Singh, R., Tyagi, P.K., Divya and Sharma, M. 2013. Ochratoxigenic potential of Aspergillus westerdijkiae NRRL 3174 under laboratory conditions. Indian Journal of Poultry Science, 48(2): 247-249.
Ochratoxin A (OTA) production by Aspergillus westerdijkiae NRRL 3174 in liquid medium (yeast extract and sucrose) and solid substrates (maize and rice) was studied under laboratory conditions. Liquid medium containing 2% yeast extract and various concentrations of sucrose (0-16%) was inoculated with fresh spores of Aspergillus westerdijkiae NRRL 3174 and incubated for 14 days at 25±0.5oC as stationary cultures. The OTA production increased with the increase in sucrose concentration up to 8%, however, above 8%, a decrease in OTA production was recorded. The highest production of OTA (21 mg/100ml) was recorded at 8% sucrose concentration containing 2% yeast extract medium. In case of solid substrates, the OTA yield increased with the increase in moisture content of the substrates from 15 to 35 percent. Considerably lower yield of OTA was recorded at 20 and 350C as compared to 25 and 300C temperatures. The highest production of OTA (0.99 g/kg maize and 0.98 g/kg rice) was harvested at 35% moisture and 300C temperature in 14 days of incubation period. It is thus concluded that fungal growth is not related to ochratoxin production and the maximum yield of OTA can be harvested at 8% sucrose and 2% yeast extract medium. Further, the maximum yield of OTA on solid substrate can be harvested at 35% moisture level and between 25 and 30oC temperature.
Key words: Ochratoxin, Aspergillus westerdijkiae, incubation period.
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