Recent advances in Broomrapes research (REVIEW) |
Author : MARIA GEVEZOVA, TEODORA DEKALSKA, KIRIL STOYANOV, TSVETA HRISTEVA, KALOYAN KOSTOV, ROSSITZA BATCHVAROVA and ILIYA DENEV |
Abstract | Full Text |
Abstract :Orobanchaceae (broomrapes) is a morphologically diverse family of predominantly herbaceous, parasitic plants. The majority of species are facultative or obligate root parasites that subsist on broad-leaf plants, thereby depleting them of nutrients, minerals and water. The taxonomy status of the family Orobanchaceae among other flowering plants is often subject of debate. They possess only a few morphological features suitable for taxonomy purposes and yet even they are quite changeable. The variability within the species is too high and hampers the attempts to create proper determination keys. During last two decades several molecular markers were used for reevaluate taxonomy, biodiversity and phylogenetic relationships within the family. Recent investigations supported by molecular taxonomy analyses have resulted in re-definition of Orobanchaceae family. According to this classification Orobanchaceae consists of 89 genera, containing 2061 species. On the Balkans the family Orobanchaceae is represented by 3 genera: Orobanche includes 25 species; Phelipanche comprises of 9 species and some putative hybrids; Diphelypaea occurs with single species, Diphelypaea boissieri, in Macedonia and Greece. Only a few recent studies based on modern methods took place during last decade. Their findings confirmed differences between Phelipanche and Orobanche genera, but raised new question about their internal structure. Several broomrape species parasitize important crops. They are widely spread in Bulgaria, Southern Europe, Russia, Middle East and Northern Africa. They cause losses in crop productivity estimated at hundreds of millions of dollars annually than affect the livelihoods of 100 million farmers. A wide variety of approaches have been explored to control broomrapes, but none have been found to be sufficiently effective and affordable. The new findings about their life cycle and the recent genomic project focused on sequences of Ph. aegyptiaca genome open new perspectives for management of the harmful broomrape species and for understanding of their biology and evolution as well. |
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SSR marker-based molecular characterization and genetic diversity analysis of aromatic landreces of rice (Oryza sativa L.) |
Author : ABDUL M. SAJIB, MD. MUSHARAF HOSSAIN, A.T.M.J. MOSNAZ, HOSNEARA HOSSAIN, MD. MONIRUL ISLAM, MD. SHAMSHER ALI and SHAMSUL H. PRODHAN |
Abstract | Full Text |
Abstract :Molecular characterization of the genotypes gives precise information about the extent of genetic diversity which helps in the development of an appropriate breeding program. In the present study, a total of 24 SSR markers were used across 12 elite aromatic rice genotypes for their characterization and discrimination. Among these 24 markers 9 microsatellite markers were showed polymorphism. The number of alleles per locus ranged from 2 alleles (RM510, RM244, and RM277) to 6 alleles (RM 163), with an average of 3.33 alleles across 9 loci obtained in the study. The polymorphic information content values ranged from 0.14 (RM510) to 0.71 (RM163) in all 9 loci with an average of 0.48. RM163 was found the best marker for the identification of 12 genotypes as revealed by PIC values. The frequency of most common allele at each locus ranged from 41% (RM163, RM590, and RM413) to 91% (RM510). The pair-wise genetic dissimilarity co-efficient indicated that the highest genetic distance was obtained between Basmati PNR 346 and Deepa; Basmati PNR 346 and Patnai-23; Dolargura and Sugandha; Bhogganijia and Sugandha; and finally between Dolargura and Chinikani (88.89%). Opchaya, Basmati PNR 346 and Sugandha had close similarity among them but showed wide dissimilarity with other genotypes. Being grouped into distant clusters Dolargura and Opchaya could be utilized as potential parents for the improvement of fine grain aromatic rice varieties. Genotypes Deepa and Patnai-23 (having zero dissimilarity) might have possessed somewhat similar genetic background and more markers are needed to discriminate them. The microsatellite marker based molecular fingerprinting could serve as a sound basis in the identification of genetically distant accessions as well as in the duplicate sorting of the morphologically close accessions. |
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Bacterial interference with host epithelial junctional complexes: Probiotic bacteria vs. A/E lesion-forming Escherichia coli (REVIEW) |
Author : TANIA TOPOUZOVA-HRISTOVA, ELENA STEPHANOVA and STOYANKA STOITSOVA |
Abstract | Full Text |
