- Natural antimicrobial agents, Plant biotechnology, Microbiology, Antibiotic Resistance, Essential oils, Nanoparticles, and 10 moreBiocontrol of Plant Pathogens, Bio Technology, Molecular Biology, Applied microbiology, Mycology and Plant pathology, Microbiology and Molecular Biology, Ecology, Conservation Biology, Beneficial microorganisms, and Biodiversityedit
The industrial processing of leather has a high environmental impact due to the heavy use of polluting chemicals in the tanning process. Microorganisms can be used in order to degrade natural fibers like fur, leather and cotton because... more
The industrial processing of leather has a high environmental impact due to the heavy use of polluting chemicals in the tanning process. Microorganisms can be used in order to degrade natural fibers like fur, leather and cotton because they synthesized enzymes that can break chemical bonds in these materials. Some proteolytic enzymes, like collagenases, have a number of industrial applications in fur and leather industry and, moreover, are nontoxic and ecofriendly. This paper reports the purification and characterization of a fungal collagenase produced by an Aspergillus strain. Aspergillus oryzae Mi 156 and Aspergillus ochraceus Mi 153 were tested for their capacity to degrade native collagen. Enzymatic activity and protein content were determined using spectrophotometrical methods. The best results regarding collagenolytic activity were obtained for fungal strain Mi 156. The enzyme was separated by ammonium sulphate precipitation and analyzed for its optimum pH and temperature. Th...
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Biodegradation of fibrous protein is a challenge due to the resistance of the raw material. Enzymes based processes are an alternative to conventional chemical ones because they are environmental friendly, but their efficiency is still... more
Biodegradation of fibrous protein is a challenge due to the resistance of the raw material. Enzymes based processes are an alternative to conventional chemical ones because they are environmental friendly, but their efficiency is still limited. They are used mainly in the process of leather obtaining. In the last decade they gain a lot of credit for waste degradation purposes. The main enzymes involved in leather and fur degradation are collagenases and keratinases. The aim of the reported researches is to test a proteolytic complex for its capacity of destroying leather and fur wastes. Four bacterial strains were tested regarding their capacity of hydrolyzing collagen and keratin from bovine leather and sheep fur. For comparison synthetic fur was considered too. Best results were obtained when using sheep leather. The influence of leather dyes was also investigated. Three types of sheep fur were tested: no painted, white painted and black painted. For the painted materials the degr...
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Polyhydroxyalkanoates (PHAs) are polyesters of hydroxyalkanoates synthesized by various bacteria as intracellular carbon and energy storage compounds and accumulated as granules in the cytoplasm of cells. In this work, we describe the... more
Polyhydroxyalkanoates (PHAs) are polyesters of hydroxyalkanoates synthesized by various bacteria as intracellular carbon and energy storage compounds and accumulated as granules in the cytoplasm of cells. In this work, we describe the isolation and characterization of Pseudomans putida P5 strain, as well as of some of its derivatives (mutants and recombinants) regarding the accumulation of PHAs. All the strains were subjected to fermentation and showed PHA accumulation with glucose, gluconate or octanoate as carbon source. In order to obtain PHA produced by these strains, a special procedure was developed, which allowed 80% PHA recovered. Differences in msc-PHA accumulation were observed in chemically induced mutants. RAPD analysis of these mutants proved that some rearrangements are produced as result of mutagenesis. The best results concerning msc-PHA accumulation were obtained when 0.4% octanoate was used. Different other lipid substrates (vegetal oils) were tested in order to es...
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The wooden churches made between 1750 and 1850 have as decorative elements paintings madeon wood or wooden panels. [...]
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There were performed in vitro interactions of five plant lectins purified by affinity chromatography with seven pathogenic bacteria cultivated in liquid media. The positive results were scored by the degree of bacterial cells... more
There were performed in vitro interactions of five plant lectins purified by affinity chromatography with seven pathogenic bacteria cultivated in liquid media. The positive results were scored by the degree of bacterial cells agglutination. There have been noticed strong agglutinations of Salmonella typhymurium and Salmonella gallinarum with the lectins isolated from pumpkin seeds, potato buds and potato tubers. Escherichia coli and Pseudomonas aeruginosa were better agglutinated by vegetable marrow and pumpkin seeds lectins and weaker by potato buds and tubers lectins. Glutaraldehyde immobilization of the lectin isolated from potato buds resulted in an insoluble polymer suspension. The interaction of the lectin polymer suspension with the liquid cultures of Salmonella and Pseudomonas was quantified by measuring the OD (660 nm) at time 0 and after 10 minutes of standing. The decrease of the OD demonstrated that immobilized insoluble lectin polymer bound bacterial cells and the aggre...
