Briefly, following the
inoculation of stationary culture into LB at 0.5%, the 2-h cultures
of both donor (0.15 ml) and recipient cells (0.15 ml) were mixed
and incubated for 15 min at 37 °C without shaking. After
spreading 0.1 ml of the aliquots onto antibiotic medium 3 plates
containing the appropriate antibiotics, the plateswere incubated at
37 °C to select transcipients.