ABSTRACT
The interval between subculturing, which varies between every two weeks or a month, depends on the storage conditions and on the growth rate of organisms. The bacterium can be subcultured on maintenance media especially designed to allow low growth rates and extend the culture's life. Storing cultures in a refrigerator at a temperature of 4°C, which slows growth, protects from damage due to evaporation of the medium and reserves the culture. There are several methods available for maintenance of pure cultures; the choice of the method depends upon the purpose, size of collection, and the laboratory. Plant pathogenic bacterial cultures are maintained on yeast–glucose–chalk–agar medium rather than the routinely used nutrient–sucrose–agar medium. The layer of paraffin prevents dehydration of the medium, and by ensuring anaerobic conditions, the microorganisms remain in a dormant state. Preservation of plant pathogenic bacterial cultures in edible/nonedible oils was reported from Professor Borkar’s laboratory in 2007.
