditionally constructed by repeating random mutation and selection. This classical method has generated a variety of mutation, such as auxotrophs, analog-resistant mutants and transport mutants. The complete genome sequence of the wild-type strain of C. glutamicum has been established and analysed to improve the understending of the molecular biology and physiology of this organism. A novel methodology that merges genomics with classical strains improvement has been developed and applied for the reconstruction of classicaly derived production strains. In addition, modern technologies such as metabolic flux analysis and metabolic control analysis have enabled quantification of carbon fluxes. The fundamental information obtained has been the basis for further strain improvement.
7

N-nitrosodimethylamine ? toxicological aspects

100%
Jablonski J.
|
EN
In this paper we have presented data on an environmental exposure to N-nitrosodimethylamine (NDMA) and factors which favour endogenoeaus biosynthesis of this compound. The factors influencing metabolism and toxicity as well as health effect of exposure have been reported.
8

Selenocysteine - 21st.amino acid of the universal genetic code

100%
Pawelkiewicz J.
|
EN
Biosynthesis and properties of selenocysteine - 21st amino acid of the diverse genetic code are discussed.New structural pecularities of Sec-tRNA ser as mRNA are crucial for incorporation of selenocysteine into some proteins.Pseudoknot structure can be formed within mRNA and play a regulatory role in translation.
9

Secondary metabolites from transformed root cultures

100%
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.
10

Intensification of lipase biosynthesis as a result of electrofusion of Rhizopus cohnii protoplasts

100%
Sawicka-Zukowska R., Juszczakiewicz D., Misiewicz A., Krakowiak A., Jedrychowska B.
Journal of Applied Genetics
|
2004
|
vol. 45
|
issue 1
37-48
EN
Our objective was to obtain products of fusion of the filamentous fungus Rhizopus cohnii Rh.c./1 with an increased capacity for lipase biosynthesis in comparison with the original strain. Protoplasts of auxotrophic mutants of the parent strain Rh.c./1 obtained after UV irradiation of the spores were subjected to electrofusion. We found that the largest number of electrofusion products could be obtained with the use of the following process parameters: 1 or 2 impulses immediately following one another with a field intensity of 200 V/cm and an exposition time of 1000 ms at the stage of dielectrophoresis, 1 impulse with a field intensity of 500 V/cm and an exposition time of 10 ms or 20 ms at the stage of fusion, regulated temperature of 4oC before and after the process, rounding time of ca 20 min. Electrofusion of protoplasts of auxotrophic mutants of the Rh.c./1 strain produced 19 fusion products whose lipase biosynthesis capacity in a liquid medium culture was higher than that of the parent strains. The fusion product labelled XIII-21 was selected as the best strain. Lipase activity obtained after its culture in the liquid medium was ca 3.5 times higher than that obtained after the culture of the original strain Rh.c./1.
11

Biochemical and molecular characteristics of bacteriocins produced by Propionibacterium

88%
Gwiazdowska D.
Biotechnologia
|
2010
|
issue 3
75-93
EN
Bacteriocins are antimicrobial proteins or peptides produced by both Gram-positive and Gram-negative bacteria. Many of these metabolites are active towards closely related species, but some of them are able to inhibit bacteria not related with bacteriocin producer, including food pathogens such as Listeria monocytogenes or Clostridium botulinum. The most studied bacteriocins are those produced by lactic acid bacteria, but an increased interest in bacteriocins synthesized by propionibacteria has been observed in the last years. In this paper, the data on molecular characteristics and biochemical properties of actually known bacteriocins produced by this group of bacteria is presented.
12

Human gastrointestinal tract mucins encoded by the MUC gene family

88%
Paszkiewicz-Gadek A., Porowska H.
Postępy Higieny i Medycyny Doświadczalnej
|
2000
|
vol. 54
|
issue 2
183-198
EN
Epithelial mucins, MUC gene products, are widely expressed in human organs such as airwais, the urogenital and gastrointestinal tracts, and the eyes. MUC-type mucins have very large sizes and comlex structures with very extensive O-glycosylation and are regarded as protective molecules. The aim of this review is to discuss mucin glycoproteins structure, biosynthesis and functions in normal and pathologicaly altered epithelial mucosa of human gastrointestinal tract.
13

- new AA-derived molecules

88%
Stajszczyk M., Gaminski J.
Postępy Higieny i Medycyny Doświadczalnej
|
1993
|
vol. 47
|
issue 2
133-145
EN
The paper deals with the current state of knowledge on . The , multiple biosynthesis pathways, possible mechanisms of action, and participation of lipoxins in are characterised.
14

Oxygen transfer during citric acid biosynthesis in 7 and 15 000 liters stirred tank reactors

88%
Podgorski W., Lesniak W.
Biotechnologia
|
2004
|
issue 1
187-200
EN
In laboratory scale, submerged citric acid fermentation enabled to obtain similar to the industrial bioreactor volumetric oxygen transfer rate (kLa) amounted to 240 h-1. Nevertheless, such level of kLa seems not to be necessary for the process. Bioreactors used for the production of citric acid using Aspergillus niger W78B strain, assuring kLa at the 120 h-1 level in a overproduction phase, allowed achieving the oxygen uptake rate by cells in the range 12-15 mmol dm-3 h-1 and a product on substrate yield factor (YP/S) higher then 0.8 g g-1. Thus, the resignation from the widespread in literature strategy of pO2 maximization as an essential prerequisite for high citric acid yield, allowed obtaining the significant 20% improvement in the yield of product formation in the case of molasses media and 7% on synthetic one. Therefore, it can be stated that excessive media aeration during submerged citric acid biosynthesis is not suitable for yield and/or cost of product formation.
15