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... Cell AdsorptionDesorption. Bacteriocin extraction from the broth was carried out by cell adsorptiondesorption method (Yang et al. 1992) with slight modifications. Prior to extraction, the W. paramesenteroides culture (1 L) was ...
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The interaction of plant with both pathogenic and non-pathogenic microorganisms can trigger active defense reactions in plant. The defence response of Cucumis sativus L. plants treated with beneficial bacteria and phytopathogenic fungi... more
The interaction of plant with both pathogenic and non-pathogenic microorganisms can trigger active
defense reactions in plant. The defence response of Cucumis sativus L. plants treated with beneficial
bacteria and phytopathogenic fungi was evaluated. Cucumber plantlets treated with bacterial isolates
having antifungal activity (Bacillus licheniformis B40, Bacillus amyloliquefaciens Bw, Bacillus sp. Bw1,
Pseudomonas aeruginosa P14) and fungal (Pythium debaryanum Hesse) suspensions were examined for
antioxidant system activation. Potential alteration in superoxide dismutases, catalases, guaiacol
peroxidases and lignin production was approached using biochemical and histochemical methods.
Bacterial inoculation increased the number of superoxide dismutase and catalase isoforms, and also the
enzymatic activity of these antioxidants. Reinforcement of epidermal and cortical cell walls through lignin
deposition was observed using histochemical methods. These results showed that antioxidant enzymes
activity and lignin production were intensified in treated variants, indicating the activation of some
defense mechanisms, and a potential increase of plant resistance to pathogen attack
defense reactions in plant. The defence response of Cucumis sativus L. plants treated with beneficial
bacteria and phytopathogenic fungi was evaluated. Cucumber plantlets treated with bacterial isolates
having antifungal activity (Bacillus licheniformis B40, Bacillus amyloliquefaciens Bw, Bacillus sp. Bw1,
Pseudomonas aeruginosa P14) and fungal (Pythium debaryanum Hesse) suspensions were examined for
antioxidant system activation. Potential alteration in superoxide dismutases, catalases, guaiacol
peroxidases and lignin production was approached using biochemical and histochemical methods.
Bacterial inoculation increased the number of superoxide dismutase and catalase isoforms, and also the
enzymatic activity of these antioxidants. Reinforcement of epidermal and cortical cell walls through lignin
deposition was observed using histochemical methods. These results showed that antioxidant enzymes
activity and lignin production were intensified in treated variants, indicating the activation of some
defense mechanisms, and a potential increase of plant resistance to pathogen attack
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Abstract: Bacillus spp. strains have been identified as producers of different kinds of inhibitory compounds for filamentous fungi. The previous experiments done in the Genetic Engineering Laboratory of the Faculty of Biotechnology,... more
Abstract: Bacillus spp. strains have been identified as producers of different kinds of inhibitory compounds for filamentous fungi. The previous experiments done in the Genetic Engineering Laboratory of the Faculty of Biotechnology, Bucharest, have shown that the ...
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SUMMARY World-wide, fungal growth destroys large amount of vegetables, both pre-and postharvest. Growth of moulds in food leads to reduced nutritional values and production of allergenic spores and hazardous mycotoxins. Thus, there is a... more
SUMMARY World-wide, fungal growth destroys large amount of vegetables, both pre-and postharvest. Growth of moulds in food leads to reduced nutritional values and production of allergenic spores and hazardous mycotoxins. Thus, there is a relatively short list of ...
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Abstract Nineteen bacterial strains, isolated from soils (clean or oil-polluted area) were subjected to a screening programme using Nile red or Nile blue staining to select polyhydroxyalkanoates (PHA)-accumulating strains. At least 6 new... more
Abstract Nineteen bacterial strains, isolated from soils (clean or oil-polluted area) were subjected to a screening programme using Nile red or Nile blue staining to select polyhydroxyalkanoates (PHA)-accumulating strains. At least 6 new isolates presented an ...
