Study On The Low-temperature Superoxide Dismutase And Habitat Adaptation Of Antarctic Psychrophile Marinomonas Sp. NJ522

The extreme microorganism can survive in extreme environment after long period of adaptation to extreme environment, and becomes one of hot research field at present. It is of not only greatly theoretical value to understanding life extreme, evolution and classification of microorganism by studying on extreme microorganism, but also important practical value to environment pollution, ecology and exploitation of new function of microorganism. In the last few years, increased attention has been focused on the low temperature biocatalysis and environment adaptation of Antarctic microorganism. Superoxide dismutases (SOD) represent one of the main components of the antioxidant defense system (ADS). These enzymes act to disproportionate two molecules of superoxide anion to hydrogen peroxide and water, and plays important role in extreme environment adaptation of Antarctic microorganism. The study of cold-active enzymes from Antarctic bacterial increased lately.In this study, Antarctic psychrophilic bacterium M. sp. NJ522 was screened as a producer of cold-active SOD, and the optimization culture of M. sp. NJ522 producing SOD was investigated. SOD of M. sp. NJ522 was purified, and its characters were elucidated as well. The M. sp. NJ522 habitat adaptation was studied in aspects of biochemistry compositions (fatty acids and protein) and antioxidant enzymes. These results not only provided new sources of SOD, but also made the adaptation mechanism of psychrophilic clarified more all-around than before.(1) Four SOD high-producting bacteria NJ62, NJ379, NJ522 and NJ548 were selected from 421 Antarctic strains by their SOD activities and biomasses. Their optimum grow temperatures were about 10~15℃, and they could grow at 0℃. They belong to psychrophile and their SOD were cold-active enzymes. All of four strains only contained one kind of SOD isoenzymes. The SOD of NJ62 is Mn-SOD, while...