SUMMARY
The transformation and subsequent regeneration of ruminal strain
Streptococcus bovis AO24/85 protoplasts by plasmid DNA was studied.
The best stabilizer for regeneration of protoplasted cells was 5 %
of sucrose in the regeneration medium and agar plates. Optimal
concentration of PEG 6000 in the transformation medium was 25% for
both of plasmids tested. Addition of Ca2+ and Mg2+ ions (2.5
mmol.l-1) into the transformation medium increased the proportion
of regenerated cells. Transformation frequencies were 3 x 103 per
ug of pNZ12 and 2.4 x 102 transformants per ug of pJK108
respectively.
Contact: Dr. Javorsky