Dr. Elizabeth Mllewskl 
Page 2 
March 25, 1981 
Dr. Dean request the following changes: 
1) Any Bacillus subtilis strain which does not revert to spore 
formation with a frequency greater than 10”^ can be used with 
indigenous vectors for cloning DNA from any non-prohibited 
source under conditions to be specified for Z. coli K-12 and 
Saccharomyces cerevisae host vector systems. 
2) Bacillus subtilis strains that do not carry an asporogenic 
mutation can be used with indigenous vectors for the cloning 
of DNA from CDC Class 1 organisms under P2 condition (Action 
Under the Guildlines , Appendix D) . 
3) Bacillus subtilis strains that do not carry an asporogenic 
mutation can be used with indigenous vectors for the cloning 
of DNA from any Bacillus sp . of CDC Class 1 under PI conditions 
(Action Under the Guildlines, Appendix D) . 
(5751 
I’ 
