[Overcoming restriction of Streptomyces hygroscopicus 10-22 by the modification of S. fradiae--an attempt to develop a transformation system for S. hygroscopicus 10-22].
No transformant was obtained when pIJ702 (tsr,mel+) from S. lividans TK24 was used to transform S. hygroscopicus 10-22. pIJ702 isolated from S. fradiae ATCC 10745, however, was transformed into 10-22 at a frequency of 10(3)-10(4) transformants/micrograms DNA. Among the transformant colonies, only 1/1000 of them were black in colour (mel+) while a great majority of them remained white (mel-). Plasraid pIJ702 band was only visualized on agarose gels from the black colonies but not from the white colonies. However, when pIJ702 isolated from both black and white transformants were used to transform S. lividans TK24, the mel gene was expressed normally in the recipients. The preparations was also successful in transforming S. hygroscopicus 10-22, and again gave rise to 1/1000 of black colonies only. When the 10-22 (pIJ702) black colonies were plated on non-selective medium, among the majority of black colonies grown, there were a few white colonies, which were proved to be host mutants of 10-22. These mutants were transformable by pIJ702 and homogeneous black colonies were obtained.
Qin
Z
Z
Agricultural Antibiotics Laboratory, Huazhong Agricultural University, Wuhan.
Deng
Z
Z
Zhou
Q
Q
Chen
H
H
D009154:Mutation; D013302:Streptomyces / Q000235:genetics*; D014169:Transformation, Bacterial