FACTORS AFFECTING THE GROWTH OF FUSARIUM-PROLIFERATUM AND THE PRODUCTION OF FUMONISIN B-1 - OXYGEN AND PH

Fumonisins are mycotoxins produced primarily by Fusarium moniliforme a nd Fusarium proliferatum in corn, In liquid culture, production of fum onisin B-1 (FB1), the most common moiety of the family of fumonisins, can be obtained using a defined medium that is nitrogen-limited. Under nitrogen-limited conditions both growth and the production of FB1 wer e greatly influenced by pH and aeration, At pH above 5.0, F. prolifera tum grew normally but produced little FB1 (<100 mu g m(-1)). At pH bel ow 5.0, there was less growth but substantially more FB1. Below a pH o f 2.5, both growth and metabolism were slower with very little FB1 pro duced, When tile optimal pH range of between 3.0 and 4.0 under well-ae rated conditions was used, both growth and FB1 production were high, H owever, under oxygen-limited conditions, less growth occurred, glucose consumption was increased, and no FB1 was produced.