Emanuel Vamanu
University of Agronomic Sciences and Veterinary Medicine of Bucharest
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Featured researches published by Emanuel Vamanu.
BioMed Research International | 2013
Emanuel Vamanu; Sultana Nita
Boletus edulis is a wild edible mushroom habitually consumed by rural populations. Ethanolic and methanolic extracts was obtained in cold and hot water from dried fruit bodies. The antioxidant activity of freeze-dried extracts from B. edulis were investigated using free radicals scavenging activity, reducing power, metal chelating effect, inhibition of lipid peroxidation, and the identification of antioxidant compounds. The levels of different compounds with antioxidant properties were higher in alcoholic extracts compared with aqueous extracts. Rosmarinic acid was the major phenolic compound, it being identified in a concentration between 7 ± 0.23 and 56 ± 0.15 mg/100 g extract. A positive correlation between the content of total phenols, flavonoids, anthocyanins, and tocopherols, and the antioxidant capacity of the extracts was determined. The results showed that the ethanolic extract of Romanian wild mushroom B. edulis represents a natural source of functional compounds.
BioMed Research International | 2012
Emanuel Vamanu
Exopolysaccharides (EPS) and internal (intracellular) polysaccharides (IPS) obtained from the Pleurotus ostreatus M2191 and PBS281009 cultivated using the batch system revealed an average of between 0.1–2 (EPS) and 0.07–1.5 g/L/day (IPS). The carbohydrate analysis revealed that the polysaccharides comprised 87–89% EPS and 68–74% IPS. The investigation of antioxidant activity in vitro revealed a good antioxidant potential, particularly for the IPS and EPS isolated from PBS281009, as proved by the EC50 value for DPPH, ABTS scavenging activity, reducing power, and iron chelating activity.
Molecules | 2012
Emanuel Vamanu
The antioxidant and antimicrobial potential of the ethanolic extract of Pleurotus ostreatus PQMZ91109 mycelium was determined based on inorganic and organic nitrogen sources in the culture medium. The presence of ammonium sulfate resulted in a greater accumulation of bioactive compounds compared with the organic ones. This finding was also confirmed by the low values of the ascertained EC50 and minimum inhibitory concentration (MICs). Among the organic sources, peptone followed by corn extract, led to a more important radical-scavenging activity. The extracts selectively inhibited the tested strains, mainly the two of the genus Candida, at an MIC value of 1.25 mg/mL. The antioxidant potential was evaluated by the inhibition capacity of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, β-carotene-linoleic acid, which is the reducing power. In addition, the quantity of the compounds with antioxidant effects confirmed the data obtained, they being present in the extracts.
African Journal of Biotechnology | 2007
Ovidiu Popa; Narcisa Babeanu; Adrian Vamanu; Emanuel Vamanu
A mutant strain of the yeast Saccharomyces cerevisiae growing on ethanol as single source of carbon and energy was used in optimization experiments at laboratory and micropilot scale, following the surface response methodology. The cultivation medium optimization was performed on the basis of maximization of dry cell weight and the process parameters optimization on the basis of substrate yield maximization.
Natural Product Research | 2013
Emanuel Vamanu
The antioxidant activity of the exopolysaccharides (EPS) and intracellular polysaccharides (IPS) obtained from the mycelia obtained by submerged culture of two edible Pleurotus ostreatus strains, PQMZ91109 and PSI101109 in a batch bioreactor was determined. EPS and IPS showed significant antioxidant activities (in vitro) especially in the scavenging effect on the DPPH and ABTS radicals, reducing power and chelating effect on ferrous ions. The tests proved the differences between the two mushrooms, concerning the biological activity of polysaccharides. The data sustain that P. ostreatus polysaccharides are natural antioxidant for pharmaceutical and food industries, particularly PSI101109.
