Physico-chemical parameters influencing DNase activity of the cysnobacterium Spirulina platensis

摘要

The effects of temperature, Mg~(2+), EDTA concentration and rinsing on extra- and intracellular DNase activity of Spirulina platensis strain SSP-14, were investigated. The results indicate that the tested strain contains very high extra- and intracellular DNase activity, which actually hinders the transfer of foreign geneis) to S. platensis, a cyanobacterium with multiple economic potentials. The extracellular DNase activity could easily be removed by rinsing the cells with Zarrouk medium more than once. The intracellular DNase activity could also be inhibited by ( 1 ) removal of Mg~(2+), (2) maintaining EDTA concentration above 1 mmol l~(-1), and (3) manipulating below 0-4 deg C, during all the incubation procedures. We suggest that, by using one or more of, or combining, all those experimental conditions, the chances of foreign DNA attempted to be introduced into S. platensis without being digested would be increased.