Papers by Florentina Israel Roming
Scientific Bulletin. Series F. Biotechnologies, 2014
The method described in this paper was adapted for determination of provitamin A from meat based ... more The method described in this paper was adapted for determination of provitamin A from meat based products that were supplemented with plant oils contain carotenes. The first step consisted in grease saponification with alcoholic KOH solution and antioxidant, for 30 minutes. Acetone and hexane were used for the extraction of carotenes several times. Finally the absorbance was determined at 450 nm. Quantification was realised with a calibration curve prepared using 5 µg/ml β-carotene solution. The method was tested for determination of β-carotene in three samples of meat products supplemented with sea-buckthorn (Hippophae rhamnoides) oil. For comparison non supplemented meat products was considered too. The provitamin A content ranged between 0.109 and 0,218 mg/100g and after one week between 0.079 and 0.195 mg/100g in the product tested. Different values were obtained according to the preparation technology.
Scientific Bulletin. Series F. Biotechnologies, 2012
Wastes from the leather industry as well as insoluble and hard-to-degrade animal proteins are cur... more Wastes from the leather industry as well as insoluble and hard-to-degrade animal proteins are currently eliminated by incineration, method with high ecological disadvantages. In order to avoid these inconvenients, microbiological and/or enzymatic methods are examined. Leather degradation was performed in two trials: one enzymatic-assisted and the other microbial-assisted. Enzymatic hydrolysis of collagen, the representative protein of leather, was performed with collagenase type IA, with six enzyme concentrations, for up to 10 days. The hydrolysis yield was evaluated by free amino acids determination. Microbial hydrolysis involved 35 bacterial strains belonging to various genera (Streptomyces, Bacillus, Pseudomonas, Serratia etc), screened for their ability of growth in minimal medium containing bovine leather, ovine leather or wool as unique carbon or nitrogen sources. Three of these strains: Bacillus licheniformis ATCC 14580, Pseudomonas fluorescens ATCC 13525 and a new bacterial ...
Increasing the shelf life of bread and food security can be achieved through biological (sourdoug... more Increasing the shelf life of bread and food security can be achieved through biological (sourdough fermented by microbial strains with inhibitory activity), chemical (calcium propionate, essential oils), and physical (packaging system) methods. There were evaluated the synergistic effects of rye sourdough fermented by Lactobacillus plantarum (strains C71, C78 and C81) and calcium propionate or essential oils (onion, garlic, oregano) on the fermentation of the wheat dough. In relation to the flour amount, preservatives were used in percentage of 0.2% (w/w) for the rye sourdough, 0.1% to 0.2% (w/w) for calcium propionate and 0.1% (v/w) for essential oils. Microbiological (lactic acid bacteria and yeasts), biochemical (pH, total titrable acidity, lactic and acetic acids) and molecular genetics of Lactobacillus plantarum strains testing were performed on bread dough. Microbiological analysis of wheat dough with adding of rye sourdough and calcium propionate or essential oils showed that...
Biomedicines
Vegetable juices are new carrier variants for beneficial bacteria, representing an alternative to... more Vegetable juices are new carrier variants for beneficial bacteria, representing an alternative to dairy-fermented products, especially for vegan, strict vegetarian, or allergic consumers. The aim of this study was to characterize several Romanian native lactic acid bacteria (LAB) strains to select valuable nutritional and probiotic strains for vegetable juice fermentation. Nineteen LAB strains were analyzed for antibiotic susceptibility (disc-diffusion method), the presence of antibiotic resistance genes, the presence of functional genes. and the production of organic acids by HPLC. Antibiotic resistant strains were observed only with ampicillin (Amp10) and kanamycin (K30), 79% and 32%, respectively, with results partially confirmed by molecular analysis. Multiplex PCR revealed the presence of LBA1272, dltD, folP, agl, α-amy, malL, and ribA genes, related to stress resistance, starch metabolism, and production of vitamins, except for folK. HPLC analyses were performed on beet roots ...
