The succinate oxidase activity of Mycobacterium phlei was sensitive to irradiation with light at 360 mp. The loss of activity was due to a lesion occurring in the electron transport chain between the flavoprotein and cytochrome b regions. The activity lost was not restored by addition of vitamin Kr or other cofactors but could be restored by the addition of the supernatant fraction. The factor ...

With the techniques found suitable for the growth of tubercle bacilli in HeLa cells (Shepard, 1955, 1957a) little extracellular bacterial growth occurs when virulent strains are used. When rapidly growing mycobacteria (Gordonand Smith, 1953, 1955) are introduced into the tissue cultures in the same concentration, bacterial growth in the extracellular tissue culture fluid is rapid and soon resul...