Not more than three months..

Thank you! :D 

short- term storage ,  just for one month .

The best is to keep the strain on a slope of non selective solid agar medium in a closed tube. After 3 months you will have to make a new subculture.

Best wishes 

-70 for a year

Slants (TSIA) in screw capped tubes will keep MO for longer periods than in plates. However, my experience is that you should subculture it every 2 weeks. Best wishes