Scientific Bulletin. Series F. Biotechnologies, 2020
Xylanases have numerous applications in various fields, thus presenting an immense interest in st... more Xylanases have numerous applications in various fields, thus presenting an immense interest in studying. The sources for these enzymes include bacteria, fungi, yeast and others, the most important producers being fungi. The focus of this study was on enhancing the fungal strain ability to produce xylanase using random mutagenesis. Several mutants from Aspergillus brasiliensis and Penicillium digitatum were obtained through physical and chemical mutagenesis from strains previously selected as xylanase producers. The Petri plates with the fungal spores were exposed to UV light for physical mutagenesis at the distance of 10 cm and for 5-50 minutes. The chemical mutagenesis involved the use of N-methyl-N′-nitro-N-nitrosoguanidine and ethyl methane sulfonate, by adding in the Petri plates with the fungal spores 150 µg/ml mutagen (N-methyl-N′-nitro-N-nitrosoguanidine or ethyl methane sulfonate). After both physical and chemical mutagenesis, several mutant strains were randomly selected an...
Hemicellulose, the second most abundant natural polymer on earth, is a mixture of polysaccharides... more Hemicellulose, the second most abundant natural polymer on earth, is a mixture of polysaccharides and vegetable gums, found, together with cellulose and lignin, in plant cell walls. Xylanases are enzymes involved in the hydrolysis of xylan, the major component of hemicellulose. These enzymes are able to hydrolyze xylan, by breaking the β-1,4-glycoside linkages, in order to produce xylose and other degradation compounds. Many degrading microorganisms such as fungi, bacteria, yeast etc. have been found to produce xylanases. In this study, our aim was to test different strains regarding their ability to produce xylanases. A screening of the bacterial and fungal strains was performed in order to select the microorganisms that could produce higher amount of xylanases. The strains were cultivated on minimal agar medium with 0.5% oat spelt xylan as the carbon source. The plates were incubated at 28oC, for three to ten days (depending on microorganism) and analyzed at every 24 hours for the...
“Agriculture for Life, Life for Agriculture” Conference Proceedings, 2018
Rosa canina L. fruit have been used internally as tea for treatment of viral infections and disor... more Rosa canina L. fruit have been used internally as tea for treatment of viral infections and disorders of the kidneys and urinary tract. Also, it was reported that the R. canina fruit, with its high ascorbic acid, phenolics and flavonoids contents, have antioxidant, antimutagenic and anticarcinogenic effects. Antioxidants neutralize free radicals, which cause oxidative damage to lipids, proteins, and nucleic acids and thus protect the organism. Research studies conducted on this topic have shown that natural antioxidants are involved in protection against many diseases: cancer, cardiovascular diseases and osteoporosis. Different processing and storage methods of the fruit could affect the bioactive nutrients while preserving the antioxidant capacity of them is very important. The aim of this study was to evaluate the effect of storage in a dry or frozen state on the antioxidants content of R. canina fruit. The evaluation involved determination of carotenes, ascorbic acid and total po...
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Animal Science and Biotechnologies, 2018
The focus of this article is to provide informations about soil enzymatic activity as a biologica... more The focus of this article is to provide informations about soil enzymatic activity as a biological indicator for impacts of pesticides on soils. In this experiment, an ecological soil was treated with two types of fungicide (Ridomil Gold and Bravo 500) and two of insecticides (Mospilan 20SG and Vertimec 1.8% EC). The pesticides were assessed for their effect on different enzymatic activities. They were administrated over a 28 days period and the samples of soil were taken once every 7 days and analyzed in the laboratory. For each sample was determined the enzymatic activity, pH, humidity. The enzymatic activity was assessed using colorimetrical methods. Enzymes chosen for this study were cellulase, amylase, xylanase, urease, alkaline and acid phosphatase. Results shown that the enzymatic activity can increase or decrease when the soil was treated with the fungicides and insecticides chosen for this experiment.
