A Study on Strain Degeneration and Its Control of Bacillus subtilis

The degeneration of 2 strain (BS-3 and PRS5) in various media and subculturing was studied with the decrease of antagonism and biomass of Bacillus subtilis as the degeneration's token, and then effects of 5 carriers and rejuvenescert time on the restoration of the biomass and antagonism for B. subtilis were also explored.Of the seven regular media, B. subtilis most stably grew on SDAY, but those nutrition poor ones such as PDA, WPD, CMA caused degeneration frequently, the degeneration's rate of BS-3 was slower than that of PRS5.Among 5 rejuvenescent carriers, the carrier which contained steriled soil, 1% peptone, 1% glucose and 0.5% yeast abstract was regarded as the best one.In rejuvenescent rate, PRS5 was 90 days and 120 days faster than BS-3 respectively.