Studies on the Marine Microorganisms Utilizing Inorganic Nitrogen Compounds-I

On the Marine Denitrifying Bacteria

Abstract

1. The distribution of marine denitrifying bacteria in Maizuru Bay and Wakasa Bay were investigated, the methods to count and assort the bacteria being clarified.
2. The counts of marine denitrifying bacteria were comparatively large in bottom muds and sea water, i. e. 10²-10⁵ cells/g and 10⁰-10² cells/ml, respectively.
3. Of these bacteria, the counts of three types I (NO₃→NO₂), II (NO₃→NO₂→NH₃) and IV (NO₂→NH₃) were 10-80 per cent of those of total heterotrophic bacteria, although the counts of both types III (NO₃→NO₂→N₂) and V (NO₂→N₂) were only a few per cent or less of those of total heterotrophic ones. Further, these percentages of the bacteria in sea water were smaller as compared with those in bottom muds.