Ontogeny and total sugar content of yacon tuberous roots and other three Smallanthus species (Heliantheae,Asteraceae), insights on the development of a semi-domesticated crop

The ontogeny of the tuberous roots of yacon (Smallanthus sonchifolius), an ancient Andean crop, is described for the first time along with three other wild species of Smallanthus: S. connatus, S. macroscyphus and S. siegesbeckius. Tuberous storage roots are present in the four species. Tuberization results from unusual secondary thickening. A meristematic endodermis maintains the primary cortex by generating cortex cells continuously. Secretory schizogenous canals develop adjacent to the endodermis in opposition to the phloem poles. Phellogen originates in the outer layers of the parenchymatic cortex. The four species develop a parenchymatous pith that stores mainly fructooligosacharides (FOS) and plays an important role in storing water, protecting the plant from drought stress and environmental hazards in the Andean climate. In yacon, domestication has produced a wide pith that stores water, reducing sugars and FOS with low degree of polimerization, that could have eventually made it more palatable as compared to the wild counterparts.     

Physicochemical changes in the hull of corn grains during their alkaline cooking

The alkaline cooking of corn in a solution of Ca(OH)2 to produce corn-based foods is oriented to make corn proteins available, to incorporate Ca to the cooked grains, and also to remove the corn hull. This process (nixtamalization) is known in Mexico and Guatemala from prehispanic times; however, the effect of the alkaline cooking on the corn hull remains poorly documented. In this work, the physicochemical changes that take place in the corn hull during its cooking in a saturated solution of Ca(OH)2 were studied using infrared, X-ray diffraction, 13C cross-polarization/magic-angle spinning (CP/MAS) NMR, confocal imaging microscopy, differential scanning calorimetry, and thermogravimetry techniques. The main effect of this treatment on the hull is the removal of hemicelluloses and lignin, increasing the hull permeability and, as a consequence, facilitating the entry of the alkaline solution into the corn kernel. No significant changes were observed in the cellulose fiber network, which remains as native cellulose I, with a crystalline index, according to 13C CP/MAS NMR spectra, of 0.60. The alkaline treatment does not allow the cellulose fibers to swell and their regeneration in the form of cellulose(II). It seems any attempt to make use of the Ca binding capacity of the hull to increase the Ca availability in nixtamalized corn-based foods requires a separated treatment for the hull and kernel. On alkaline cooking, the hull hemicellulose fraction dissolves, losing its ability to bind Ca as a way to incorporate this element into foods elaborated from nixtamalized corn.     

Favus in a fighting cock caused by Microsporum gallinae

The first diagnosis of favus in chickens in Costa Rica was made in a 1-year-old fighting cock that had lesions surrounding the comb. The etiologic agent was isolated and identified as Microsporum gallinae. The rooster recovered during topical treatment with tolnaftate and oral treatment with griseofulvin.     

Serodiagnosis of leptospirosis in pigs using an axial filament enzyme-linked immunosorbent assay.

The axial filament (AF) from Leptospira interrogans serovar canicola was isolated by cesium chloride density gradient centrifugation of 2% sarcosyl treated whole cells. Isolation of AF was confirmed by electron microscopic examination, by protein-A immunogold labelling, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), and immunoblotting. Analysis by SDS-PAGE of the purified preparation showed relatively weak bands of molecular size 41 kDa and 21 kDa, and strong bands of 35 kDa and 34.5 kDa. Immunoblot analysis using antiserum to the AF against sonicated leptospires of a variety of serovars showed prominent reaction against the 41, 35, and 34.5 kDa protein bands, as well as against minor bands of molecular weight 43, 39, and 37 kDa. Antisera prepared against leptospiral serovars also identified minor bands at 33 and 32 kDa. Immunoblots with antiserum to whole cells of serovar bratislava detected the 35 and 34.5 kDa AF bands of Borrelia burgdorferi moderately and of Treponema hyodysenteriae only slightly in comparison to leptospiral AF. Antibody to B. burgdorferi did not detect the leptospiral AF antigen. Immunoblots with antiserum to T. hyodysenteriae showed a marked reaction with a 41 kDa band of B. burgdorferi but only a very minor reaction with leptospiral AF. The AF was tested in an AF-ELISA against sera from 260 pigs, many of which reacted in the microscopic agglutination test (MAT) against one or more leptospiral serovars. A sensitivity of 97.1% and a specificity of 93.1% was determined in comparison to the MAT. Only moderate correlation was observed between titres detected in the AF-ELISA and the MAT (r = 0.4). When sonicated whole cells (WC) of serovar canicola were used in an ELISA (WC-ELISA), high correlation was observed between AF-ELISA and WC-ELISA (r = 0.97). These findings show that the AF-ELISA can be used effectively as a species-specific antigen for the serological diagnosis of leptospirosis in swine and that sonicated whole cells can substitute excellently for purified AF as the antigen source. These findings may be extrapolated to the use of AF in immunodiagnosis of leptospirosis in other species.     

