Abstract:An agarase-producing strain with high initial enzyme was isolated from Taisui. The strain was identified as Paenibacillus after morphological and molecular biological analysis and named Paenibacillus sp. P1(abbreviated as P1). The strain P1 which had a rod-shaped cell was a Gram-negative bacterium. And it could not hydrolyze gelatin or cellulose. The optimum fermentation time of strain P1 was 40 h based on the study of the growth and enzyme production of strain P1. Single factor experiment was used to optimize the fermentation medium.The optimal medium for agarase production from P1 strain were Agar 3 g/L, peptone 2 g/L,K2HPO4·3H2O 1.0 g/L, NaCl 0.3 g/L, MgSO4·7H2O 0.05 g/L, FeSO4·3H2O 0.02 g/L, and CaCl2 0.04 g/L. The strain P1 was fermented in the optimized medium for 40 h and the agarose activity was 3.47×104 U/L after optimization, which was 3.4 times higher than that before optimization. The results lay a foundation for the screening of agarose-producing strains from non-marine sources and the scale-up fermentation of agarose.