Annals of Microbiology | 2013
Emanuel Vamanu; Diana Pelinescu; Ionela Avram; Sultana Niță; Adrian Vamanu
The modulation potential of the PROBAC product on the simulated microbiota of an infant colon was determined by using the GIS1 single-chamber system of simulation of the human colon. The determination of the viability of each group of microorganisms and of the metabolic activity was performed for each simulated compartment. In order to confirm the biochemical tests, at least one colony from each sample was analyzed from a genetic point of view, using the repetitive-element PCR fingerprinting (rep-PCR) technique. Molecular analysis demonstrated the persistence of the two strains representing the basis of the PROBAC product, and the genetic stability of the lactic acid bacteria strains included in the final product after transiting the various parts of the simulated colon. After analyzing the viability of lactic acid, bacteria strains that were introduced in the final product in the presence and absence of the prebiotic while transiting the sections of the colon, produced an increase in lactic and bifidobacteria number, especially in the transverse and descending sections. In vitro approaches to study the human colon microbiota, and intestinal microbial processes offer an excellent experimental set-up to study the mechanism of action.
Journal of Medicinal Food | 2013
Emanuel Vamanu
The antioxidant and antimicrobial properties of two edible mushrooms (Pleurotus ostreatus PBS281009 and Coprinus comatus M8102) were evaluated in this study. The mycelium ethanolic extract obtained in the presence of four different nitrogen sources was investigated with regard to their production of phenolic compounds, β-carotene, lycopene, and their antimicrobial and antioxidant properties. Significant differences in phenol and β-carotene concentrations in mycelia grown in different nitrogen sources were observed. Corn extract proved to be the most appropriate source for increasing bioactive properties, leading to the lowest EC₅₀ and minimum inhibitory concentration values in the P. ostreatus PBS281009 species, while peptone was the most suitable for the C. comatus M8102 species. The antimicrobial capacity was screened against Gram-positive and Gram-negative bacteria and against two species of Candida. These results indicate that the mycelia from these two edible mushrooms can be used as nutraceuticals and functional products.
Indian Journal of Microbiology | 2015
Veronica Moroeanu; Emanuel Vamanu; Gabriela Paun; Elena Neagu; Oana Ungureanu; Sandra A. V. Eremia; Gabriel Lucian Radu; Robertina Ionescu; Diana Pelinescu
AbstractThe main goal of our study was to evaluate the effect of the individual administration of five lyophilized lactic acid bacteria strains (Lactobacillus fermentum 428ST, Lactobacillus rhamnosus E4.2, Lactobacillus plantarum FCA3, Lactobacillus sp. 34.1, Weissella paramesenteroides FT1a) against the in vitro simulated microbiota of the human colon using the GIS1 system. The influence on the metabolic activity was also assessed by quantitative determination of proteins and polysaccharides at each segment of human colon. The obtained results indicated that the lactic acid bacteria L. rhamnosus E4.2 and W. paramesenteroides FTa1 had better efficiency in synthesising exopolysaccharides and also a better probiotic potential and therefore could be recommended for use in probiotics products or food industry.
Natural Product Research | 2018
Emanuel Vamanu
Abstract Wild edible mushrooms are considered as a cheap food source, but rich in bioactive compounds, especially in phenolic compounds. The purpose of the study was to determine the antioxidant and antimicrobial activity and the content of polyphenolcarboxylic acids in 10 species of mushrooms commonly used (consumed) in Romania and two controls. The effect against free radicals, lipid peroxidation and reducing power were determined. The antimicrobial effect was revealed on some strains with pathogenic effect by disk diffusion assay. The antioxidant capacity expressed in vitro was correlated both with the presence of the main polyphenolcarboxylic acids, and also with the presence of other bioactive molecules (flavonoids, carotenoid compounds, etc.).
Food Science and Biotechnology | 2012
Emanuel Vamanu; Diana Pelinescu; Irina Marin; Adrian Vamanu
The purpose of this study was to test the viability of the probiotic bacteria product in a unicameral system, gastrointenstinal simulation (GIS1), for in vitro simulation of the conditions in the stomach and small intestine. The product contained a ratio of 1:1 Lactobacillus paracasei YR and Enterococcus faecium VL47 strains, in freeze-dried form and 10 g/L lactulose. The strains’ viability was evaluated under simulated gastric and small intestine conditions, in comparison with Lactobacillus johnsonii La1 strain. The experiment was performed in the presence/absence of lactulose. The strains of L. johnsonii La1 and E. faecium VL47 have shown a better resistance to bile salts and low pH, in comparison with L. paracasei YR. The survival capacity, Cs, was equal to 0 for L. paracasei YR after addition of pancreatic juice and bile salts. Losses for the other 2 strains were about 6 log CFU/mL after transit through the compartments.
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University of Agronomic Sciences and Veterinary Medicine of Bucharest
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