Abstract: The medium and fermentation conditions for levan production by Bacillus licheniformis 8-37-0-1 were optimized by single factor and orthogonal array experiments. After culture at 30 ℃ for 24 h in a medium prepared with tap water consisting of sucrose 100 g/L, yeast extract 0.6 g/L, beef extract 1.0 g/L, KH2PO4 3.0 g/L, K2HPO4 3.0 g/L, NaCl 1.0 g/L, MgSO4·7H2O 0.2 g/L and FeSO4·7H2O 0.001 g/L, a maximum levan production of 41.7 g/L was achieved, which was 5.0 times higher than before optimization.

Key words: Bacillus licheniformis 8-37-0-1, levan, fermentation condition, optimization