Diversidade e potencial para a produção de enzimas de Penicillium, Aspergillus, Talaromyces e Paecilomyces isolados de solo de Mata Atlântica do Quadrilátero Ferrífero

Abstract

Brazil is a rich country in biodiversity, with numerous plants, animals and microorganisms species, distributed in different biomes, presented as an important source of biological products of interest to pharmaceutical, agricultural and food industries. The knowledge on these organisms and on the compounds produced by them still little explored, so it is important the development of biodiversity surveys, enabling the effective use of these compounds. The aim of the present study was to carry out a biodiversity survey on genera of filamentous fungi Aspergillus, Penicillium, Talaromyces, and Paecilomyces in Atlantic Forest soil located in the Quadrilátero Ferrífero, and evaluate their enzyme production potential. The isolates were morphologically characterized and evaluated according to macroscopic and microscopic aspects. The toxin production evaluation (citrinin, aflatoxins and ochratoxin A) was applied to aid in the identification of isolates by thin layer chromatography method, in addition, the protein profile of some isolates were evaluated by MALDI-TOF MS. In vitro enzyme production tests was performed screening the isolates for lipase, cellulase and pectinase enzymes, so the enzymatic index of each fungus was calculated. From the screening, one morphotype and one enzyme were selected and tested in submerged fermentation. In total, 2035 fungal isolates were obtained, among which 37 of the genus Aspergillus, 34 of Paecilomyces, 6 of Talaromyces and 1958 isolates of the genus Penicillium. Through morphological characterization was possible to identify 34 isolates of Aspergillus, 50 of Penicillium and 6 of Talaromyces, grouped into 3, 15 and 3 species, respectively. All further isolates were grouped by their morphological similarities, characterized and stored for later genetic analysis. The aflatoxin test was efficient to assist with the identification of A. flavus and A. parasiticus, thus it was able to indicate 19 isolates from the first specie and 2 from the second. The application of MALDI-TOF technique was efficient in the aid to identify the filamentous fungi, resulting in good clusters and decreasing the number of isolates to be subjected to further analysis. In the enzyme production tests, the pectinase enzyme showed the higher number of isolates producers, and the morphotype P51showed the highest enzymatic index, so it was selected for the submerged fermentation. The isolated demonstrated to be a good exo-polygalacturonase producer and optimum time, temperature and pH ranges were defined for its production. The results showed wide diversity of species in the evaluated soil, with the possibility of new species that have not been described before, besides the untapped biotechnological potential that can be better studied and used in several production processes.