Abstract: A process for aerobic culture in which ammonia and oxygen are simultaneously supplied, comprising: dispersing and supplying air, oxygen, or a mixed gas thereof into a culture tank through a sintered metal membrane attached the end of a diffusing pipe, and simultaneously, dispersing and supplying ammonia or a mixed gas of ammonia and air into the culture tank through a diffusing pipe other than the above diffusing pipe.

Abstract: A foam detecting sensor (7) and an ultrasonic oscillation horn (13) are mounted on a vertical pipeline between a culture tank (1) and a liquid-vapor separating device (5). When overflowed foams are subjected to ultrasonic irradiation, they burst and lose volume. The burst foams have high apparent density as compared to the foams before irradiation. Thus, the concurrent use of ultrasonic oscillation devices (12, 13) and the liquid-vapor separating device (5), such as cyclone, leads to an enhanced liquid-vapor separation efficiency and higher productivity by fermentation.

Abstract: A process for aerobic culture in which ammonia and oxygen are simultaneously supplied, comprising: dispersing and supplying air, oxygen, or a mixed gas thereof into a culture tank through a sintered metal membrane attached the end of a diffusing pipe, and simultaneously, dispersing and supplying ammonia or a mixed gas of ammonia and air into the culture tank through a diffusing pipe other than the above diffusing pipe.

Abstract: A foam detecting sensor (7) and an ultrasonic oscillation horn (13) are mounted on a vertical pipeline between a culture tank (1) and a liquid-vapor separating device (5). When overflowed foams are subjected to ultrasonic irradiation, they burst and lose volume. The burst foams have high apparent density as compared to the foams before irradiation. Thus, the concurrent use of ultrasonic oscillation devices (12, 13) and the liquid-vapor separating device (5), such as cyclone, leads to an enhanced liquid-vapor separation efficiency and higher productivity by fermentation.

Abstract: A stirring blade unit includes a perforated cylinder formed around the an internal stirring blade so as to be rotated together with the stirring shaft. The perforated cylinder has perforations which are approximately 30 to 50% of the area of the top and bottom surface of the perforated cylinder. The internal stirring blade unit uses a discharge type stirring blade unit used for gas-liquid mixing of a general fermentation tank. Thus, the gas-liquid flow discharged from the blade unit in the horizontal direction hits the perforated cylinder formed around the blade unit certainly. Due to this hitting of the gas-liquid flow against the perforated cylinder, the pressure of the flow is changed significantly to refine the gas bubbles so that the gas absorption property is improved. The stirring blade unit is suitable for gas-liquid mixing necessary for such as, fermentation, aeration, and reaction (hydrogenation and oxidation) tanks.