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Research Group 5 - RG5 - Miroslav Vrvić


Research description:

Development and production of new dietetic products based on natural resources.

Substances that stimulate the development of “good” microbes or such microorganisms that in the gut are prebiotics and probiotics, i.e. symbiotics. By birth and by breast-feeding (“prebiotic”), the new born establishes an ideal microflora of the digestive system (“probiotics”), which is a precondition for a successful and healthy beginning of the child’s life. Changing the type of food we eat and due to all other influences during one’s growth, development, becoming of age and aging, the composition of the microflora in the gastrointestinal tract is also changed and its predominantly mild medicinal effects become the very opposite! These are the reasons of the real “hunting” of new prebiotics and probiotics which complex of scientific confirmed favourable effects on the health.

Bifidobacterium breve Development and production of the infant formulae and the follow-on-formulae, which arises from this need is one of our main goals. Functionally new Infant Formulae and Formulae for pregnant women will be developed and tested up to the industrial level, based on fresh cow milk from protected areas, that will have special features in relation to bifidogenic effect, thanks to their own prebiotics and probiotics (symbiotics) and antioxidation features. The expected high antioxidative potential (that will be tested spectrophotometrically, electrochemically and by electron paramagnetic resonance - EPR) of these products will be implemented by the application of microbial polysaccharide nanoparticles (from our species of Aureobasidium and yeast glucans and pullulans) as a biomaterial with its own species of encapsulated bifidobacteria. The confirmation of effects of these nutritionally new features will be tested in vitro and in clinical nondynamic studies. Polysaccharides of mother's milk will be individually tested as unsurpassable prebiotics.

(1→3)-β-D-glucan – Chemical structure Β-D-glucans are nondigestible polysaccharides widely found in nature in such sources as cereal grains, including oats and barley, as well as in yeast, bacteria, algae and mushrooms. Β-D-glucans are primarly located in the cell walls. Yeast Β-D-glucans is a polysaccharide derived from the cell walls of baker’s yeast (Saccharomyces cerevisiae).  We plan to investigate the effects of baker’s yeast (Saccharomyces cerevisiae) (1→3)-β-D-glucan extracts showing different levels of purity, on the proliferation of bifidobacteria under in vitro conditions and antiradical activity of this glucan (iii) and its digestibility. The aim is to evaluate prebiotic effects and to examine possible mechanisms of (1→3)-β-D-glucan activity.

Pullulan is one of the extracellular polysaccharides produced by Aureobasidium pullulans. This homopolymer is a linear glucan which consists of maltotriosyl repeating units connected by (1→6)-a-D-linkages. It is biodegradable, nontoxic, non-immunogenic and readily soluble in water. Reason for the great application of this microbial polysaccharide lies in excellent physical and chemical properties of polymers that make it suitable in many industries such as food industry, pharmaceutical, medicine, biotechnology, electronic etc. Due to adhesive properties, it can be used to form fibers, compression moldings, and strong, oxygen-impermeable edible films. One of the common chemical modifications of pullulan is introducing aldehyde groups into the linear chain of this glucan. These reactive groups can be further chemical bond to many compounds that posses amino function, which already has commercial application in medicine, pharmaceutical industry, biomedicine etc.

Our strategy for development mineral supplements in food relates to the conventional biotechnologies for obtaining biomass (complex bioligands-“biological agents”) enriched by organically bonded essential oligo and trace elements (EOTEs) among which are: selenium, chromium (III), calcium, magnesium, iron (II), zinc, potassium and silicon. Based on natural organic complex ligands (baker’s and brewing yeast and bacteria) several products (selenium, chromium and calcium) of these our own biotechnologies are marketed as food supplements and non-prescription drugs only for oral application at present.

Modification of proteins- identification of reaction products and possibilities for their determination and application in clinical and toxicological practice.

Advanced glycation end products (AGEs) are formed in the reaction of carbonyl-containing materials with N-terminal and Lys side-chain amino groups, the guanidine group of Arg, sulfhydryl group of Cys on proteins, and through a series of reactions and rearrangement. The contibution of altered carbohydrate metabolism and nutritients in formation of AGEs is considered. Molecules modified with α-oxoaldehyde can affect cellular functionality via gene expression, lead to micro- and macro-vascular complications in diabetes, contribute to upregulation of inflammatory and tissue-injury-provoking molecules (interaction of AGEs and receptor RAGE), protein cross-linking and apoptosis.

The role of thiol group in protein modification with α-oxoaldehyde as well as in cross-linking via reactive compounds has not been sufficiently investigated. New studies have shown that its microenvironment influences this reaction. Some of the final products of these reactions are not well-characterized as well as the consequences that may occur due to changes in structure and function of proteins. Also, the possibilities for their usage as markers of pathological states and how to prevent modification should be consider.

Diazinon, malathion, chlorpyrifos, azinphos-methyl and phorate have been commonly used organophosphate pesticides (OPs) to control a variety of insects in agriculture and household environment. These compounds are essentially nerve poisons, highly toxic to animals and humans. OPs inhibit AChE, induce oxidative stress in animals and humans, generate free radicals and cause lipid peroxidation leading to genetic material damage and cell malformations. The development of means for improving the sensitivity of biosensor for determination of OPs in food and other materials is important.