Toxicon : official journal of the International Society on Toxinology, 2011
The mycotoxin deoxynivalenol (DON), a contaminant of certain foods and feeds, is cytotoxic and ge... more The mycotoxin deoxynivalenol (DON), a contaminant of certain foods and feeds, is cytotoxic and genotoxic to mammalians cells. Exposure of human embryonic kidney (Hek-293) cells to DON led to a dose- and time-dependent decrease in cell viability, with an IC(50) about 7.6 μM. The DON effects on Hek-293 morphology, reactive oxygen species, lipid peroxidation and antioxidative system and caspase 3 and bcl-2 expression were studied. Cells became round and in some are progressive loss of cell attachment appeared. These biochemical parameters were assessed after 6, 12 and 24 h of treatment with 2.5 and 5 μM DON. An increase in superoxide dismutase activity within the interval 6-12 h and almost complete recovery by the end of experiment for both concentrations was observed, whereas the profile of catalase activity was the same with the superoxide dismutase one for 2.5 μM and decreased in a time-dependent manner for 5 μM. A temporary activation of glutathione peroxidase and glutathione reduc...
Current Opinion in Biotechnology, 2013
Among numerous lactic acid bacteria strains isolated from autochthonous smoked fresh cheeses, pot... more Among numerous lactic acid bacteria strains isolated from autochthonous smoked fresh cheeses, potential probiotic strains were selected according to strict probiotic selection criteria. Further research revealed that the strain MCD6 was actually a coculture of two Lactobacillus plantarum strains which were identified as L. plantarum D13 and L. plantarum D6, where L. plantarum D6 expresses surface S-layer proteins of approximately 45 kDa. Since S-layer proteins, to our knowledge, have never been identified among representatives of L. plantarum species, it was of our great interest to further characterise and study its functional role in probiotic activity. Hence, the S-layer functional role in probiotic activity of coculture L. plantarum D6 and L. plantarum D13 through the comparison of important functional activities of probiotic strains was evaluated. Aggregation and coaggregation abilities, adhesion to intestinal epithelial cells in vitro, pathogen exclusion and survival in simulated conditions of gastrointestinal tract and during freeze drying, before and after guanidine hydrochloride extraction of S-layer proteins were examined in coculture and monocultures of L. plantarum D13 and L. plantarum D6, respectively. As a result it was established that coculture of two L. plantarum strains enhances their probiotic activity due to the S-layer protein of L. plantarum D6 strain.
Current Opinion in Biotechnology, 2013
Molecular identification of 85 fungal isolates from Romanian wheat cultivars collected between 20... more Molecular identification of 85 fungal isolates from Romanian wheat cultivars collected between 2007 and 2008 was performed by PCR assays using specific primer pairs for F. graminearum, F. culmorum and F. sporotrichoides. Chemotype determination was achieved with primers for four genes involved in trichothecene biosynthesis (tri3, tri7, tri12 and tri13). The pathogenity of 19 Fusarium isolates against two wheat cultivars was tested and deoxynivalenol content was achieved by HPLC-RP assays. PCR analysis revealed that F. graminearum was the most prevalent species, representing 83.5%. The amplicon produced by primer set tox5-1/tox5-2 was present in 88.23% of the tested Fusarium isolates, indicating their thricothecene biosynthesis potential. Molecular analysis proved no nivalenol producers in the tested isolates, shown that all F. culmorum isolates were 3- acetyldeoxynivalenol chemotype and all F. graminearum isolates were 15- acetyldeoxynivalenol chemotype. Pathogenity test resulted in...
The toxicity of zearalenone (ZEA) was evaluated in swine spleen, a key organ for the innate and a... more The toxicity of zearalenone (ZEA) was evaluated in swine spleen, a key organ for the innate and adaptative immune response. Weaned pigs were fed for 18 days with a control or a ZEA contaminated diet. The effect of ZEA was assessed on wide genome expression, pro- (TNF-α, IL-8, IL-6, IL-1β, IFN-γ) and anti-inflammatory (IL-10, IL-4) cytokines, other molecules in-volved in inflammatory processes (MMPs/TIMPs), as well as signaling molecules, (p38/ JNK1/JNK2-MAPKs) and nuclear receptors (PPARγ/NFkB/AP-1/STAT3/c-JUN). Microarray analysis showed that 46 % of total number of differentially expressed genes was involved in cellular signaling pathway, 13 % in cytokine network and 10 % in the inflammatory response. ZEA increased expression and synthesis of pro- inflammatory (TNF-α, IL-8, IL-6, IL-1β) and had no effect on IFN-γ, IL-4 and IL-10 cytokines in spleen. The inflammatory stimulation might be a consequence of JNK pathway activation rather than of p-38MAPK and NF-kB in-volvement whose ge...
