Search results for "RAPD"
showing 10 items of 84 documents
Use of selected autochthonous lactic acid bacteria for Spanish-style table olive fermentation
2012
The present work presents a successful attempt to achieve an enhanced and more predictable fermentation process in Spanish-style green olive technology by selection and use of autochthonous starter cultures. During the first phase of this work, two Spanish-like fermentations of green table olives of cultivar (cv) “Nocellara del Belice”, coming from irrigated and not irrigated fields, were monitored, in order to highlight the best agricultural conditions for drupe production and to isolate lactic acid bacteria strains with relevant technological properties. Among 88 identified isolates, one Lactobacillus pentosus strain showed remarkable biochemical features and high acidification rate in sy…
Preliminary characterization of wine lactobacilli able to degrade arginine
2002
Lactobacillus strains able to degrade arginine were isolated and characterized from a typical red wine. All the strains were gram-positive, catalase-negative and produced both D- and L-lactate from glucose. Strains L2, L3, L4, and L6 were able to produce CO2 from glucose; however, production of CO2 from glucose was not observed in strains L1 and L5, suggesting that they belong to the homofermentative wine lactic acid bacteria (LAB) group. All of the lactobacilli were tested for their ability to ferment 49 carbohydrates. The sugar fermentation profile of strain L1 was unique, suggesting that this strain belonged to Lactococcus lactis ssp. cremoris, a non-typical wine LAB. Furthermore, a prel…
Phenotypic and genotypic characterization of a new fish-virulent Vibrio vulnificus serovar that lacks potential to infect humans.
2007
Vibrio vulnificus is a bacterial species that is virulent for humans and fish. Human isolates are classified into biotypes 1 and 3 (BT1 and BT3) and fish isolates into biotype 2 (BT2). However, a few human infections caused by BT2 isolates have been reported worldwide (zoonosis). These BT2 human isolates belong to serovar E (SerE), which is also present in diseased fish. The aim of the present work was to characterize a new BT2 serovar [serovar A (SerA)], which emerged in the European fish-farming industry in 2000, by means of phenotypic, serological and genetic [plasmid profiling, ribotyping and random amplified polymorphic DNA (RAPD)] methodologies. The results confirmed that SerA constit…
Cryopreservation of Digitalis obscura selected genotypes by encapsulation-dehydration
2001
Shoot-tips from several genotypes of the cardenolide-producing perennial shrub Digitalis obscura L. were successfully cryopreserved using the encapsulation-dehydration technique. Precultivation on MS medium containing 0.5 M sucrose, followed by 2.5 h dehydration (final weight 30 %) induced shoot regrowth in 42 % of cryopreserved shoot-tips. Cold-hardening of the in vitro cultures before sucrose treatment dramatically increased shoot recovery up to 86 %. The optimized cryopreservation protocol was then employed using different shoot cultures from five D. obscura genotypes. Responses to cryopreservation depended mainly on the genotype, best results being obtained when shoot tips from HU3 and …
Molecular markers reflect differentiation of Fusarium oxysporum forma speciales on tomato and forma on eggplant
2013
Selective pressure induces pathogens to change their method of infection and, sometimes, causes species to become infectious. Pathogenic fungi must differentiate different morphological and physiological properties during the process of host specialization in their life cycle. In the present study, we conducted a genetic investigation and compared similarities within a generation of Fusarium oxysporum forma speciales (f. sp.) infecting tomato and forma (f.) infecting eggplants using selected ISSR and RAPD markers, two horticultural commodities belonging to the same taxon of the Solanaceae. Interestingly, genetic data showed that fungi belonging to F. oxysporum f. sp. infecting tomato have a…
Hybridization in Calopteryx damselflies: the role of males
2008
Females are often considered responsible for hybridization between two species because usually they are the choosier sex and their cooperation is needed for successful copulation. However, males can also be responsible for hybridization, for example in species in which males are able to force copulation. We studied the pattern of hybridization in two congeneric damselfly species, Calopteryx splendens and Calopteryx virgo, and provide evidence that F1 hybrids between the two damselfly species occur in the wild. According to mitochondrial DNA analysis, hybridization is reciprocal: five of seven hybrids were sired by C. splendens and two by C. virgo males. We conducted an experiment that revea…
Caracterización molecular de la pérdida del poder patógeno en Agrobacterium tumefaciens
2003
Agrobacterium tumefaciens es una bacteria fitopatógena causante de tumores en el cuello y raíces de muchas especies vegetales de interés económico. En los viveros e invernaderos es donde más daños produce, al aparecer episodios epidémicos que pueden impedir la comercialización de producciones enteras, porque las plantas afectadas por esta enfermedad no pueden ser comercializadas. Los estudios epidemiológicos y de dinámica de poblaciones del patógeno son poco abundantes y han incidido en aspectos del desarrollo y mantenimiento de la enfermedad producida por la bacteria. Aunque se ha señalado el predominio de cepas no patógenas frente a patógenas en ambientes en los que las cepas productoras …
Intraspecific diversity of Lactobacillus curvatus, Lactobacillus plantarum, Lactobacillus sakei, and Leuconostoc mesenteroides associated with vacuum…
2006
The intraspecific diversity of Leuconostoc mesenteroides, Lactobacillus curvatus, Lactobacillus sakei, and Lactobacillus plantarum was analyzed by randomly amplified polymorphic DNA (RAPD) PCR with universal primers M13 and T3. The study included 100 reference strains and 210 isolates recovered from two vacuum-packed Spanish meat products, fiambre de magro adobado and morcilla, previously identified by rDNA-restriction fragment length polymorphism profiles. The RAPD-M13 profiles identified isolates at species level in L. plantarum and L. mesenteroides, while RAPD-T3 provided profiles in L. sakei. The combination of RAPD-M13 and RAPD-T3 fingerprints revealed a total of 17 profiles in L. mese…
Identification and evaluation of antimicrobial resistance of enterococci isolated from raw ewes’ and cows’ milk collected in western Sicily: a prelim…
2019
The present work was carried out to investigate the Antimicrobial Resistance (AMR) of enterococci isolated from raw ewes’ and cows’ milk. The samples were collected from eighteen semi-extensive dairy sheep and cow farms throughout western Sicily. Plate counts, carried out on Rapid Enterococcus Agar commonly used to detect food enterococci, revealed a maximal enterococcal concentration of approximately 4.58 Log Colony Forming Unit (CFU)/mL. Colonies were isolated and differentiated based on genetic analysis by Randomly Amplified Polymorphic DNA (RAPD)-PCR. Thirty-eight different strains were identified. Analysis by a species-specific multiplex PCR assay grouped the strains into three Enteroc…
Ecological, morphological and genetic characterization of sympatric Haemonchus spp. parasites of domestic ruminants in Mauritania
1995
SUMMARYThe 4 species of ruminants (dromedary, zebu cattle, sheep and goat) in arid areas of Mauritania harboured Haemonchus spp. as the most frequent internal parasite. This was a rare situation where the 3 putative species, H. longistipes (dromedary), H. placet (zebu cattle) and H. contortus (sheep and goat) occurred sympatrically. The study was undertaken on hosts slaughtered at the Nouakchott abattoir, on the basis of monthly collection of worms. The environment was very unfavourable to H. placei and unfavourable to H. contortus, as intensity of infection remained low throughout the year, whereas infection in the dromedary was 10 to 20-fold higher. The survival strategies during the long…