It was confirmed that the ACC deaminase deficient mutants no longer exhibit significant ACC deaminase activity.
The ACC deaminase activity of wild-type P. fluorescens YsS6 was 12.5 mmol mg1 h1 while the ACC deaminase deficient mutant activity was 0.11 mmol mg1 h1; wild-type P. migulae 8R6 and its ACC deaminase deficient mutant had activity levels of 10.9 and 0.03 mmol mg1 h1, respectively