DECOMPOSITION OF BLUE-GREEN ALGAE AS EFFECTED BY THE ACTION OF SOIL BACTERIA

Abstract

The decomposition of the nitrogen-fixing blue-green algae, Tolypothrix tenuis, Calothrix brevissima, Nostoc muscorum and Anabaenopsis circularis, brought about by the action of various soil bacteria was examined. A certain strain of Bacillus subtilis was found to give the most active production of ammonia; about 40 per cent of the algal nitrogen being converted to ammonia within 10 days of incubation. Practically no production of nitrogenous compounds other than ammonia was observed. On the basis of these results, the varying efficacy of blue-green algae as fertilizer in paddy fields was discussed.