Abstract
The main objective of the study is to characterize two new strains of Aspergillus fumigatus through morphometric, biochemical, molecular methods, and to evaluate their antimicrobial potentiality. The micro-morphotaxonomy, growth, and metabolic behavior of the strains, nHF-01 and PPR-01, were studied in different growth conditions and compared with standard strain. The molecular characterization was done by sequencing the ncrDNA ITS1-5.8S-ITS2 and D1-D2 domains of the nc 28S rDNA region and compared with a secondary structure-based phylogenetic tree. The secretory antimicrobials and pigments were characterized by TLC, UV-Vis, and FT-IR spectroscopy. Both the strains showed distinct growth patterns in different nutritional media and could assimilate a wide range of carbohydrates with distinctive biochemical properties. The molecular characterization revealed the strains, nHF-01 and PPR-01, as Aspergillus fumigatus (GenBank Accession No. MN190286 and MN190284, respectively). It was observed that the strain nHF-01 produces red to brownish pigments having mild antimicrobial activity while the strain PPR-01 does not represent such transformations. The extractable compounds had a significant antimicrobial potentiality against the human pathogenic bacteria. From this analysis, it can be concluded that the nHF-01 and PPR-01 strains are distinct from other A. fumigatus by their unique characters. Large-scale production and detailed molecular elucidation of the antimicrobial compounds may lead to the discovery of new antimicrobial compounds from these strains.