Search results

1

Biogenic catalysis in sulphide minerals' weathering processes and acid mine drainage genesis

100%

Kušnierová M., Praščáková M., Nowak A., Gorazda K., Wzorek Z.

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2014

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vol. 61

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issue 1

33-39

EN

Bioleaching and biogenesis are the main outputs from a large group of environmental processes participating in the natural material cycle, used in raw materials processing. Bio-oxidation reactions are the main basis for bioleaching procedures, often participating in parallel leaching processes. During the leaching processes of polycomponent sulphide substrates, the factor of process selection also plays an important role, being in direct relation to the electric properties and galvanic effect occurring between the individual components of the leaching substrate. This work gives a summary of the results of a research focused on the possibilities of using biotechnological procedures for treatment of Slovak sulphide ores. The object of the research is extraction of valuable metals, undesirable admixtures and degradation of crystal lattice of sulphides for subsequent chemical leaching processing of precious metals. The results of experiments on the existence of biogenic processes in situ on waste dumps from exploitation containing residual sulphides are also presented. The processes result in acid mine drainage water generation. These waters are strongly mineralised (over 48 g/L) and of low pH; that is why they are very caustic. The arsenic content (2.558 mg/L) in outflowing waters from old mines is high and over the limits set by the law.

2

Arbutin production via biotransformation of hydroquinone in in vitro cultures of Aronia melanocarpa (Michx.) Elliott

100%

Kwiecień I., Szopa A., Madej K., Ekiert H.

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2013

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vol. 60

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issue 4

865-870

EN

Arbutin (hydroquinone β-D-glucoside) is a compound of plant origin possessing valuable therapeutic (urinary tract disinfection) and cosmetic (skin whitening) properties, which can be obtained from in vitro cultures of plants belonging to different taxa via biotransformation of exogenously supplemented hydroquinone. Agitating cultures of Aronia melanocarpa were maintained on the Murashige and Skoog medium containing growth regulators: the cytokinin - BAP (6-benzylaminopurine), 2 mg/l and the auxin NAA (α-naphthaleneacetic acid), 2 mg/l. The biomass was cultured for 2 weeks and then hydroquinone was supplemented at the following doses: 96, 144, 192, 288 and 384 mg/l either undivided or divided into two or three portions added at 24-hour intervals. The content of the reaction product - arbutin, was determined using an HPLC method in methanolic extracts from biomass and lyophilized medium samples collected 24 hours after the addition of the last precursor dose. The total amounts of arbutin were very diverse, from 2.71 to 8.27 g/100g d.w. The production of arbutin rose with increasing hydroquinone concentration. The maximum content of the product was observed after hydroquinone addition at 384 mg/l divided into two portions. Biotransformation efficiency also varied widely, ranging from 37.04% do 73.80%. The identity of the product - arbutin, after its isolation and purification was confirmed by spectral analysis (1H-NMR spectrum). The maximum amount of arbutin obtained was higher than that required by the latest 9th Edition of the Polish Pharmacopoeia and by the newest 8th Edithion of European Pharmacopoeia for Uvae ursi folium (7.0 g/100g d.w.), and is interesting from practical point of view.

3

Production of triterpenoids with cell and tissue cultures

100%

Malinowska M., Sikora E., Ogonowski J.

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2013

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vol. 60

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issue 4

731-735

EN

Triterpenes are group of biologically active compounds which can be found in higher plants. Their main source are plants bark, leaves, twigs, fruits, resins or oils. The biological activity of triterpens is very diversified and many studies have already confirmed the following therapeutic effects: anti-inflammatory, antimicrobial, antiviral, antifungial, immunomodulatory, and hepatoprotective. Synthesis of triterpenes derivates can be performed by chemical or enzymatic reactions, however biotransformation is more specific and eliminates the side products and the molecule alterations. These processes use isolated enzymes or microorganisms. Cell culture in vitro eliminates problems like extract variability as well as instability of the compounds being obtained during the extraction process. What is more, it ensures high reproducibility and optimal regio- and enantioselectivity. The most widely used technique is a classical screening of a series of microbial strains. Studies on triterpene biotransformation give a lot of information about new biologically active compounds and let predict the metabolism of biological compounds. This review presents most important advancements in the metabolic engineering of microorganisms for the production of triterpenoids. Moreover, the review highlights general strategies to obtain rich biochemical diversity of plants by employing the biocatalysts produced by microorganisms or tissue cultures.

