Molecular identification of Brazilian Fusarium strains: sources of proteases with milk-clotting properties

Braz J Microbiol. 2023 Sep;54(3):1665-1674. doi: 10.1007/s42770-023-01016-z. Epub 2023 Jun 2.

Abstract

Fusarium is a genus of ubiquitous fungi that comprises mycotoxigenic animal and plant pathogens. These fungi have the ability to exploit a wide range of substrates and hosts, indicating their great potential for enzyme production; however, this aspect is understudied. Therefore, the present study aimed for revaluating the identity of twenty-three Fusarium strains maintained in the University Recife Mycology (URM) culture collection, Brazil, and to evaluate their potential for proteases production and the milk-clotting activity of these proteases. According to phylogenetic analysis of translation elongation factor 1-alpha (TEF1) gene partial sequences, these strains belonged to 12 species representing four species complexes: Fusarium concolor, F. fujikuroi, F. incarnatum-equiseti, and F. oxysporum. Four of these species are putatively novel to science. Notably, novel associations of Fusarium spp. with certain hosts/substrates were documented. The proteolytic activity ranged from 1.67 U ml-1 to 22.03 U ml-1 among the evaluated fungal isolates, with specific proteolytic activity reaching 205.86 U mg-1. The values for coagulant activity and specific activity were up to 157.14 U ml-1 and 1,424.11 U mg-1, respectively. These results indicate the potential of URM Fusarium strains as a source for the production of enzymes of industrial interest. Additionally, they reinforce the importance of applying DNA-based methods for reviewing the identification of fungal strains preserved in biodiversity repositories.

Keywords: Brazilian fungi; Culture collection; Fusarium phylogeny; Milk-clotting; Proteolytic activity.

MeSH terms

  • Animals
  • Brazil
  • Fusarium* / genetics
  • Milk
  • Peptide Hydrolases / genetics
  • Phylogeny

Substances

  • Peptide Hydrolases