Abstract
SUMMARY: The results are presented of a survey of NAD and NADP concentration in twenty micro-organisms. They fell into three categories with respect to NAD concentration. (i) High NAD (> 4·5 μmoles/g. dry weight) in obligate anaerobes, members of the Lactobacillaceae and Saccharomyces cerevisiae. (ii) Medium NAD (1·0-3·0 μmoles/g. dry weight) in faculative anaerobes, photosynthetic bacteria and Nocardia globerula. (iii) Low NAD (< 0·9 μmoles/g. dry weight) in obligate aerobes.