Fumarases have been successfully applied in industry for the production of L-malate. However, the industrialization of fumarases is limited by their low thermostability. In this study, the thermostability of fumarase C from Corynebacterium glutamicum was enhanced through directed evolution, simulated mutagenesis, site-directed mutagenesis and saturated mutagenesis. Mutant 2G (A411V) was initially constructed through directed evolution. Its half-life at 50 degrees C (t(1/2), (50)(degrees C)) increased from 1 min to 2.2 min, and the T-50(15) (temperature at which the activity of enzyme decreased by 50% in 15 min) increased from 44.8 degrees C to 47.2 degrees C. Besides, several different mutants were obtained by site-directed mutation. Among them, mutant 3G (A227V) showed significant improvement in thermostability with a 3.3-fold improvement of t(1/2)(,)(50)(degrees C) and a 3.6 degrees C increase in T-50(15) compared to the wild-type enzyme. Then, 2/3G (A227V, A411V) was obtained by combining the mutant 2G with the mutant 3G, for which the t(1/2)(,50 degrees C) and T-50(15) increased to more than 768 min and 52.4 degrees C, respectively. Finally, site-saturated mutagenesis was employed on amino acid residues 175-Glu, 228-Gly, 297-Gly, 320-Lys and 464-Glu to maximize the thermostability of mutant 2/3G. The most thermostable mutant 175G with amino acid substitutions (A227V, A411V, E175K) was isolated. Its t(1/2,)(50)(degrees C) increased to more than 2700 min while that of wild-type enzyme was only 1 min and T-50(15) was 9.8 degrees C higher than the wild-type enzyme. The thermostable mutated enzymes generated without affecting the activity in this study would be an attractive candidate for industrial applications.