TRANSFORMATION OF GLUCONOBACTER-OXYDANS SUBSP SUBOXYDANS BY ELECTROPORATION

An efficient electroporation system for Gluconobacter oxydans subsp. s uboxydans was developed that gave transformation frequencies of up to 10(5) transformants/mu g of DNA. The system was studied with respect t o different operating parameters including (i) the effect of electrica l conditions, i.e., field strength and resistance, (ii) DNA concentrat ion, (iii) composition of the electroporation buffer, (iv) initial cel l concentration, and (v) stage of growth of the cells. Optimal electro poration conditions were found under the following conditions: 12.5 kV /cm field strength, 400 Omega parallel resistor setting, 0.4-0.5 mu g DNA/100 mu L cell suspension, and electroporation buffer containing ME ions and >10(11) colony-forming units/mL of early to mid log phase ce lls.