4

New method for the study of Amaryllidaceae alkaloid biosynthesis using biotransformation of deuterium-labeled precursor in tissue cultures

100%

El Tahchy A., Boisbrun M., Ptak A., Dupire F., Chrétien F., Henry M., Chapleur Y., Laurain-Mattar D.

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2010

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vol. 57

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issue 1

75-82

EN

Biotransformation of deuterated-4'-O-methylnorbelladine into alkaloids galanthamine and lycorine in tissue cultures of Leucojum aestivum was demonstrated using HPLC coupled to mass spectrometry. GC-MS screening was also carried to investigate other native and deuterated alkaloids. A total of six labeled alkaloids were identified indicating that 4'-O-methyl-d3-norbelladine is incorporated into three different groups of Amaryllidaceae alkaloids that are biosynthesized by three modes of intramolecular oxidative phenol coupling.

5

Identification of selected microorganisms from activated sludge capable of benzothiazole and benzotriazole transformation

100%

Kowalska K., Felis E.

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2015

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vol. 62

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issue 4

935-939

EN

Benzothiazole (BT) and benzotriazole (BTA) are present in the environment - especially in urban and industrial areas, usually as anthropogenic micropollutants. BT and BTA have been found in the municipal and industrial wastewater, rivers, soil, groundwater, sediments and sludge. The origins of those substances' presence in the environment are various industry branches (food, chemical, metallurgical, electrical), households and surface runoff from industrial areas. Increasingly strict regulations on water quality and the fact that the discussed compounds are poorly biodegradable, make them a serious problem in the environment. Considering this, it is important to look for environmentally friendly and socially acceptable ways to remove BT and BTA. The aim of this study was to identify microorganisms capable of BT and BTA transformation or/and degradation in aquatic environment. Selected microorganisms were isolated from activated sludge. The identification of microorganisms capable of BT and BTA removal was possible using molecular biology techniques (PCR, DNA sequencing). Among isolated microorganisms of activated sludge are bacteria potentially capable of BT and BTA biotransformation and/or removal. The most common bacteria capable of BT and BTA transformation were Rhodococcus sp., Enterobacter sp., Arthrobacter sp. They can grow in a medium with BT and BTA as the only carbon source. Microorganisms previously adapted to the presence of the studied substances at a concentration of 10 mg/l, showed a greater rate of growth of colonies on media than microorganisms unconditioned to the presence of such compounds. Results of the biodegradation test suggest that BT was degraded to a greater extent than BTA, 98-100% and 11-19%, respectively.

6

TYROSOL GLUCOSYLTRANSFERASE ACTIVITY AND SALIDROSIDE PRODUCTION IN NATURAL AND TRANSFORMED ROOT CULTURES OF RHODIOLA KIRILOWII (REGEL) REGEL ET MAXIMOWICZ

86%

Grech-Baran M., Sykłowska-Baranek K., Giebułtowicz J., Wroczyński P., Pietrosiuk A.

Acta Biologica Cracoviensia s. Botanica

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2013

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vol. 55

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issue 2

7

Microbial transformation of citral by Penicillium sp.

86%

Esmaeili A., Tavassoli A.

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2010

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vol. 57

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issue 3

265-268

EN

Thymol is present in the essential oils from herbs and spices, such as thyme. It is produced by these plant species as a chemical defense against phytopathogenic microorganisms. Therefore, this compound has attracted great attention in food industry, i.e., it has been used as a natural preservative in foods such as cheese to prevent fungal growth. Previous studies concerning the biotransformation of nerol by Penicillium sp. and microbial transformation of citral by sporulated surface cultures method (SSCM) of Penicillium digitatum have been reported. The objective of this research was to study the pathway involved during biotransformation of citral by Penicillium sp. using two methods. The culture preparation was done using different microbial methods and incubation periods to obtain Penicillium for citral biotransformation. The biotransformation products were identified by gas chromatography (GC) and gas chromatography/mass spectroscopy (GC/MS). A comparison of the two methods showed that SSCM was more effective, its major products were thymol (21.5%), geranial (18.6%) and nerol (13.7%). LM produced only one compound - thymol - with a low efficiency.