Scientific Bulletin. Series F. Biotechnologies, 2013
The industrial processing of leather has a high environmental impact due to the heavy use of poll... 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...
VASILICA MANEA1*, CRISTINA STURZOIU2, GHEORGHE CAMPEANU3, GEORGETA RADULESCU1, FLORENTINA ISRAEL-... more VASILICA MANEA1*, CRISTINA STURZOIU2, GHEORGHE CAMPEANU3, GEORGETA RADULESCU1, FLORENTINA ISRAEL-ROMING3, ANGELA CASARICA1, GHEORGHE STOIAN2 1 National Institute For Chemical Pharmaceutical Research and Development ICCF Bucharest, 112 Vitan Avenue, 031299, Bucharest, Romania 2 University of Bucharest, Faculty of Biology,, Department of Biochemistry and Molecular Biology, 91-95 Splaiul Independentei , 050095, Bucharest, Romania 3 Applied Biochemistry and Biotechnology Center BIOTECHNOL, 59 Mãrãoti, 011464, Bucharest, Romania
Scientific Bulletin. Series F. Biotechnologies, 2014
Biodegradation of fibrous protein is a challenge due to the resistance of the raw material. Enzym... 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...
Sweet sorghum is a great energy crop that shows the benefits to ecosystems, energy and economics,... more Sweet sorghum is a great energy crop that shows the benefits to ecosystems, energy and economics, being a valuable source of energy of the category 1st, 2nd and 3rd. bioethanol generation. Purpose of the paper is to study the chemical composition of sweet sorghum stalks depleted in carbohydrates with applications in obtaining ethanol. It shows appreciable compositional values of free sugars, starch, cellulose, hemicellulose and lignin. All these components can be easily made available as fermentable carbohydrates leading to the production of products with high economic value (bioethanol).
Romanian Biotechnological Letters, 2021
Camelina sativa is well-known for its polyunsaturated fatty acids content. Beside the lipidic pro... more Camelina sativa is well-known for its polyunsaturated fatty acids content. Beside the lipidic profile, the seeds contain phenolic compounds with antioxidant, antimicrobial and anticarcinogenic activity. This study aims to assess the antimicrobial activity of some camelina extracts, using the disc diffusion assay. Camelina oil and seed extracts in tree types of hydroalcoholic solvents (ethanol, i-propanol and methanol) were used in this study. All these were evaluated for antimicrobial activity against six different human pathogens: Bacillus cereus, Salmonella typhimurium, Enterococcus faecalis, Staphylococcus aureus, Candida albicans and Candida parapsilosis, and other five plant pathogens: Botrytis cinerea, Fusarium oxysporum, Monilinia sp., Penicillium sp. and Sclerotium sp. B. subtilis ATCC 6633 was used as reference, due to its high sensitivity to antimicrobial compounds. Three methods to obtain hydroalcoholic extracts were tested. The 90% propanolic extracts have shown the high...
The amount of Ochratoxin A in must and wine is strongly influenced by the pre- and post- harvesti... more The amount of Ochratoxin A in must and wine is strongly influenced by the pre- and post- harvesting conditions and the vinification techniques. The effect of pre- and post-harvesting conditions on Ochratoxin A biosynthesis depends mainly on the geo-climatic particularities of the grapes cultivation area. The pre-harvesting conditions that affect Ochratoxin A level in wine and related products are: climatic factors, vineyard location and grape variety. This paper refers to the correlation of these factors. The contamination with Ochratoxin A was analyzed in 99 wine samples (55 white wine and 44 red wine), 8 varieties produced in Vaslui, Vrancea, Prahova, Constanta, Arges, and Dolj vineyards, during 2007 - 2010. Ochratoxin A determination was performed by HPLC-FLD method with immunoaffinity clean-up. 32.7% of the white wine samples and 38.6 % of red wine samples were contaminated with levels ranging from 0.06 up to 0.99 ng ml -1 for white wine and from 0.19 up to 1.89 ng ml -1 . The m...
Uploads
Papers by Florentina Israel Roming