Preliminary Study on Screening of High Protease Production Strain from Marine and Its Enzymology Characteristics

Abstract:

The purpose of this study is to screen high protease production strain from the squid，with generation protease hydrolysis circle and protease activity determination method. The typical strains are identified by 16S rRNA sequencing，and subject to phylogenetic analysis. Meanwhile，the properties of crude protease enzyme are researched. The results show that after screening 10 strains had a high yield protease activity，identified belong to Bacillus sp.，Providencia sp.，Pseudomonas sp.，Among them SW5 strains produced highest enzyme activity up to 257.67±2.44 U/mL，identified as Bacillus methylotrophicus. Investigation on the crude enzymology characteristics further indicate that the enzyme exhibites the highest activity at pH 8.0 and the optimum temperature is 40 ℃． The protease activity is greatly inhibited by Mn2+、Ba2+ and Ca2+，but is not inhibited by Fe2+ and Zn2+ at the final ion concentration 1 mmol/L.