Bioprospecção enzimática de fungos dos gêneros Aspergillus spp., Talaromyces spp. e Penicillium Spp. do bioma caatinga

Abstract

The Caatinga biome is an exclusively Brazilian semi-arid ecosystem characterized by extreme environmental conditions that favor the establishment of metabolically versatile and well-adapted microbial communities. Despite its ecological importance, the diversity of soil filamentous fungi in this biome remains poorly explored. Therefore, this study aimed to evaluate the diversity of filamentous fungi belonging to the genera Aspergillus, Penicillium, and Talaromyces in native and banana-cultivated soils from the Caatinga biome, as well as to investigate their biotechnological potential through chitinolytic activity. Ten soil samples were collected in Jaíba, Minas Gerais, Brazil, including five from native vegetation and five from banana cultivation areas. Fungal isolation was performed using serial dilution on DRBC and DG18 media, followed by morphological identification and functional screening. A total of 587 fungal isolates were obtained, of which 102 belonged to the target genera. Fungal density ranged from 2.64 to 4.14 log CFU/g, with no statistically significant difference between land-use systems (p > 0.05), although cultivated soil showed greater variability among sampling points. Chitinolytic activity varied widely among isolates, ranging from 0.043 to 0.140 U/mL, with significant differences between isolates (p < 0.001) and the formation of four distinct groups according to the Scott-Knott test. Isolates from native soil were more frequently associated with higher enzymatic activity groups, although highly active isolates were also detected in cultivated soil. This variability is associated with genetic diversity and differential regulation of chitinase- encoding genes. These findings demonstrate that Caatinga soils represent important reservoirs of filamentous fungi with relevant functional diversity, contributing to the understanding of microbial biodiversity in this biome and highlighting its potential as a source of biotechnological resources, in accordance with Sustainable Development Goal 15 (Life on Land). Keywords: biotechnological potential, chitinolytic activity; filamentous fungi; soil microbiota; tropical soils.