INVESTIGADORES
DÍAZ Gabriela VerÓnica
congresos y reuniones científicas
Título:
Polyphasic identification of Aspergillus sp. LBM 134 in Misiones, Argentina
Autor/es:
ROMINA OLGA CONIGLIO; CLARA INÉS CHUNGARA; GABRIELA VERÓNICA DÍAZ; PEDRO DARÍO ZAPATA; LAURA LIDIA VILLALBA; MARÍA ISABEL FONSECA
Lugar:
Manaus
Reunión:
Congreso; IX Congresso Brasileiro de Micologia; 2019
Institución organizadora:
Societas Brasiliensis Micologiae - Instituto Nacional de Pesquizas Amazonicas
Resumen:
Aspergillus is a cosmopolitan genus of filamentous fungi which includes important species for basic research, medical mycology and industries. Species from Nigri section are known as efficient producers of extracellular enzymes that can be used on industrial application. In this sense, it is interesting to screen new isolates of species of section Nigri and identify carefully the isolates. The International Commission of Penicillium and Aspergillus recently suggested a polyphasic approach for identification of Aspergillus species. This identification integrates different types of data and information of the microorganism to obtain a consensual result.The aim of this study was to identify Aspergillus sp. LBM 134, isolated in Misiones, Argentina. The identification was performed by the online service Polyphasic Identification of the Institute of Fungal Biodiversity Westerdijk (CBS) and included molecular, macromorphological and micromorphological analysis, as well as acid production tests.Macromorphological characteristics were observed by incubating the fungus on Czapek Yeast Extract Agar (CYA), Czapek Yeast Extract NaCl (CYAS), Malt Extract Agar (MEA) and Creatine Sucrose Agar (CREA) at different temperatures for 7 d. Diameters and colors of mycelial colonies were observed and measured. Production of cyclopiazonic acid and other alkaloids that react to Ehrlich were examined using the filter paper method. Micromorphological characteristics were observed by optic microscope using the lactophenol cotton blue method and were analyzed with ImageJ 1.47v program. DNA was extracted from the mycelium grown on Yeast Extract Sucrose (YES) at 25 °C for 3 d. Molecular markers ITS, Bt, CAM, D1/D2 and Tef were amplified with ITS1-ITS4, Bt2a-Bt2b, CMD5-CMD6 and EF1S-Tef1R universal primers respectively; later they were sequenced. DNA sequences were edited with Chromas v2.6.5 and BioEdit Sequence Alignment Editor v7.0.5.LBM 134 has biseriate conidiophores, large and hyaline stipe (1000 - 1500 µm), light brown sclerotia and black globose to sub globose conidia (3 x 2.6 µm) with finely echinulate ornamentation. Also, produced acid on CREA media and did not produce alkaloids. All this information gathered to the polyphasic identification resolved that LBM 134 is A. niger. Polyphasic identification is a safe, accurate, and sensible method for the identification and differentiation of species of the genus Aspergillus.