Abstract：To speed up the pace of industrial application of cellulose, and solve the low yield, high production cost issues in fermentation industry, orthogonal design methodology was applied to optimize the fermentation of Bacillus megaterium genetic engineering bacteria for neutral cellulase. Results indicated that optimal medium compositions were 2.5% wheat bran, 1.5% corn thick liquid, 0.75% KH2PO4, 0.04% MgSO4, and 0.25% NaCl; The optimal fermentation conditions were fermentation temperature of 37℃, pH 7.0, tank pressure 0.03~0.05 Mpa, rotation speed of shaker 600 r/min, 3 L of packing volume, 10% inoculation amount, fed 10 h xylose by 0.25 g/L/h flow rate after 4 h cultured, constant dissolved oxygen fed-batch 8 h after 16 h of fermentation, dissolved oxygen≥30% during the fermentation process. The activity of neutral cellulase obtained at this optimal fermentation condition was 3 846.48 U/mL, which was 4.3 times of the shaking flask culture. This research can provide the basis for the cellulase manufacture.