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... Daniel Fologea,' Aurelia Brezeanu; Mihai Radu, Petruta Cornea: and Ion Vatafu' Biophysics Department, Lab. ... Kloti, A., Iglesias, VA, Wunn, J., Burkhardt, PK, Datta, SK, and Potrykus, I.: Gene... more
... Daniel Fologea,' Aurelia Brezeanu; Mihai Radu, Petruta Cornea: and Ion Vatafu' Biophysics Department, Lab. ... Kloti, A., Iglesias, VA, Wunn, J., Burkhardt, PK, Datta, SK, and Potrykus, I.: Gene transfer by electroporation into intact scutellum cells of wheat embryos, Plant Cell Rep. ...
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M. ZAMFIR, R. CALLEWAERT, P.C. CORNEA, L. SAVU, I. VATAFU and L. DE VUYST.1999.Lactobacillus acidophilus IBB 801 produces a small bacteriocin, designated acidophilin 801, with an estimated molecular mass of less than 6·5 kDa. It displays... more
M. ZAMFIR, R. CALLEWAERT, P.C. CORNEA, L. SAVU, I. VATAFU and L. DE VUYST.1999.Lactobacillus acidophilus IBB 801 produces a small bacteriocin, designated acidophilin 801, with an estimated molecular mass of less than 6·5 kDa. It displays a narrow inhibitory spectrum (only related lactobacilli but including the Gram-negative pathogenic bacteria Escherichia coli Row and Salmonella panama 1467) with a bactericidal activity. The antimicrobial activity of cell-free culture supernatant fluid was insensitive to catalase but sensitive to proteolytic enzymes such as trypsin, proteinase K and pronase, heat-stable (30 min at 121 °C), and maintained in a wide pH range. The proteinaceous compound was isolated from cell-free culture supernatant fluid and purified. Crude bacteriocin was isolated as a floating pellicle after ammonium sulphate precipitation (40% saturation) and partially purified by extraction/precipitation with chloroform/methanol (2/1, v/v). Further purification to homogeneity was performed by reversed phase Fast Performance Liquid Chromatography. The amino acid composition was determined. Amino acid sequencing revealed that the N-terminal end was blocked.
Research Interests: Engineering, Chemical Engineering, Genetics, Microbiology, Technology, and 48 moreMeat Science, Bacteriology, Mass Spectrometry, Medical Microbiology, Biological Chemistry, Applied microbiology, Multidisciplinary, Animal Production, Biological Sciences, Protein Structure and Function, Food Biochemistry, Microbiology and Biotechnology, Bacteriocins, Lactic Acid Bacteria, Escherichia coli, Listeria monocytogenes, Staphylococcus aureus, Polymerase Chain Reaction, Tunicamycin, Trypsin, Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis, Ion Exchange Chromatography, High Performance Liquid Chromatography, Enzyme, Salmonella, CHEMICAL SCIENCES, Antibacterial activity, Substrate Specificity, Microbial Sensitivity Tests, Food Sciences, Enzyme activity, Amino Acid Profile, Agricultural and Food Chemistry, Molecular weight, Amino Acid Sequence, Base Sequence, Membrane Protein, Salts, Systems Biotechnology Bioprocess and Metabolic Engineering, Hydrogen-Ion Concentration, Kinetic Parameter, Lactococcus lactis, DNA-footprinting, Ammonium Sulfate, Lactobacillus Acidophilus, Pathogenic Bacteria, Biochemistry and cell biology, and Molecular Sequence Data
Lactobacillus acidophilus IBB 801 produces a small bacteriocin, designated acidophilin 801. Studying the relationship between growth and bacteriocin biosynthesis revealed primary metabolite kinetics of bacteriocin production with a peak... more
Lactobacillus acidophilus IBB 801 produces a small bacteriocin, designated acidophilin 801. Studying the relationship between growth and bacteriocin biosynthesis revealed primary metabolite kinetics of bacteriocin production with a peak activity at the end of the exponential growth phase followed by a decrease during the stationary phase. Both microbial growth and bacteriocin production was inhibited by lactic acid. Whereas volumetric bacteriocin production (activity units (AU) ml−1) was favoured under pH-controlled conditions, bacteriocin titres rapidly decreased because of strong adsorption of the bacteriocin molecules to the producing cells under less acidic conditions.