Comparison of nicotinamide adenine dinucleotide synthesis by Mycobacterium tuberculosis and Mycobacterium bovis.

The R1Rv strain of M. tuberculosis utilized nicotinic acid for the synthesis of nicotinamide adenine dinucleotide (NAD). Nicotinic acid mononucleotide (NaMN) and nicotinic acid dinucleotide (NaAD) were identified among the enzymatic reaction mixture products. A comparison with M. bovis demonstrated a greater capacity for NAD synthesis by the bovine bacillus. It has been hypothesized that reduced NAD synthesis and failure to utilize intermediates which continue to be produced are responsible for the excessive nicotinic acid accumulation by M. tuberculosis.