ABSTRACTS 2018 #2                                  
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Maissa BOURAHLA, Réda DJEBBAR, Yahia KACI, Ouzna ABROUS-BELBACHIR

Abstract. Plant Growth Promoting Rhizobacteria (PGPR) can play important role in agriculture. The objective of this study was to assess the ability of the isolated strain Pseudomonas putida to improve physiological and biochemical parameters of durum wheat seedlings (Triticum durum Desf. Var. Mohamed Ben Bachir) and helped them to withstand bleaching herbicide the norflurazon. At 10-4 M, the norflurazon induced the bleaching of seedlings (photobleaching). At the physiological level, it caused the inhibition of carotenoids (0.03±0.01 mg g-1), chlorophylls (0.15±0.03 mg g-1 ) and carbohydrates (0.28±0.07 mg g-1) contents. At the cellular level, carotenoids defiency angendred by the norflurazon induced oxidative stress which manifested by an increase of MDA content (32.33±2.08 mmoles g-1), a lipid peroxidation marker, as well as a sharp increase in the electrolytes leakage (63.7±6.01 %) sign of membrane systems deterioration. The norflurazon also decreased the catalase (7.13 µmol H2O2 mn-1mg -1of proteins) and glutathion S-transferase (2 nanomol min-1mg-1 of proteins) activities in the leaves of durum wheat seedlings. The strain of Pseudomonas putida with inherent phosphate solubilizing activity, auxins (IAA) synthesis and EPS production was inoculated to the wheat seedlings in the presence and absence of norflurazon. It had eased phytotoxic effects of norflurazon on wheat seedlings and improving theirs physiology and their antioxidant mechanisms. The bacteria strain used would so represent a valuable partner in the future agriculture by its bioprotective and biostimulating properties.

Keywords: Pseudomonas putida; PGPR (Plant Growth Promoting Rhizobacteria); norflurazon; oxidative stress; Triticum durum.



Lynda MESSAOUDENE, Miguel Palma LOVILLO, Mohammed HAZZIT, Réda DJEBBAR

Abstract. Artichoke (Cynara scolymus L.) is well known for its various health benefits, most of which are related to the phenolic composition. The present study concerns the optimization of phenolic compounds extraction conditions from edible part of artichoke (Cynara scolymus L.), the assessment of antioxidant activity and the comparison of two methods for total phenolic content quantification by sperctrophotometry, Folin Ciocalteu and UV methods. The investigated parameters included methanol concentration, solvent to solid ratio and extraction time. It was found that methanol concentration and solvent to solid ratio are the most significant factor that influences the TPC. The optimal extraction conditions were found to be: 24 hours extraction time, 10 ml for solvent volume and 100 % for methanol concentration. The second variable, the DPPH scavenging capacity was strongly affected by all the studied factors. The best experimental conditions are different from those of TPC. They were found to be 1 hour extraction time, 10 ml for solvent volume and 80 % for methanol concentration. The experimental results obtained revealed a poor correlation between TPC and DPPH scavenging capacity. The last studied response is the TPC based on UV method to TPC based on FC method ratio. We had recorded a significant effect of extraction time and methanol concentration; we had recorded also a positive and significant correlation between the phenolics content determined by using the two different analytical methods. The results suggest that the UV method can be employed as an efficient and fast tool for the determination of total phenolic compounds in artichoke samples.

Keywords: Cynara scolymus L.; antioxidant activity; phenolic compounds; Folin-Ciocalteu; UV method.




