The study of the intra-specif ic phylogenetic structure of Leuconostoc oenos is essential to understand the participation of several strains in malo-lactic fermentation (MLF). RFLP of the PCR-amplified 165-23s rDNA intergenic spacer region (ISR) was performed in Leuc. oenos and other related species. The RFLP patterns with seven endonucleases were identical for the 37 Leuc. oenos strains, but differed from those obtained for all other species tested. This method could provide an invaluable insight for molecular identification of the wine leuconostocs. The RFLP relationships of members of the genera Leuconostoc and Weissella were highly similar t o those previously reported by 165 and 235 rRNA sequencing studies. The 16S-235 rDNA ISR was sequenced in five strains of Leuc. oenos. A single tRNAAia was detected. The ISR sequence seems to be identical in the two rRNA (rrn) operons found in Leuc. oenos and no significant sequence variation was observed between strains that revealed relative differences as previously shown by PFGE. Results from the present study demonstrated that Leuc. oenos is phylogenetically a very homogeneous species (according to DNA-DNA hybridization studies) and sustain that this species is different from the genus Leuconostoc. The extremely conserved ISR of these organisms suggests that Leuc. oenos strains currently isolated and characterized must have spread with the transfer of viticulture rather than coming from indigenous populations.

Erythrina edulis Triana ex Micheli is a protein-enriched legume traditionally used for both dietary and medicinal purposes. In this paper, protein concentrate was obtained from the seed flour. SDS-PAGE analysis revealed a high number and intensity of bands in the range between 10 and 90 kDa. Neutrase ® , Flavourzyme ® , and Alcalase ® were used to hydrolyze the protein concentrate at different times. By SDS-PAGE, the lower resistance of proteins to Alcalase ® action was observed, providing hydrolyzates with higher radical scavenging activity. The 120 min-hydrolyzate showed ORAC and TEAC values of 2.51 and 0.91 mol Trolox equivalents/mg of protein, respectively. A fraction lower than 3 kDa and rich in hydrophobic and aromatic amino acids was demonstrated to be mainly responsible for the observed activity. E. edulis could be a new alternative in the formulation of functional foods not only for its high protein content but also for the potential biological properties of its hydrolyzates.

Paraoxonase-1 (PON1) is a serum esterase associated with high density lipoproteins and capable of detoxifying toxic metabolites of organophosphorus (OP) compounds. Two major polymorphisms have been described in the coding region of the PON1 gene at positions 192 and 55 and at least five in the 5 0 -regulatory region, the most important at position À108. Depending on the substrate, PON1 192 Q/R polymorphism can affect PON1 enzymatic activity. In the present study, we have determined the distribution of the PON1 192 Q/R and À108 C/T polymorphisms in a Peruvian population and compared the distribution of these polymorphisms with those of other world populations. PON1 phenotype and enzyme activity also were measured as they can influence the population resistance to the toxicity of OP compounds. The genotype distribution at position 192 was: QQ ¼ 0.236, QR ¼ 0.607, and RR ¼ 0.157; and distribution at position À108 was: CC ¼ 0.315, CT ¼ 0.596, and TT ¼ 0.089. The frequencies of the high activity R and C alleles were 0.461 and 0.613, respectively. The frequency of the PON1 192 Q allele was significantly lower than that of American, Caucasian-American, European-Brazilian, and Costa Rican samples. Outside the American continent, the frequency of this allele was lower than for all European countries, Thais, and Indians, but higher than for Chinese or Japanese. Regarding the toxicological importance of these polymorphisms, it was inferred that PON1 phenotyping (assessment of the R alloform) and genotyping (determination of the PON1 -108TT genotype) could be helpful as individual markers of susceptibility. PON1 phenotyping may be useful in further epidemiological studies involving agriculture workers occupationally exposed to OP compounds in developing countries. Environ. Mol. Mutagen. 47:699-706, 2006. V V C 2006 Wiley-Liss, Inc.

The intraspecific genetic diversity of Oenococcus oeni, the key organism in the malolactic fermentation of wine, has been evaluated by random amplified polymorphic DNA (RAPD), ribotyping, small-plasmid content, and sequencing of RAPD markers with widespread distribution among the strains. Collection strains representing the diversity of this species have been studied together with some new isolates, many of which were obtained from wines produced by spontaneous malolactic fermentation. The RAPD profiles were strain specific and discerned two main groups of strains coincident with clusters obtained by macrorestriction typing in a previous work. Ribotyping and the conservation of RAPD markers indicates that O. oeni is a relatively homogeneous species. Furthermore, identical DNA sequences of some RAPD markers among strains representative of the most divergent RAPD clusters indicates that O. oeni is indeed a phylogenetically tight group, probably corresponding to a single clone, or clonal line of descent, specialized to grow in the wine environment and universally spread.