Effect of carbon source on inducing biosynthesis of amylases by Lactobacillus plantarum and Lactobacillus amylovorus

88%
Zielinska K. J., Stecka K. M., Grzybowski R. A., Suterska A. M.
|
EN
We studied the effect of polysaccharides: native and soluble potato starch, amylopectin, amylose, dextrin and maltodextrin, disugars ? maltose, saccharose and lactose, and of simple sugars ? glucose, mannose and xylose on intensity of biosynthesis of amylases, being expressed as an activity of alpha-amylase and glucoamylase, contained in the liquid after cultivation of bacteria strains: Lactobacillus plantarum K, Lactobacillus plantarum C and Lactobacillus amylovorus. It was found that native and soluble potato starch, being used as the only source of carbon in culture medium, stimulated the process of amylases biosynthesis by the examined bacterial strains. The highest level of alpha-amylase activity, equal to 13-14 JA and of glucoamylase ? 0,37-0,39 JGA in 1 ml of post-cultivation liquid was obtained after 72 h of cultivation of Lactobacillus plantarum K and Lactobacillus plantarum C when the native potato starch was the only source of carbon in medium. Lactobacillus amylovorus strain synthetised amylases with the highest level of alpha-amylase activity, amounting to 17 JA and glucoamylase ? 0,24 JGA/ml of post-cultivation liquid, after 72 h of cultivation when the potato starch was the only carbon source in the medium. On the other hand, when the native potato starch was used, the activity of alpha-amylase was equal to 9 JA and that of glucoamylase 0,09 JGA in 1 ml of post-cultivation liquid. The amylolytic activity in post-cultivation liquids was increased to smaller extent when the carbon source in culture of the examined bacterial strains was dextrin, maltodextrin, saccharose, maltose or mannose.
16

Biosynthesis of bacterial cellulose and its application

75%
Krystynowicz A., Turkiewicz M., Drynska E., Galas E.
Biotechnologia
|
1995
|
issue 3
120-132
EN
Biosynthesis of bacterial cellulose and its potential applicationa are presented.The mechanism of cellulose biosynthesis in Acetobacter xylinum, the regulatory pathways and the polymer structure are described.Some biotechnological aspects of polysaccharide production and industrially valuable features of bacterial callulose are also discussed.
17

Microbial conversion of plant waste lipids

75%
Tomasik J., Bednarski W., Kowalewska E.
Biotechnologia
|
1993
|
issue 3
196-207
EN
after solvent refining process were used as a carbon source for cultivation of and ATCC 20509. Biomass yield varied from 3.8 g d.m./l to 19.9 g d.m./l and lipids yield varied 1.0 g/l to 10.6 g/l. Lipids utilization in medium varied from 15.0% to 85.4%. Process efficiency, and percentage composition of fatty acids of intracellular lipids and grease remaining in the medium depend first of all on medium composition, type of microorganisms used, temperature and time cultivation.
18

Xanthohumol and other prenylated flavonoids of hop cones ? biological and technological aspects

75%
Golabczak J., Gendaszewska-Darmach E.
Biotechnologia
|
2010
|
issue 1
82-96
EN
Hops, the female inflorescences of the hop plant (Humulus lupulus) are used in the brewing industry to add bitterness and aroma to beer. This raw material is a rich source of terpenoid essential oils and terpenophenolic resins (bitter acids, prenylated flavonoids). Xanthohumol is the most abundant (80-90%) of total amount of prenylated flavonoids in hop cones (up to 1% w/w). Xanthohumol has received much attention in recent years as a cancer chemopreventive agent because of its ability to inhibit initiation, promotion and progression stages of carcinogenesis. It's beneficial effects on health also include antibacterial, antioxidant, and antiinflamattory properties. Hydrophobic xanthohumol cannot be extracted with carbon dioxide under condition used for common hop extract destined for the application in the brew house (300 bar, 50?). This flavonoid remains in the waste product of the hops (spent hops) processing industry. Diverse extraction methods of spent hops by ethanol and supercritical CO2 at different pressures lead to the residues that contain more than 30% xanthohumol. The multistep process extraction and separation of xanthohumol from natural source (raw or waste hops) with organic solvent have been also conducted. Recently, a synthetic route to xanthohumol has also been described. The purpose of this review is to provide an overview of the chemistry, biosynthesis, biological activities, and biotechnological aspects of xanthohumol.
19

Structure, medicinal properties and biosynthesis of cyathane diterpenoids

75%
Wojciech K., Eliza M., Franciszek H.
Biotechnologia
|
2008
|
issue 1
146-167
EN
This paper describes an unusual type of diterpenoids, called cyathins, and presents their structure, biosynthesis and biological activities. These secondary metabolites have been isolated during the last 35 years from mycelia, culture broths and fruiting bodies of several species of mushrooms such as Cyathus helenae, C. striatus, Hericium erinaceum and Sarcodon scabrosus. Cyathane diterpenoids are known to have a potent stimulating effect on Nerve Growth Factor synthesis and can became potential therapeutic agents for the treatment of neurodegenerative disorders, for instance Alzheimer's disease. Cyathins also posses anti-imflammatory and antimicrobial activity.
20

Lignin - distribution, biosynthesis, preparation and structure

75%
Leonowicz A., Rogalski J., Wojtas-Wasilewska M., Luterek J.
Biotechnologia
|
1995
|
issue 1
158-175
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