Determination of potentially mycotoxigenic fungi in coffee (Coffea arabica L.) from Nayarit.

A total of fourteen roasted coffee samples were collected from different local markets in Nayarit, Mexico. Twenty-two fungi isolates were related to the genera Aspergillus (54.54%) and Penicillium (4.5%). The strains R16 (0.33 µg/kg), 6N (1.16 µg/kg) and 11 (0.36 µg/kg) tested positive for OTA (ochratoxin A) production in PDA, the other fungi samples were not toxigenic. According to the sequence analysis of their ITS1-5.8S-ITS2 rDNA region, fungi OTA producers correspond to A. niger, A. versicolor and Byssochlamys spectabilis. These three strains were able to produce OTA when inoculated in roasted coffee in concentrations ranging from 75 to 90 µg/kg, after 21 days. Different production stages of roasted coffee (crop management, postharvest practices and storage) along with environmental conditions do not ensure mycotoxigenic fungi free products. This is the first report of OTA natural occurrence in roasted coffee from Nayarit.

[Yeast irrigation enhances the nutritional content in hydroponic green maize fodder]. / La irrigación con levaduras incrementa el contenido nutricional del forraje verde hidropónico de maíz.

The objective of this study was to evaluate the effect of irrigation with yeasts (Debaryomyces hansenii var. Fabry, Yarowia lipolytica YIBCS002, Yarowia lipolytica var. BCS and Candida pseudointermedia) on the final nutritional content of hydroponic green maize fodder (Zea Zea mays L.), applied at different fodder growth stages (1. seed-seedling stage, 2. seedling-plant 20cm, 3. during all the culture). Irrespective of the fodder growth stages at which they were applied, all yeasts tested enhanced the content of raw protein, lipids, ash, moisture and energy. The percentage of electrolytes (Na, K, Cl, sulphates, Ca and Mg) showed different responses depending on the kind of yeast applied; D. hansenii exhibited the highest increment in all electrolytes, except for phosphorous. We conclude that the addition of yeasts belonging to the genera Debaryomyces, Candida and Yarowia to the irrigation solution of hydroponic systems enhances the nutrient content of green fodder. This kind of irrigation can be applied to generate high commercial value cultures in limited spaces.

La irrigación con levaduras incrementa el contenido nutricional del forraje verde hidropónico de maíz / Yeast irrigation enhances the nutritional content in hydroponic green maize fodder

El objetivo del presente estudio fue evaluar el efecto de la irrigación con las levaduras Debaryomyces hansenii var. Fabry, Yarowia lipolytica YIBCS002, Yarowia lipolytica var. BCS y Candida pseudointermedia sobre el contenido nutricional final del forraje verde hidropónico de maíz (Zea mays L. ), al ser efectuada en diferentes etapas de crecimiento de aquel (fase semilla-plántula o fase plántula-planta 20 cm), o bien durante todo el cultivo. Todas las levaduras incrementaron el contenido de proteína cruda, lípidos, cenizas, humedad y energía bruta, independientemente de la etapa de crecimiento del forraje en las que fueron aplicadas. El porcentaje de electrólitos (Na, K, Cl, sulfatos, Ca y Mg) varió en función de la levadura aplicada; D. hansenii incrementó todos los electrólitos, excepto el P. Se concluye que la adición de levaduras del género Debaryomyces, Candida y Yarowia en la solución de riego de sistemas hidropónicos mejora el contenido de nutrientes del forraje verde. Esta práctica puede contribuir a la generación de cultivos de valor comercial en espacios limitados

The objective of this study was to evaluate the effect of irrigation with yeasts (Debaryomyces hansenii var. Fabry, Yarowia lipolytica YIBCS002, Yarowia lipolytica var. BCS and Candida pseudointermedia) on the final nutritional content of hydroponic green maize fodder (Zea Zea mays L.), applied at different fodder growth stages (1. seed-seedling stage, 2. seedling-plant 20 cm, 3. during all the culture). Irrespective of the fodder growth stages at which they were applied, all yeasts tested enhanced the content of raw protein, lipids, ash, moisture and energy. The percentage of electrolytes (Na, K, Cl, sulphates, Ca and Mg) showed different responses depending on the kind of yeast applied; D. hansenii exhibited the highest increment in all electrolytes, except for phosphorous. We conclude that the addition of yeasts belonging to the genera Debaryomyces, Candida and Yarowia to the irrigation solution of hydroponic systems enhances the nutrient content of green fodder. This kind of irrigation can be applied to generate high commercial value cultures in limited spaces.

Covalently Cross-Linked Arabinoxylans Films for Debaryomyces hansenii Entrapment.

In the present study, wheat water extractable arabinoxylans (WEAX) were isolated and characterized, and their capability to form covalently cross-linked films in presence of Debaryomyces hansenii was evaluated. WEAX presented an arabinose to xylose ratio of 0.60, a ferulic acid and diferulic acid content of 2.1 and 0.04 µg∙mg(-1) WEAX, respectively and a Fourier Transform Infra-Red (FT-IR) spectrum typical of WEAX. The intrinsic viscosity and viscosimetric molecular weight values for WEAX were 3.6 dL∙g(-1) and 440 kDa, respectively. The gelation of WEAX (1% w/v) with and without D. hansenii (1 × 10(7) CFU∙cm(-2)) was rheologically investigated by small amplitude oscillatory shear. The entrapment of D. hansenii decreased gel elasticity from 1.4 to 0.3 Pa, probably by affecting the physical interactions between WEAX chains. Covalently cross-linked WEAX films containing D. hansenii were prepared by casting. Scanning electron microscopy images show that WEAX films containing D. hansenii were porous and consisted of granular-like and fibre microstructures. Average tensile strength, elongation at break and Young's modulus values dropped when D. hansenii was present in the film. Covalently cross-lined WEAX containing D. hansenii could be a suitable as a functional entrapping film.

Effects of dietary arginine on hematological parameters and innate immune function of channel catfish.

The effects of elevated dietary arginine on the hematology and immune function of juvenile channel catfish Ictalurus punctatus were evaluated by means of in vivo and in vitro experiments. Healthy juvenile channel catfish (average weight, 34.8 g) were fed casein-gelatin-based diets containing 28% crude protein and supplemented with crystalline L-arginine (ARG) at 0.5, 1, 2, or 4% of diet. An intact-protein diet containing 1.3% arginine also was included to investigate the effects of amino acid form (crystalline-free amino acids versus intact protein). Each purified diet was fed to apparent satiation to triplicate groups of fish for 6 weeks. At the end of the experimental feeding period, the fish were injected intraperitoneally with two doses (3 d apart) of 2 mg lipopolysaccharide/kg body weight. Six days after the initial injection, the fish were anesthetized and tissue samples were obtained to evaluate hematological and humoral and cellular immune parameters, including phagocytic activity of peritoneal macrophages, hemoglobin, hematocrit, mean corpuscular volume (MCV), blood cell counts, plasma protein, and hepatic superoxide dismutase activity. High dietary levels (4% ARG) resulted in significantly higher levels of hemoglobin, hematocrit, and circulating erythrocytes. Dietary ARG did not significantly affect MCV and the number of circulating leukocytes, lymphocytes, eosinophils, and monocytes. In vitro, a moderate level (2 mM) of ARG in the culture media was found to be ideal in significantly enhancing phagocytosis. This study demonstrates that some aspects of the immune system of channel catfish are sensitive to changes in dietary ARG.