BACKGROUND: Oxidative reactions are responsible for the changes in quality during food processing and storage. Oxidative stress is also involved in multiple chronic diseases, such as cardiovascular and neurodegenerative disorders, diabetes, cancer, and aging. The consumption of dietary antioxidants has been demonstrated to help to reduce the oxidative damage in both the human body and food systems. In this study, the potential of Erythrina edulis (pajuro) protein as source of antioxidant peptides was evaluated.RESULTS: Pajuro protein concentrate hydrolyzed by alcalase for 120 min showed potent ABTS ·+ and peroxyl radical scavenging activity with Trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) values of 1.37 ± 0.09 mol TE mg −1 peptide and 2.83 ± 0.07 mol TE mg −1 peptide, respectively. Fractionation of the hydrolyzate to small peptides resulted in increased antioxidant activity. De novo sequencing of most active fractions collected by chromatographic analysis enabled 30 novel peptides to be identified. Of these, ten were synthesized and their radical activity evaluated, demonstrating their relevant contribution to the antioxidant effects observed for pajuro protein hydrolyzate. CONCLUSIONS: The sequences identified represent an important advance in the molecular characterization of the pajuro protein, demonstrating its potential as a source of antioxidant peptides for food and nutraceutical applications. Oxygen radical absorbance capacity (ORAC) assayThe oxygen radical absorbance capacity (ORAC) was determined following the protocol described by Hernández-Ledesma et al. 26 The final assay mixture (200 μL) contained FL (30 nmol L −1 ), AAPH (12 mmol L −1 ), and antioxidant (Trolox (0-5 nmol L −1 ) or sample J Sci Food Agric 2019; 99: 2420-2427 Identification of antioxidant peptidesFraction UF-3, containing peptides < 3 kDa, was selected for further purification. The different fractions collected by elution wileyonlinelibrary.com/jsfa

Lupinus mutabilis (tarwi) is a cultivated legume used principally as a protein source in human and animal nutrition. In this study, protein concentrate was obtained from debittered and defatted tarwi seed flour. SDS-PAGE analysis revealed the presence of highly intense bands ranged between 35 and 60 kDa. Tarwi protein concentrate was subjected to the action of alcalase to produce hydrolyzates with antioxidant activity. A central composite design was employed to study the effect of the experimental variables, enzyme/substrate ratio and incubation time, on the degree of hydrolysis and the radical scavenging capacity. The influence of both variables on the variable responses was demonstrated. The optimal conditions to obtain the highest degree of hydrolysis were enzyme/substrate ratio of 1.72% and 133 min of incubation. The highest radical scavenging activity (TEAC value of 2.7 ± 0.1 μmol Trolox equivalents/mg protein and ORAC value of 3.8 ± 0.1 μmol Trolox equivalents/mg protein) was found in hydrolyzates with alcalase after 138 min and an enzyme/substrate ratio of 1.87%. Peptides released by the action of alcalase and containing hydrophobic and aromatic amino acids could contribute to the antioxidant effects observed. Tarwi proteins could be a new alternative as a food additive with antioxidant properties or as an ingredient of functional foods for health promotion and prevention of free radical-induced chronic diseases.

Strains of the bacterium Ornithobacterium rhinotracheale (ORT), a causal agent of respiratory diseases in birds, were microbiologically isolated, identified, and molecularly characterized. Blood-enriched culture media and biochemistry tests were used for microbiologic identification. Polymerase chain reaction (PCR) and repetitive extragenic palindromic PCR (rep-PCR) techniques were used for molecular identification and characterization, respectively, of the microorganism. ORT strains were isolated in enriched media from the trachea and air sacs of broilers, breeders, and layers from several geographic zones of Peru. Of the original 75 strains isolated from 75 clinical samples from which ORT was recovered during 1998-2000, 25 were selected for further study based on ORT as the primary pathogenic isolate (no other pathogens were detected). Selected isolates were molecularly identified and characterized by PCR using specific primers designed from the conserved zones of the 16S ribosomal genes. Primers used for the identification of ORT produced a specific fragment of 784 base pair (bp), which did not appear in Haemophilus paragallinarum or Pasteurella multocida, microorganisms with similar morphologic and biochemical characteristics that produce dinical signs identical to those of ORT. All 25 strains of ORT tested with rep-PCR had a genetic profile similar to that of ORT American Type Culture Collection 51463, indicating the presence of only one genotype in the ORT strains studied.

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