8

Monooksygenazy zależne od cytochromu P-450 oraz enzymy II fazy przemian ksenobiotykow w łożysku

72%

Włoch S.

Annales Academiae Medicae Silesiensis

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2009

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vol. 63

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issue 2

78-84

EN

The fi rst part of this paper contains the discussion of the organization of the basic P-450 cytochrome-dependent monooxygenases including the functional diff erences resulting from their location in the microsomal and mitochondrial fractions, the basic stages of the pertinent metabolic changes, and also, the mechanisms of induction of the Cyp.-450 in the families 1,2,3 and 4. In the next part, the current state of knowledge on monooxygenases in the placental cells has been presented. Attention has been drawn to the fact that despite the low contents of both mRNA and CYP-450 protein in the families 1,2,3 and 4 in syncytiotrophoblast cells at the level of just several percent hepatocytes, this system may perform an important role in the release of indirect toxic metabolites , thus posing threat to the lives of either the embryo or the fetus, particularly in the fi rst trimester of pregnancy. These risks substantially increase in situations where the pregnant woman has had contact with medicines, alcohol, narcotics or tobacco smoke, which are found to be eff ective CYP-450 inducers or inhibitors. In the fi nal part, the activity of Phase II xenobiotic metabolism enzymes in the placenta has been discussed, including UDP-gluconylotransferase, 5-glutation transferase, and sulfotransferases.

PL

W części pierwszej omówiono organizację podstawowych ogniw monooksygenaz zależnych od cytochromu P-450, różnice funkcjonalne wynikające z ich posadowienia we frakcji mikrosomalnej i mitochondrialnej komórek, podstawowe etapy realizowanych przemian, a także mechanizmy indukcji rodziny 1,2,3 i 4 CYP.-450. Następnie przedstawiono aktualny stan wiedzy na temat monooksygenaz w komórkach łożyska. Zwrócono uwagę, iż pomimo niskich zawartości mRNA i białka CYP-450 rodziny 1,2 oraz 3 w komórkach syncytiotrofoblastu na poziomie zaledwie kilkuprocentowym hepatocytów, układ ten może spełniać ważną rolę w uwalnianiu toksycznych metabolitów pośrednich, stwarzając zagrożenie dla zdrowia i rozwoju zarodka oraz płodu, zwłaszcza w I trymestrze ciąży. Owe zagrożenia zdecydowanie wzrastają w warunkach kontaktu ciężarnej kobiety z lekami, dymem papierosowym, alkoholem, narkotykami, które są efektywnymi induktorami lub inhibitorami CYP-450. Omówiono także aktywność w łożysku enzymów II fazy przemian ksenobiotyków, w tym: UDP-glukonylotransferazy, transferazy S-glutationowej i sufotransferaz.

Refine search results

Biogenic catalysis in sulphide minerals' weathering processes and acid mine drainage genesis

Arbutin production via biotransformation of hydroquinone in in vitro cultures of Aronia melanocarpa (Michx.) Elliott

Production of triterpenoids with cell and tissue cultures

New method for the study of Amaryllidaceae alkaloid biosynthesis using biotransformation of deuterium-labeled precursor in tissue cultures

Identification of selected microorganisms from activated sludge capable of benzothiazole and benzotriazole transformation

TYROSOL GLUCOSYLTRANSFERASE ACTIVITY AND SALIDROSIDE PRODUCTION IN NATURAL AND TRANSFORMED ROOT CULTURES OF RHODIOLA KIRILOWII (REGEL) REGEL ET MAXIMOWICZ

Microbial transformation of citral by Penicillium sp.

Monooksygenazy zależne od cytochromu P-450 oraz enzymy II fazy przemian ksenobiotykow w łożysku