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Hydrolytic enzymes secreted by Paecilomyces lilacinus cultured on sclerotia of Aspergillus flavus

Permanent URL:
http://handle.nal.usda.gov/10113/25102
File:
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Abstract:
Sclerotia, the survival stage of Aspergillus flavus, are compact masses of mycelia capable of withstanding harsh climatic conditions. Six strains of Paecilomyces lilacinus, originally isolated from sclerotia of A. flavus var. flavus or A. flavus var. parasiticus, were also able to colonize the sclerotia from four different strains of A. flavus under laboratory conditions. P. lilacinus strains did not differ significantly in their colonization ability, but host susceptibility appeared to be an important factor. P. lilacinus strains were cultured in vitro for 96 h on a basal salt medium containing either ground sclerotia of A. flavus or glucose plus asparagine. Activities of hydrolytic enzymes such as polysaccharidases, proteases, and chitinases were determined in the culture supernatants. Supernatants from fungal cultures grown in the basal medium containing glucose plus asparagine medium showed very little or no enzyme activity, whereas fungi grown on ground sclerotia produced a variety of enzymes. Specifically, all strains produced chitinases (endochitinase and N-acetyl glucosaminidase), beta-1,3-glucanase, chymoelastase and chymotrypsin, suggesting that these enzymes may be required for colonization of sclerotia. Production of beta-1,4-glucanase, dextranase, cellulase, and trypsin was strain variable, suggesting that these enzymes may not be required.
Author(s):
Gupta, S.C. , Leathers, T.D. , Wicklow, D.T.
Subject(s):
Aspergillus flavus , Paecilomyces lilacinus , enzyme activity
Format:
p. 99-103.
Note:
Includes references
Source:
Applied microbiology and biotechnology Apr 1993. v. 39 (1)
Language:
English
Year:
1993
Collection:
Journal Articles, USDA Authors, Peer-Reviewed
Rights:
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.