Abstract:A total of 10 protease-producing strains were isolated from homemade fermented seafoods, and were identified as Bacillus velezensis S1YBB, S1YB, Serratia marcescens S2DD, S2DB, C2Y3, M1B, C2J2, Micrococcus luteus C1Y1, Shewanella alga C2J1, and Enterococcus hirae M1R. The biological and enzymatic characteristics of S1YB, S2DB, C1Y1, C2J1, and M1R from different species with relatively higher enzyme activities were evaluated. The optimum growth temperature, pH and salinity of the strains were 37 ℃, 6.0, and 20 g/L, respectively. The optimum temperature and pH for the enzyme activities were 50 ℃ and 6.0-8.0, respectively. Relative enzyme activities of the strains were decreased under the treatment of Na+, K+, Ca2+, Fe2+, Fe3+, Zn2+, Cu2+ and ethylene diamine tetraacetic acid (EDTA) and in response to their concentrations. The results provided theoretical supports for exploring strains with excellent fermentation performance in seafood fermentation and controlling unexpected protease-producing strains in seafood fermentation processes.