Svetlana BOORTSEVA, Maxim BYRSA, Yulia BEREZIUK, Oleg CHISELITSA, Natalia CHISELITSA, Vladimir SHEPTITSKII, Anastasia VASILCHUK, Alexandru MANCIU, Nicolai STARCHUK

Abstract. Importance of lipids in nature can not be underestimated. It is not only a group of substances which participate in process of metabolism; these substances can be wide using in fields of science and industry. Due to increase cost of animal and vegetal lipids, an alternative can serve microbial lipids. Actinobacteria is the group of microorganisms which is an excellent source of lipids, especially strains of genus Streptomyces. In next research changes of fractional composition of lipids of Streptomyces spp. cultivated on complex media with different nutrients were studied. Streptomyces spp. were isolated from soil samples of Republic of Moldova, cultivation was realized on complex media M-I and R. Maximal quantity of lipids in biomass were obtained after cultivation of strains on medium M-I (12.1-14.3%) and on medium R (12.27-18.69%). The most important fraction as sterols achieved following results: after cultivation on medium M-I it varied between 8.3-14.6% and on medium R – 8.7-10.98%. For fraction of phospholipids were fixed next data: after cultivation on medium M-I, the quantity was 9.1-14.3% and on medium R – 8.7-17.16%. Obtained results show perspective of application of bioproducts based on streptomycetes lipids in agriculture and husbandry due to sufficient quantity of total lipids and some fractions apart.

Keywords: streptomycetes; lipids; fractional composition; medium; nutrients; phospholipids; sterols.



Alexei REMIZOVSCHI, Rahela CARPA, Mihail DRĂGAN-BULARDA

Abstract. Mud volcanoes represent related formations, which have structural and functional similarities and can be found on land and in undersea zones. Mud volcanoes are different from other geological forms by their capacity to expell different forms of materia (gas, water and sediment) and the relatively violent kind of performing it. The sizes of mud volcanoes go from very small up to kilometers, shapes go from caldera to cones and they can exhibit from almost inaction to rising columns of fire. The mud consistency also differ, from aqueous to high viscosity, and the emissions can involve high quantities of methane and carbon dioxide. Volcanoes releasing thermogenic methane have the reservoirs at profound depths, while the ones with biogenic gas have the reservoirs no deeper than 2000 m. This review provides informations regarding genesis and distribution of mud volcanoes, and also the description of morphology and topology of the mud volcano and the adjacent area. The classification types are set out, as well as the phenomenon of mud volcanism. In the end the expelled products are identified, different post-genetic processes being established, thus it can be assessed if the expelled products are of thermogenic or biogenic nature. Microbiological processes within mud volcanoes were also described from anaerobic oxidations, aerobic oxidations to methanogenesis. Both, Archaea and Bacteria are involved in these prcesses. Common patterns were identified for mud volcanoes which harbour a large array of bacterial and archaeal phyla. Mud volcanoes have a consistent share in the natural gass emissions into the atmosphere. They have a global occurance and give us a different way to investigate the Earth’s interior, yet are largely unresearched.

Keywords: mud volcano, volcanoes eruption, thermogenic methane, biogenic methane.




Atef CHOUIKH, Fatma ALIA, Souad NEFFAR, Abdelkrim REBIAI, El Hadda ADJAL, Azzedine CHEFROUR

Abstract. To evaluate the natural products in the desert plants, antioxidant activity and phenolic contents of Genista saharae (Fabaceae) growing in Oued Souf region (Algerian desert) were determined during different phases of its development. The results of the yield of methanolic extracts showed that the highest value was recorded in the extracts of the floral phase (8.6%) and the lowest was in the extracts of the fruiting phase (5.16 %). As we observed the relationship in the quantitative content of polyphenols and flavonoids, were recorded with the highest value of polyphenols at the first vegetative phase estimated as 1.33±0.018mg EAG/g Ex and 0.772 ±0.088mg EQu/g Ex, and the lowest value was in fruiting phase 0.443±0.078mg EAG/g Ex and 0.21±0.036mg EQu/g Ex. While the results of antioxidant activity in the free radical revealed that, the extract of the second vegetative phase exceeded with a best inertial capacity than the other extracts (IC50= 0.247 mg/ml). As for concerning the hemolysis test, the finding indicated at distinction of extract the first vegetative phase with a lower hemolysis 31.26%. Using the HPLC, the qualitative analysis of extracts showed quantitative and qualitative differences concerning the presence of some phenolic compound such as: Gallic acid, Caffeic acid, ρ-Coumaric acid, Vanillin and Rutin in four extracts. According to results obtained it seemed that there is a disparity in the phenolic content in terms of the different stages of growth. This seemed obvious in antioxidant activity results that can be the change in the quality and concentration of the phenolic compounds between different stages of growth.