Research skills and methods applied by the group:
Group members and ongoing projects:

Prof dr Ljuba Mandić, senior researcher
Project: Investigation of structure and function of biological important macromolecules in physiological and pathological states

MSc Mila Ilić, PhD student
Project: Biomass and metabolism of microorganisms as a source of widely usable products and biochemical reactions; financed by Ministry of Science and Technological Development, Serbia

Nikoleta Lugonja, PhD student
Project: Biomass and metabolism of microorganisms as a source of widely usable products and biochemical reactions; financed by Ministry of Science and Technological Development, Serbia

MSc Olga Martinov, PhD student
Project: Biomass and metabolism of microorganisms as a source of widely usable products and biochemical reactions; financed by Ministry of Science and Technological Development, Serbia

MSc Vladimir Beskoski, PhD student
Project: Biomass and metabolism of microorganisms as a source of widely usable products and biochemical reactions; financed by Ministry of Science and Technological Development, Serbia

MSc Srđan Miletić, PhD student
Project: Biomass and metabolism of microorganisms as a source of widely usable products and biochemical reactions; financed by Ministry of Science and Technological Development, Serbia

MSc Vesna Jovanović, PhD student
Project:Investigation of structure and function of biological important macromolecules in physiological and pathological states; financed by Ministry of Science and Technological Development, Serbia

MSc Jelena Aćimović, PhD student
Project: Investigation of structure and function of biological important macromolecules in physiological and pathological states; financed by Ministry of Science and Technological Development, Serbia

MS Jelena Milić, PhD student
Project: Biomass and metabolism of microorganisms as a source of widely usable products and biochemical reactions; financed by Ministry of Science and Technological Development, Serbia

Jovana Stefanović, PhD student
Project: Biomass and metabolism of microorganisms as a source of widely usable products and biochemical reactions; financed by Ministry of Science and Technological Development, Serbia

Milena Rikalović, PhD student
Project: Biomass and metabolism of microorganisms as a source of widely usable products and biochemical reactions; financed by Ministry of Science and Technological Development, Serbia

Tamara Lazarević-Pasti, PhD student
Project: Research of mechanisms of interaction of biologically active compounds with biomolecules; financed by Ministry of Science and Technological Development, Serbia


Collaborations
Selected recent publications:
  1. Izrael-Zivkovic L.T., Gojgic-Cvijovic G.Dj., Gopcevic K.R., Vrvic M.M., Karadzic I.M., Enzymatic characterization of 30 kDa lipase from Pseudomonas aeruginosa ATCC 27853, J. Basic Microb. 49 (2009) 452-462.
  2. Bosnić O.M., Gopcevic K.R., Vrvić M.M., Karadžić I.M., Inhibition of trypsin by heparin and dalteparin, a low molecular weight heparin, J. Serb. Chem. Soc. 74 (2009) 379-388.
  3. Marković J.P., Radović J.B., Štrbanović R.T., Bajić D.S., Vrvić M.M., Changes in the infrared attenuated total reflectance (ATR) spectra of lignins from alfaalfa steam with growth and development, J. Serb. Chem. Soc. 74 (2009) 885-892.
  4. Arsić B., Prekajski N., Vučić V., Tepšić J., Popović T., Vrvić M., Glibetić M., Milk in human nutrition: Comparison of fatty acid profiles, Acta Vet.-Beograd, 59 (2009) 569-578.
  5. Takic M.,  Ristic-Medic D. K.,  Mandic Lj. M.,  Glibetic M.,  Arsic A.,  Debeljak-Martacic J.,  Ristic-Oddiano G. ,N-3 polyunsaturated acids in erythrocyte phospholipids are associated with insulin sensitivity in obese patients on a typical Serbian diet. Archives of biological sciences, 61 (2009) 37-43.
  6. Aćimović J., Stanimirović B., Mandić Lj.: The role of thiol group in protein modification with methylglyoxal. Journal of Serbian Chemical Society, 74 (2009) 867-883.
  7. Acimović J. M., Stanimirović B. D., Todorović N., Jovanović V. B., Mandić Lj. M., Influence of the microenvironment of thiol groups in low molecular mass thiols and serum albumin on the reaction with methylglyoxal, Chemico-Biological Interactions, 188 (2010) 21-30.
  8. Vitorovic-Todorovic, M. D., Juranic, I. O. Mandic, Lj. Drakulic, B. J., 4-Aryl-4-oxo-N-phenyl-2-aminylbutyramides as acetyl- and butyrylcholinesterase inhibitors. Preparation, anticholinesterase activity, docking study, and 3D structure-activity relationship based on molecular interaction fields. Bioorganic & Medicinal Chemistry 18 (2010) 1181-1193.
  9. Filipović D., Mandić Lj., Kanazir D., Pajović S., Acute and/or chronic stress models modulate CuZnSOD and MnSOD protein expression in rat liver, Molecular and Cellular Biochemistry, 338 (2010) 167–174.
  10. Lazarević-Pašti T., T.Momić, Onjia A., Vujisić Lj., Vasić V., Myeloperoxidase-mediated oxidation of organophosphorus pesticides as a pre-step in their determination by AchE based bioanalytical methods, Microchimica Acta, Volume 170 (2010) 289.
  11. Lugonja N.M., Martinov O.B., Rasovic M., Spasic S.D., Gojgic G.Dj., Vrvic M.M., A Comparative Investigation of an In Vitro and Clinical Test of the Bifidogenic Effect of an Infant Formula, J. Clin. Biochem. Nutr., In press.
  12. Pesic M., Barac M., Vrvic M., Ristic N., Macej O., Stanojevic S., Qualitative and quantitative analysis of bovine milk adulteration in caprine and ovine milks using native-PAGE, Food Chem., In press.
  13. Martinov O.B., Spasic S.D., Lugonja N.M., Gojgic-Cvijovic G.Dj., Vrvic M.M., Infant formula as a substrate for bifidogenesis: an in vitro investigation, Afr. J. Biotechnol., In press.
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