Succinate does not support the growth of the tat deletion strains. The strains were initially cultured in 7H9-ADC medium, and the cells were harvested, washed, and diluted into M63-succinate medium. Growth was monitored by measuring the change in OD600 values over time. The symbols for each strain are as follows: x, wild type; open symbols, tat deletion strains; closed symbols, complemented strains.