Nitrate reduction in so-called nitrate reductase (NR) negative strains of the genus Mycobacterium

The goal of our present investigations was to complete our knowledge concerning the actual ability to reduce nitrate within the genus Mycobacterium and to eliminate previously reported results like "weakly reaction" or "variable reactions". The influence of conditions like reaction temperature and reaction time, substrate concentration, H+-donors, ammonia and the presence of the nitrate reductase were studied. The results can be summated as follows: 1. The nitrate reductase is more widespread within the genus Mycobacterium than it has been reported by other previous investigators. - 2. Previously doubtful results can be understood. - 3. By means of proper experimental conditions M. chelonei ssp. borstelense can be easily separated from M. chelonei ssp. chelonei, although, according to Bergey's Manual of Determinative Bacteriology, they are recommended as synonyms.