Changes in pyruvate and ascorbate production and antioxidant enzyme activities together with lipid peroxidation levels in Fusarium equiseti were investigated in relation to changes in the concentrations of glucose and maltose as carbon sources in the range of 5-25 g/l in Armstrong Fusarium Medium (AFM). The highest pyruvate concentration obtained at 20 g/l maltose was 67.5 +/- 0.69 mug/ml while ascorbic acid reached a maximum value at 25 g/l glucose of 1866 +/- 26.1 mug/ml The maximum superoxide dismutas (SOD) activities related to increased pyruvate production were determined in AFM medium containing 20 g/l glucose as 41.49 +/- 0.65 and maltose as 61.12 +/- 0.8 IU/mg. Catalase (CAT) activity variations showed coherence with SOD activity in a medium containing maltose and reached 219.11 +/- 2.8 IU/mg while they were decreased with increasing glucose concentration. glutathione peroxidase (GSH-Px) activities in E equiseti did not change significantly with glucose and maltose concentration and were determined to be 1.21 +/- 0.22 and 1.67 +/- 0.15 IU/mg, respectively. Minimum lipid peroxidation levels for each carbon source were determined in both 20 g/l maltose and glucose concentrations as 0.9 and 1.62 nmol MDA/g wet weight. (C) 2003 Elsevier Ltd. All rights reserved.