Article

Two different proteases produced by a deep-sea psychrotrophic bacterial strain, Pseudoaltermonas sp. SM9913

Marine Biology (impact factor: 2.28). 10/2003; 143(5):989-993. DOI:10.1007/s00227-003-1128-2 pp.989-993

ABSTRACT A psychrotrophic bacterial strain, Pseudoaltermonas sp. SM9913, was isolated from deep-sea sediment collected at 1,855m depth. Two proteases produced by Pseudoaltermonas sp. SM9913 were purified, MPC-01 and MCP-02. MCP-01 is a serine protease with a molecular weight of 60.7kDa. It is cold-adapted with an optimum temperature of 30–35C. Its Km and Ea for the hydrolysis of casein were 0.18% and 39.1kJ mol–1, respectively. It had low thermostability, and its activity was reduced by 73% after incubation at 40C for 10min. MCP-02 is a mesophilic metalloprotease with a molecular weight of 36kDa. Its optimum temperature for the hydrolysis of casein was 50–55C. The Km and Ea of MCP-02 for the hydrolysis of casein were 0.36% and 59.3kJ mol–1, respectively. MCP-02 had high thermostability, and its activity was reduced by only 30.5% after incubation at 60C for 10min. At low temperatures, Pseudoaltermonas sp. SM9913 mainly produced the psychrophilic protease MCP-01.

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Keywords

casein
 
deep-sea sediment
 
Ea
 
low temperatures
 
mesophilic metalloprotease
 
molecular weight
 
optimum temperature
 
proteases
 
Pseudoaltermonas sp
 
psychrophilic protease MCP-01
 
psychrotrophic bacterial strain
 
serine protease