Production of Aflatoxin on Rice

TLDR

Aflatoxin B1 was isolated from impurities and other aflatoxins by silica‑gel chromatography using 1 % ethyl alcohol in chloroform, then recrystallized from chloroform‑hexane mixtures to achieve analytical purity. The developed method produced aflatoxin on rice, yielding more than 1 mg B1 per gram of substrate in 5 days at 28 °C, with a crude product comprising 50 % aflatoxin (B1:B2:G1:G2 = 100:0.15:0.22:0.02) isolated by chloroform extraction and hexane precipitation.

Abstract

A method has been developed for the production of aflatoxin by growing Aspergillus flavus strain NRRL 2999 on the solid substrate rice. Optimal yields, more than 1 mg of aflatoxin B1 per g of starting material, were obtained in 5 days at 28 C. A crude product containing aflatoxins was isolated by chloroform extraction and precipitation with hexane from concentrated solutions. The crude product consisted of 50% aflatoxin in the following ratio: B1-B2-G1-G2, 100:0.15:0.22:0.02. Aflatoxin B1 was separated from almost all the impurities and from the other aflatoxins by chromatography on silica gel with 1% ethyl alcohol in chloroform. Analytically pure aflatoxin B1 was recrystallized from chloroform-hexane mixtures.