title: Effect of Ca2+ ions on plasmid transformation of Streptococcus lactis protoplasts.
abstract: The effects of Mg2+ and Ca2+ ions on the efficiency of the plasmid transformation of lysozyme-treated Streptococcus lactis protoplasts were compared. A 33-megadalton plasmid, pLP712, coding for lactose fermentation and a 6.5-megadalton plasmid, pGB301, coding for erythromycin and chloramphenicol resistance were used as model plasmids, and S. lactis MG1614 was the recipient. Replacing Mg2+ with Ca2+ in the transformation buffer was found to increase transformant frequency more than 10-fold with both plasmids.
mesh_terms: D002118:Calcium / Q000494:pharmacology*; D005285:Fermentation; D013294:Lactococcus lactis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D007785:Lactose / Q000378:metabolism; D008274:Magnesium / Q000494:pharmacology; D010957:Plasmids / Q000187:drug effects*; D011523:Protoplasts / Q000187:drug effects / Q000502:physiology; D014169:Transformation, Bacterial / Q000187:drug effects*
chemical_list: D008274:Magnesium; D007785:Lactose; D002118:Calcium