Y. Tokuda et al., CHARACTERISTICS OF PLASMID STABILITY IN BACILLUS-SUBTILIS NB22, AN ANTIFUNGAL-ANTIBIOTIC ITURIN PRODUCER, Journal of fermentation and bioengineering, 75(4), 1993, pp. 319-321
The stability of plasmids pC194 and pUB110 was investigated in an anti
fungal antibiotic iturin producer, Bacillus subtilis NB22. Although pl
asmid pC194 was maintained stably over a hundred generations in five s
uccesive cultivations in iturin-production no. 3 medium, significant c
uring was observed when the cultivation was prolonged for 10 d in the
same medium. When the transformant of pC194 was cultivated in Schaeffe
r's sporulation medium, drastic curing took place in accordance with t
he occurrence of sporulation, even in the presence of an antibiotic fo
r selective pressure. In the case of pUB110, in sharp contrast to the
result with pC194, high stability was observed in the sporulation medi
um, but significant curing was observed during prolonged incubation in
no. 3 medium.