Figure 4.

CuSO₄ lowers conjugation efficiency when present during mating. ‘Donor’/’Recipient’: the donor (HA14) or recipient strain (HA4) was grown to log phase while exposed to 3 mM CuSO₄, after which the culture was pelleted and resuspended in fresh LB, mixed with untreated donor or recipient, and allowed to mate in the absence of CuSO₄. ‘Mating’: the donor and recipient strains were grown to log phase in the absence of CuSO₄, and then allowed to mate in the presence of 3 mM CuSO₄. The bars represent the mean conjugation efficiency relative to the control (0 mM), and the error bars represent the standard error of the mean (SEM) of 2 biological replicates with 2 technical replicates each.