Background: The hydrolysis of keratin wastes by microorganisms is considered a biotechnological alternative for
recycling and valorization through keratinolytic microorganisms. Despite their resistant structure, keratin wastes
can be efficiently degraded by various microorganisms through the secretion of keratinases,which are promising
enzymes for several applications, including detergents, fertilizers, and leather and textile industry. In an attempt
to isolate keratinolytic microorganisms that can reach commercial exploitation as keratinase producers, the
current work assesses the dynamics of keratin biodegradation by several keratinolytic fungal strains isolated
from soil. The activity of fungal strains to degrade keratin substrates was evaluated by SEM, FTRIR-ATR spectra
and TGA analysis.
Results: SEM observations offered relevant information on interactions between microorganism and structural
elements of hair strands. FTIR spectra of the bands at 1035–1075 cm
-1 assigned to sulfoxide bond appeared
because of S–S bond breaking, which demonstrated the initiation of keratin biodegradation. According to TGA,
in the second zone of thermal denaturation, where keratin degradation occurs, the highest weight loss of
71.10% was obtained for sample incubated with
Fusarium
sp. 1A.
Conclusions: Among the tested strains,
Fusarium sp. 1A was the most active organism in the degradation process
with the strongest denaturation of polypeptide chains. Because keratinolytic microorganisms and their enzymes
keratinases represent a subject of scientific and economic interest because of their capability to hydrolyze
keratin,
Fusarium sp. 1A was selected for further studies.