Keywords: Genista saharae; Polyphenols; Flavonoids; Antioxidant activity; test DPPH; Hemolysis test; HPLC.




Olga POSTOLACHI, Inna RASTIMESINA, Tatiana GUTUL

Abstract. Among actinomycetes the genus Streptomyces is the most widely studied and well known. Ecologically, streptomycetes, due to their extracellular enzymes, have a great potential for biodegradation of organic and inorganic toxic compounds. Among metal-based engineered nanomaterials, iron nanoparticles (NPs) are, probably, the most used for bioremediation of a broad spectrum of pollutants. Iron-based NPs are expected to be non-toxic, due to the use of Fe atom in several pathways of cell metabolism and, therefore, low iron toxicity. The present study aims to determine the effect of magnetite NPs, zero-valent iron NPs and fluorinated dinitroaniline herbicide trifluralin on growth of streptomycetes strains. Streptomycetes strains were isolated from soil long-term polluted with obsolete pesticides, DDT and trifluralin. The inhibition activity of iron NPs and trifluralin was evaluated using express-method. Each streptomycete strain had an individual reaction to the solutions of iron NPs. Most of the studied microorganisms were found to be sensitive to trifluralin, except Streptomyces sp. 0112 and Streptomyces sp. 0212. Cytotoxic effect of trifluralin was diminished by iron NPs, but not fully reduced. Fe(0) NPs produced no inhibitory effect on growth of streptomycetes. The obtained data has revealed the prospect of developing a procedure for bioremediation of soils polluted with trifluralin, using the phenomenon of synergism between iron NPs and streptomycetes.

Keywords: streptomycetes; iron nanoparticles; trifluralin; growth inhibition



Katia AMI, Reda DJEBBAR, Majda KHELIFI-SLAOUI, Ouzna ABROUS-BELBACHIR

Abstract. This experiment was conducted to determine the effect of exogenous proline (20 mM) on the physiological and biochemical behavior of durum wheat seedlings subjected to a salt constraint (10 g/l NaCl). This effect was evaluated through the estimation of plant water status (leaf relative water content), photosynthetic pigments, sugars content, water soluble proteins content, the osmotic adjustment (endogenous proline and glycine betaine), the lipid peroxidation (the membrane integrity and the malondialdehyde content) and the activity of the antioxydant enzyme catalase in wheat plantlets. Results obtained show that the saline stress affects the majority of the studied parameters. However, exogenous application of proline seems to attenuate the negative effects of the saline stress by the improvement of the content of total chlorophyll, proteins, glycine betaïne and the relative electrolyte leakage. These results suggest the capacity of the exogenous application of proline to improve the tolerance of the saltstressed wheat plants.

Keywords: exogenous proline, salt stress, Triticum durum, osmolyte, antioxidant.




Valentina BULIMAGA, Liliana ZOSIM, Daniela ELENCIUC, Aurelia CRIVOI, Iurii BACALOV

Abstract. A study of the [Cr(Gly)3]Cl effect on the biochemical composition of the cyanobacterium Spirulina (Arthrospira) platensis has been carried out at cultivation depending on the lighting regime and the timing of addition of this compound. Its positive effect on protein content (including peptides) was established within the concentration limits of up to 30 mg /l. Chromium accumulation was more efficient in light/dark photoperiod (14/10 hours) in case of supplementation on the 1st and 3rd days in the portions. The technological scheme for obtaining chromium bioadditive was proposed. This procedure is based on using a Cr(III) glicinate as source of Cr(III) for obtaining of spirulina biomass enriched with chromium (0,75%) and valuable bioactive substances.

Keywords: Cyanobacteria cultivation; Spirulina platensis; chromium; food bioadditive; insulin activity



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