Avaliação da produção de amilase e protease por fungos filamentosos de solos no Semiárido pernambucano

Abstract

The fungal soil communities suffer both quantitative and diversity interference caused by biotic and abiotic factors, and in the case of semi-arid soils, they are subject to low water availability, high temperatures and high solar radiation influences directly on the soil. development of these microorganisms. Thus, the objective of this work was to isolate and evaluate the enzymatic activity (amylase and protease) of filamentous fungi of Pernambucano semiarid soils collected at different times in the Mata da Pimenteira State Park Conservation Unit, in the municipality of Serra Talhada - PE. Soil collections were performed in August 2018 and April 2019, at three random points. Isolation of the fungi was performed by serial dilution technique using the Potato Dextrose Agar (BDA) and Sabouraud Agar (SAB) culture media added with chloramphenicol (for the inhibition of bacterial growth) in Petri dishes and incubated at room temperature. environment for seven days. After this period, the fungal colonies were quantified and, based on their morphotype, some were selected for the enzymatic tests of protease and amylase activity. As a result, 43 fungal colonies were isolated and a (CFU / g) quantification of (repeat 1), (repeat 2), (repeat 3) in BDA and SAB culture media, respectively, in the dry season and and (repeat 1), and (repeat 2), (repeat 3) in the BDA and SAB media respectively in the rainy season. Regarding the enzymatic potential 18 isolates were good producers of amylase and protease with emphasis on D8 identified as Aspergillus sp. which obtained greater degradation halos for both amylase and protease, with averages of 3.5 and 3.93 cm, respectively; and I3 also identified as Aspergillus sp. had a larger degradation halo for protease with 5.6 cm, both obtained during the drought period. In the rainy season, I9 (Isolated 4) and D9 (Aspergillus sp.) Stood out, which showed degradation halos of 3.5 and 4.16 cm for amylase and protease, respectively. The isolated fungi in this work have biotechnological importance, emphasizing how necessary is the preservation of habitats for the maintenance of microbial species associated with them.