The principal aim of this study was to estimate the formation of fumonisins (FB(1) and FB(2)), moniliformin (MON), and ergosterol (ERG) by Fusarium oxysporum and Fusarium proliferatum, while the formation of beauvericin (BEA) was estimated by the latter Fusarium species only. Moreover, the effect of temperature on the biosynthesis of mycotoxins was also evaluated. Fumonisins were formed by F. proliferatum, with the highest yield at 18 degrees C (720.0-1976.6 microg g(-1) for FB(1), 74.2-670.8 microg g(-1) for FB(2)) and only by three of four F. oxysporum strains at a very low level (0.02-4.77 microg g(-1) for FB(1), 0.02-2.15 microg g(-1) for FB(2)). The amount of MON formed by F. proliferatum was the highest (p < 0.001) at 32 degrees C (3056.87 microg g(-1)), while MON biosynthesis by F. oxysporum was lower 227.54 microg g(-1) (p < 0.001). BEA was produced by F. proliferatum with the highest level at 25 degrees C (p < 0.001). ERG-recognized as an indicator of fungal biomass development and as a consequence of mycotoxin formation-was found at the highest concentration at a biosynthesis temperature of 25 degrees C for F. proliferatum and F. oxysporum (p < 0.001).