Antioxidant and Antimutagenic Activities of Mexican Oregano (Lippia graveolens Kunth)

Free essential oil methanolic extracts from three different geographical populations of Lippia graveolens in México were screened for antioxidant and antimutagenic properties by the DPPH and Kado microsuspension assay, respectively. Total phenolic and flavonoid contents as well as HPLC identification and quantification of naringenin and rosmarinic acid were also carried out. In addition, a taxonomical phenetic analysis was performed. The L. graveolens extracts showed varying content of phenols and flavonoids. Significant concentration of rosmarinic acid was found for the first time in the species. All the extracts were capable of scavenging DPPH radicals in a concentration dependent fashion; the IC₅₀ values correlate with the phenolic content. None of the extracts was toxic to TA100 and TA98 strains at the concentrations tested; moreover, the extracts at a concentration equivalent to 200 μg of gallic acid inhibited a 39 and 30% the mutagenicity induced by 4-nitro-o-phenylenediamine and sodium azide, respectively. The results suggest that the Mexican oregano is a source of polar bioactive ingredients for the food industry.     

Effects of soaking in aqueous acidic and alkali solutions on removal of polyphenols and in vitro digestibility of cowpea

Mature dark red seeds of cowpea (Vigna unguiculata (L.) Walp.) UPL Cp 3, were subjected to several soaking treatments to remove their polyphenols. Soaking in water at room temperature for 8 and 24 h resulted in 17% and 21% loss of assayable polyphenols, respectively. Dilute solutions of alkali (Na₂CO₃, NaHCO₃, NH₄OH and KOH) and acid (CH₃ COOH, HCl and H₂ SO₄) were more effective in removing polyphenols up to 88% than higher concentrations of alkali and acid solutions.Vinegar (0.005–0.65 M CH₃ COOH) decreased polyphenols from 55 to 62% with a 6 to 14% improvement in in vitro protein digestibility (IVPD). Commercial lime (65% CaO) removed polyphenols from seeds soaked for 8 to 24 h by 70% with 2 to 10% increase in in vitro protein digestibility. Ash removed 40 to 60% of the polyphenols after 8 and 24 h of soaking with an increase in IVPD of 7 to 13%. Total polyphenols were significantly correlated (+0.92**) with protein precipitable polyphenols (condensed tannins).     

Toxicity of cultured bullseye puffer fish Sphoeroides annulatus

The toxin content in various life cycle stages of tank-cultivated bullseye puffer (Sphoeroides annulatus) were analyzed by mouse bioassay and ESI-MS spectrometry analysis. The presence of toxin content was determined in extracts of sperm, eggs, embryo, larvae, post-larvae, juvenile, pre-adult, and adult fish, as well as in food items used during the cultivation of the species. Our findings show that only the muscle of juveniles, the viscera of pre-adults, and muscle, liver, and gonad of adult specimens were slightly toxic (<1 mouse unit). Thus, cultivated S. annulatus, as occurs with other cultivated puffer fish species, does not represent a food safety risk to consumers. This is the first report of toxin analysis covering the complete life stages of a puffer fish under controlled conditions.     

Signatures of adaptation to obligate biotrophy in the Hyaloperonospora arabidopsidis genome

Many oomycete and fungal plant pathogens are obligate biotrophs, which extract nutrients only from living plant tissue and cannot grow apart from their hosts. Although these pathogens cause substantial crop losses, little is known about the molecular basis or evolution of obligate biotrophy. Here, we report the genome sequence of the oomycete Hyaloperonospora arabidopsidis (Hpa), an obligate biotroph and natural pathogen of Arabidopsis thaliana. In comparison with genomes of related, hemibiotrophic Phytophthora species, the Hpa genome exhibits dramatic reductions in genes encoding (i) RXLR effectors and other secreted pathogenicity proteins, (ii) enzymes for assimilation of inorganic nitrogen and sulfur, and (iii) proteins associated with zoospore formation and motility. These attributes comprise a genomic signature of evolution toward obligate biotrophy.     

Genital lesions in an outbreak of caprine contagious agalactia caused by Mycoplasma agalactiae and Mycoplasma putrefaciens

This paper reports on the genital lesions observed in adult male and female goats from a commercial flock in the Extremadura region of southwestern Spain, following an outbreak of contagious agalactia syndrome caused by Mycoplasma agalactiae and M. putrefaciens. Although both species were isolated from several organs, M. putrefaciens was the only agent isolated from the genital lesions reported here, characterized by desquamative salpingitis and cystic catarrhal metritis in females and by testicular degeneration in males. Mycoplasma putrefaciens was isolated from the testes of only one of the males examined.