Aflatoxin production by Aspergillus flavus isolates from green– tiger shrimps (Penaeus semisulcatus)

Backgrounds and objectives: to obtain information about aflatoxigenicity of isolated aspergillus flavus strains fromshrimps.material and methods: forty – three isolates of aspergillus flavus from cultured green tiger shrimps of persian gulf wereexamined for their ability to produce aflatoxins. initially two media; aflatoxin producing ability medium and coconut agarmedium were used to detect fluorescence under uv light, later the presence of aflatoxin in culture extract was confirmed andquantified by high pressure liquid chromatography.results: only 2 (4.6%) isolates fluoresced on aflatoxin producing ability medium and coconut agar medium under uvlight. in sum, 9 (20.93%) isolates (including the 2 above mentioned isolates) were confirmed to be aflatoxigenic by highperformance liquid chromatography. eight (18.7%) of isolates produced aflatoxin b1 ranging from 0.32 to 12.18 ppb, while1(2.3%) of isolates produced 18.88 ppb and 0.36 ppb of aflatoxin b1 and aflatoxin b2 respectively. aspergillus oryzae did notproduce any detectable aflatoxins. although highest level of aflatoxin b1 (18.88 ppb) was detected in an isolate from a hepatopancreaticsample, no histopathological change was observed in that tissue.conclusion: some aspergillus flavus strains which were isolated from shrimps showed aflatoxin producing ability withoutany histopathological changes in tissues of contaminated shrimps.