Abstract
At Inachuo sanitation center-facility, extremly effective aerobic digestion treatment of night soil has been accomplished. In order to analyze dominant bacteria and to elucidate the biochemical characteristics of them, bacteria were isolated from the activated sludge of aerobic digestion tanks. The number of colonies was 5 ×107- 5 × 1010ml-1, and 92-98% of them was of Bacillus spp. 32 strains of Bacillus spp., 1 strain of Nocardioform bacterium and 2 strains of gram negative bacteria were isolated. Additionally, 2 strains of yeasts were isolated. Bacillus spp. isolated were classified into 2 types. One solubilized starch, but not cooked meat, and the other did cooked meat, but not starch. Some strains of Bacillus spp. assimilated soybean oil. All strains decomposed hydrogen sulfide and assimilated diethyl amine. Some strains used ammonia as the source of nitrogen, and showed denitrification-ability. Decomposition of night soil was accomplished using some strains of Bacillus spp. The mechanisms of dominant growth of Bacillus spp. and the relationship of Bacillus spp. with buking were discussed.
