TITLE:
Sclerotia Formation and Toxin Production in Large Sclerotial Aspergillus flavus Isolates from Kenya
AUTHORS:
S. A. Okoth, B. Nyongesa, V. Joutsjoki, H. Korhonen, V. Ayugi, E. K. Kang’ethe
KEYWORDS:
Sclerotia, Aflatoxins, Maize, Kenya, Aspergillus flavus
JOURNAL NAME:
Advances in Microbiology,
Vol.6 No.1,
January
26,
2016
ABSTRACT: We studied the relationship between sclerotia formation and aflatoxin production
by Aspergillusflavus strains isolated
from maize kernels from Nandi County. Isolates recovered from maize kernels were
tested for their ability to form sclerotia on different growth media. PCR analysis
was done on the isolates to detect 2 structural genes, aflD and aflQ, involved in
aflatoxin biosynthesis pathway. Positive A.
flavus isolates for one or both genes were grown on Yeast Extract Sucrose Agar
medium and aflatoxins quantified using LCMSMS. All the isolates formed large sclerotia
and their formation was influenced by media type but could not be related to amount
of aflatoxins produced both in vivo and in vitro. Though sclerotia are
perennating structures and so contribute to survival index of a fungus, their initiation
is regulated by external factors though ability to form is genetic. This brings
ambiguity of their presence or abundance as a measure of toxicity.