Figure 1. The growth and survival of Mycobacterium smegmatis in the presence and absences of hydrogenases.

(A) Growth of M. smegmatis mc²155 and hyd mutants into carbon-limitation. (B) Survival of M. smegmatis mc²155 and hyd mutants during carbon-limitation. The strains were grown in aerated conical flasks on HdB minimal medium supplemented with 22 mM glycerol. Growth is shown in OD₆₀₀. Survival is shown in percentage colony forming units relative to day four. Legend: Blue circles/bars = Wild-type; Red squares/bars = Δhyd123; Orange point-up triangles/bars = Δhyd1; and Purple point-down triangles/bars = Δhyd2. Error bars show standard deviations from biological triplicates. * = p<0.05, ** = p<0.01, *** = p<0.001 difference relative to wild-type bars (Student’s T-test, unpaired, two-tailed).