Catalase enzyme activity
Cells from mid-log phase cultures of M. bovis transformants were collected by centrifugation at 20,000×g for 20 min and washed three times with cold phosphate-buffered saline (PBS). Cells were smeared onto a clean microscope slide and one drop of 3% H2O2 was added. Catalase activity was indicated by the generation of bubbles (Pritchard et al., 2014).