Potencial de los hongos anamorfos de Guatemala para la producción de α-amilasas utilizando como sustrato cascarilla de arroz / Guatemalan anamorphic fungi and their potential use in production of α-amylases using rice husk as a substrate

Los desechos agroindustriales se generan en grandes cantidades, y en la mayoría de los casos son depositados en vertederos lo cual constituye un problema ambiental. Estos residuos lignocelulósicos pueden utilizarse como materia prima o sustrato de crecimiento de hongos anamorfos, que a través de procesos de fermentación pueden producir biocombustibles, enzimas, vitaminas, antioxidantes, alimentos para animales, antibióticos y otros productos químicos. En este estudio se determinó la capacidad de producción de α-amilasas de 20 cepas nativas de hongos anamorfos del cepario de hongos del Departamento de Microbiología, Facultad de Ciencias Químicas y Farmacia, de la USAC a través de fermentación en estado sólido, utilizando como sustrato cascarilla de arroz. La extracción de las enzimas se realizó por microfiltración y la actividad amilolítica fue medida por espectrofotometría. De las cepas evaluadas se encontró que las amilasas de Aspergillus sp. SL15319 mostraron la mayor actividad media (desviación estándar), tanto libres, 930.26 (1.56) UA/dl, como inmovilizadas, 900.34 (3.21) UA/dl, seguido por las de Beltrania rhombica, 905.02 (10.72) y 879.07 (3.87) UA/dl y Aspergillus sp. SL15119, 907.46 (5.17) y 875.95 (9.39) UA/dl (p < .05). La importancia de este estudio radica en dar a conocer el potencial de los hongos anamorfos nativos de Guatemala para el aprovechamiento de los residuos agroindustriales como materia prima para la producción de sustancias de utilidad para el ser humano, y en la reducción de la carga contaminante que se desecha al medio ambiente.

Agroindustrial wastes are generated in large quantities and in most cases deposited in landfills as waste. These lignocellulosic residues can be raw material or substrate for anamorphic fungi, which through fermentation processes can produce biofuels, enzymes, vitamins, antioxidants, animal feed, antibiotics and other chemical products. In this study, the α-amylase production capacity of 20 native strains of anamorphic fungi from the fungal strain collection of Departamento de Microbiología, Facultad de Ciencias Químicas y Farmacia, USAC was determined through solid state fermentation, using rice husk as a substrate. The extraction of the enzymes was carried out by microfiltration and the amylolytic activity was measured by spectrophotometry. Of the strains evaluated, it was found that the amylases of Aspergillus sp. SL15319 showed the highest mean activity (standard deviation), both free, 930.26 (1.56) UA/dl, and immobilized, 900.34 (3.21) UA/dl, followed by those of Beltrania rhombica, 905.02 (10.72) and 879.07 (3.87) UA/dl and Aspergillus sp. SL15119 907.46 (5.17) and 875.95 (9.39) UA/dl (p < .05). The importance of this study lies in making known the potential of native anamorphic fungi in Guatemala for the use of agro-industrial waste as a raw material for the production of substances of use to humans, and in reducing the pollutant load that is discharged into the environment.

Diagnosis and Management of Grain-Induced Asthma

Grain-induced asthma is a frequent occupational allergic disease mainly caused by inhalation of cereal flour or powder. The main professions affected are bakers, confectioners, pastry factory workers, millers, farmers, and cereal handlers. This disorder is usually due to an IgE-mediated allergic response to inhalation of cereal flour proteins. The major causative allergens of grain-related asthma are proteins derived from wheat, rye and barley flour, although baking additives, such as fungal alpha-amylase are also important. This review deals with the current diagnosis and treatment of grain-induced asthma, emphasizing the role of cereal allergens as molecular tools to enhance diagnosis and management of this disorder. Asthma-like symptoms caused by endotoxin exposure among grain workers are beyond the scope of this review. Progress is being made in the characterization of grain and bakery allergens, particularly cereal-derived allergens, as well as in the standardization of allergy tests. Salt-soluble proteins (albumins plus globulins), particularly members of the alpha-amylase/trypsin inhibitor family, thioredoxins, peroxidase, lipid transfer protein and other soluble enzymes show the strongest IgE reactivities in wheat flour. In addition, prolamins (not extractable by salt solutions) have also been claimed as potential allergens. However, the large variability of IgE-binding patterns of cereal proteins among patients with grain-induced asthma, together with the great differences in the concentrations of potential allergens observed in commercial cereal extracts used for diagnosis, highlight the necessity to standardize and improve the diagnostic tools. Removal from exposure to the offending agents is the cornerstone of the management of grain-induced asthma. The availability of purified allergens should be very helpful for a more refined diagnosis, and new immunomodulatory treatments, including allergen immunotherapy and biological drugs, should aid in the management of patients with this disorder.

Diagnosis and Management of Grain-Induced Asthma

Grain-induced asthma is a frequent occupational allergic disease mainly caused by inhalation of cereal flour or powder. The main professions affected are bakers, confectioners, pastry factory workers, millers, farmers, and cereal handlers. This disorder is usually due to an IgE-mediated allergic response to inhalation of cereal flour proteins. The major causative allergens of grain-related asthma are proteins derived from wheat, rye and barley flour, although baking additives, such as fungal alpha-amylase are also important. This review deals with the current diagnosis and treatment of grain-induced asthma, emphasizing the role of cereal allergens as molecular tools to enhance diagnosis and management of this disorder. Asthma-like symptoms caused by endotoxin exposure among grain workers are beyond the scope of this review. Progress is being made in the characterization of grain and bakery allergens, particularly cereal-derived allergens, as well as in the standardization of allergy tests. Salt-soluble proteins (albumins plus globulins), particularly members of the alpha-amylase/trypsin inhibitor family, thioredoxins, peroxidase, lipid transfer protein and other soluble enzymes show the strongest IgE reactivities in wheat flour. In addition, prolamins (not extractable by salt solutions) have also been claimed as potential allergens. However, the large variability of IgE-binding patterns of cereal proteins among patients with grain-induced asthma, together with the great differences in the concentrations of potential allergens observed in commercial cereal extracts used for diagnosis, highlight the necessity to standardize and improve the diagnostic tools. Removal from exposure to the offending agents is the cornerstone of the management of grain-induced asthma. The availability of purified allergens should be very helpful for a more refined diagnosis, and new immunomodulatory treatments, including allergen immunotherapy and biological drugs, should aid in the management of patients with this disorder.