Abstract :During colonization, enteropathogenic (EPEC) and enterohaemorrhagic (EHEC) Escherichia coli are capable to manipulate host cytoskeleton and colonize gut epithelia by a specific mode of attachment known as the attaching and effacing lesion (A/E lesion). While actin rearrangements during A/E lesion formation have been extensively investigated, the possible alterations of other cytoskeletal elements like those comprising the intercellular junctional complexes (JC) of polarized cells during infection have only lately attracted attention. The present mini-review addresses the opposite effects of two groups of bacteria, A/E lesion-forming pathogenic E. coli and probiotic bacterial strains, on JC. JC are important in maintaining gut barrier functions. EPEC and EHEC can disrupt JC which as a consequence leads to reduction in the transepitelial electrical resistance (TER) and an increase of the permeability to macromolecules. Probiotic bacteria on the other hand stabilize JC thus increasing TER and reducing permeability to macromolecular markers. Probiotic strains can protect JC integrity of polarized cells from the damage caused by EPEC or EHEC. Together with the promise of these results, of concern is the fact that the outcome of the studies can differ dependent on experimental protocols. Studies with living bacteria and different strain combinations have also put forward strain specific effects. Therefore, an important practical item for future studies is the identification of the molecules synthesized by probiotic bacteria that may be active on JC stability. |
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Physiological damage in Algerian mouse Mus spretus (Rodentia, Muridae) exposed to crude oil |
Author : FLAVIO M. R. DA SILVA JÚNIOR, RITA I. MONARCA, DEODÁLIA DIAS, MARIA G. RAMALHINHO, MARIA L. MATHIAS and ANA L. MUCCILLO-BAISCH |
Abstract | Full Text |
Abstract :Small mammals have been used to predict ecotoxicological damage caused by metals in field studies and laboratory exposure. In natural ecosystems, rodents play an important role either as seed dispersers or food providers for various predators since they represent intermediate links in the food chain. Several studies have already focused on the effects of metals on wild rodents, but data provided on the effects of organic contaminants, such as crude oil, are scarce. Among the possible biological indicators, physiological parameters are useful because they reflect, accurately, the organism-environment interaction. The current study aimed: I) to evaluate the effects of the exposure to soil contaminated by crude oil in the Mus spretus mice and II) to select sensitive markers to crude oil pollution. Mice collected in free-contaminated areas were exposed to artificial soil contaminated by crude oil, and compared with animals housed in artificial non-contaminated soil (control soil). External signs such as lethargy and alopecia were observed in the first days of exposure. However, no changes in animals' body weight were recorded although changes in relative weight of some organs (liver, spleen and lungs) were observed. Furthermore, results also revealed increase in basal metabolic rate and decrease in exploratory and locomotor activity. Exposure to soil contaminated also caused dysfunction of the adrenal glands measured through fecal corticosterone levels. Data obtained highlight the relevance of using ex situ models, such as wild mice, and suggest a set of biological markers to predict and monitor environmental damage caused by crude oil exposure. |
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Bioremediation potential of a newly isolate solvent tolerant strain Bacillus thermophilus PS11 |
Author : PAYEL SARKAR and SHILPI GHOSH |
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Abstract :The increased generation of solvent waste has been stated as one of the most critical environmental problems. Though microbial bioremediation has been widely used for waste treatment but their application in solvent waste treatment is limited since the solvents have toxic effects on the microbial cells. A solvent tolerant strain of Bacillus thermophilus PS11 was isolated from soil by cyclohexane enrichment. Transmission electron micrograph of PS11 showed convoluted cell membrane and accumulation of solvents in the cytoplasm, indicating the adaptation of the bacterial strain to the solvent after 48h of incubation. The strain was also capable of growing in presence of wide range of other hydrophobic solvents with log P-values below 3.5. The isolate could uptake 50 ng/ml of uranium in its initial 12h of growth, exhibiting both solvent tolerance and metal resistance property. This combination of solvent tolerance and metal resistance will make the isolated Bacillus thermophilus PS11 a potential tool for metal bioremediation in solvent rich wastewaters. |
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Study of the transgalactosylation activity of ß-galactosidase from a new strain Kluyveromyces lactis 3 |
Author : ILIA ILIEV and TONKA VASILEVA |
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Abstract :Beta-galactosidase (EC.3.2.1.23) is an important enzyme industrially used for the hydrolysis of lactose from milk and milk whey for several applications. Lately, the importance of this enzyme was enhanced by its galactosyltransferase activity, which is responsible for synthesis of transgalactosylated oligosaccharides that act as prebiotics with several beneficial effects on the consumers. ß-Galactosidase production by Kluyveromyces lactis 3 was studied in shake flask culture. The highest enzymatic activity was obtained at 10-th hour of the fermentation. The optimum temperature for transferase activity was 50°C. When incubated with 30% lactose in 50 mM phosphate buffer (pH 6.0) the enzyme can synthesize up to 41% galacto-oligosaccharides (GalOS). β-Galactosidase from strain Kluyveromyces lactis 3 produces mainly oligosaccharides with degree of polymerization (DP) 6 at 40°C and with DP 3 at 50°C. |
