Abstract:

The aim was to obtain strain producing high protease and apply it in aquiculture widely. A protease producing marine strain ZR-Pw was isolated from Jiaozhou Bay in Qingdao. The strains were identified by colony morphology, morphological characteristics, Gram staining and partial 16S rDNA gene sequence. It was added into fermentation culture medium. Then time course of growth and time course of protease activity were determined. Optimum temperature and pH were determined. The results showed that strain ZR-Pw was a member of Bacillus licheniformis. When ZR-Pw was cultured for 18 h, bacteria growth mass reached the maximum. When ZR-Pw was cultured for 24 h, yield of enzyme reached the maximum. The maximum protease activity was reached at 35℃ and pH 8.0. The experiments could provided basis for applying the strain producing protease in the production.