Comparison of microscopic, macromorphological and aflatoxin producing capabilities of Aspergillus species associated with rhizosphere of groundnut (A. hypogaea L.)
Manjusha Chakranarayan*and Anita Pati
Journal Title:Journal of Chemical, Biological and physical sciences
The role of laboratory in the identification has gained greater attention as
the incidence of fungal infection is increased. The objective of the study was to
isolate the aflatoxin producing Aspergillus species from the rhizosphere of groundnut.
Identification of the Aspergillus species was done on the basis of morphological
methods including; microscopic and macroscopic characteristics. Ten standard
species of Aspergillus namely A. flavus, A. parasiticus, A. niger, A. repens, A.
fumigatus, A. kanagawaensis, A. ochraceus, A. sydowi, A. terreus and A. nidulans and
were isolated and characterized. Rapid detection of aflatoxin production was carried
out by using coconut agar medium. The colonies were detected under long-wave UV
light by the blue-green fluorescence on the reverse side after 2 to 5 days of growth.
Further the aflatoxin production capacity was screened using thin layer
chromatographic technique. Depending upon the intensity of bands on TLC plates A.
flavus and A. parasiticus were found to be highly aflatoxigenic and produce aflatoxin
B1 on Richard liquid medium in the range of 966.66-266.66 ?g/kg respectively.
Quantitation of aflatoxin was done by using quantitative TLC, which was based on
the comparison of the fluorescent intensity of the sample spot with standard spot.
While all the other species are non-aflatoxigenic strains.