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Effects of carbon sources, oxygenation and ethanol on the production of inulinase by Kluyveromyces marxianus YX01 |
Author : JIAOQI GAO, LIJIE CHEN and WENJIE YUAN |
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Abstract :Inulinase is one of the most important factors in consolidated bioprocessing, which combines enzyme production, inulin saccharification, and ethanol fermentation into a single process. In our study, inulinase production and cell growth of Kluyveromyces marxianus YX01 under different conditions were studied. Carbon source was shown to be significant on the production of inulinase, because the activity of inulinase was higher using inulin as a carbon source compared with glucose or fructose. The concentration of the carbon source had a repressive effect on the activity of inulinase. When the concentration was increased to 60 g/L, inulinase activity was only 50% compared with carbon source concentration of 20 g/L. Enzyme activity was also strongly influenced by aeration rate. It has been shown that the activity of inulinase and cell growth under anaerobic conditions were maintained at low levels, but aeration at 1.0 vvm (air volume/broth volume minute) led to higher activity. Inulinase activity per unit biomass was not significantly different under different aeration rates. Ethanol had a repressive effect on the cell growth. Cells ceased growing when the level of ethanol was greater than 9% (v/v), but ethanol did not affect the activity of secreted inulinase and the enzyme was stable at ethanol concentration up to 15%. |
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A novel neutral protease from thermophilic Bacillus strain HUTBS62 |
Author : HAZEM AQEL, FAROUK AL-QUADAN and TAHANI K. YOUSEF |
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Abstract :A novel neutral highly thermostable protease was detected in the culture medium of thermophilic Bacillus strain HUTBS62 isolated from hot-spring located near to the Dead Sea, Jordan. The enzyme was purified by precipitation with 55-60% ammonium sulfate, gel filtration on Sephadex G-100 and DEAE ion exchange chromatography. The enzyme was purified 53-fold with 2% yield. The optimum pH and temperature for catalytic activity of protease was pH 6.8 and 80ºC, respectively, and 31% activity of protease remained even after heat treatment at 100ºC for 60 min. The relative activity of the enzyme was highly stable (90%) at 50ºC for 2 h. The half-life of the enzyme at 90ºC, 80ºC and 70ºC was estimated to be 3, 4 and 6 h, respectively. The activation energy of denaturation of purified enzyme was 21.7 kJmol-1. Iron, sodium, calcium, and manganese increased protease activity. On the other hand, magnesium, cobalt and zinc variably decreased the residual activity. But cadmium and copper drastically inhibited the enzyme activity. The enzymatic activity was highly stable in the presence of 1 and 2 mM EDTA at pH 6.8 and 80ºC. The neutral protease therefore could be defined as a highly thermostable with new properties make the present enzyme applicable for many biotechnological purposes. |
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Low temperature extraction of essential oil bearing plants by liquefied gases. 7. Seeds from cardamom (Elettaria cardamomum /L./ Maton) |
Author : VELIZAR GOCHEV, TANYA GIROVA, IVANKA STOILOVA, TEODORA ATANASOVA, NENO NENOV, VESELIN STANCHEV and ALBENA STOYANOVA |
Abstract | Full Text |
Abstract :The chemical composition of extract from the seeds of cardamom (Elettaria cardamomum (L.) Maton, obtained by extraction with tetrafluoroethane was analyzed using GC and GC/MS. The major compounds (concentration higher than 3%) of extract were: terpinyl acetate (36.8%), 1,8-cineole (29.2%), linalyl acetate (5.2%), sabinene (3.9%) and linalool (3.1%). The studied extract demonstrated antimicrobial activity against pathogenic species Staphylococcus aureus, S. epidermidis, Salmonella abony and was inactive against Pseudomonas aeruginosa. The extract possessed low antioxidant activity against DPPH radicals. |
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Biosorption of Cu (II) onto chemically modified waste mycelium of Aspergillus awamori: Equilibrium, kinetics and modeling studies |
Author : ZDRAVKA VELKOVA, MARGARITA STOYTCHEVA and VELIZAR GOCHEV |
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Abstract :The biosorption potential of chemically modified waste mycelium of industrial xylanase-producing strain Aspergillus awamori for Cu (II) removal from aqueous solutions was evaluated. The influence of pH, contact time and initial Cu (II) concentration on the removal efficiency was evaluated. Maximum biosorption capacity was reached by sodium hydroxide treated waste fungal mycelium at pH 5.0. The Langmuir adsorption equation matched very well the adsorption equilibrium data in the studied conditions. The process kinetic followed the pseudo-firs order model. |
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