|Budget Amount *help
¥2,300,000 (Direct Cost : ¥2,300,000)
Fiscal Year 1994 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1993 : ¥1,400,000 (Direct Cost : ¥1,400,000)
1. Two types of bacteria such as acetic acid bacteria, Acetobacter aceti, and alcohol producing bacteria, Zymomonas mobilis, and other monocelluler microorganisms such as soy sauce yeast, Zygosaccharomyces rouxii, were investigated.
2. A.aceti were continuously cultivated using a fluidized bed bioreactor. Immobilized growing bacteria exhibited high metabolic activity and synchronized growth at a supercritical dilution rate in either acetic acid-cluding (AC) medium or acetic acid-noncluding (NC) medium, and the specific growth rate, mu, and the specific production rate of acetic acid, rho, changed concurrently against a dilution rate, D.The relationship between mu and rho was fitted as rho=amu^2 in NC medium, and rho=amu^<3.9> in AC medium, and similarly indicated positive correlatation and remarkable energy wastefulness. Nonimmobilized bacteria exhibited washing out at a lower dilution rate, and mu and rho changed without concurrence. These showed that immobilized growing bacteria were
advantageous for acetic acid production because they indicated high ratio of acetic acid production to cell growth.
3. Zm.mobilis were continuously cultivated using a fixed bed column bioreactor. Immobilized growing bacteria indicated a high product concentration and a high productivity concurrently by cascade feeding at a supercritical dilution rate in high-substrate medium with 3-stage continuous culture.
4. Other microorganisms, Zs.rouxii, continuously cultivated using a fluidized bed bioreactor. Immobilized growing cells exhibited concurrent change of mu and rho and synchronized growth similarly to Acetobacter at a supercritical dilution eate, and indicated the relationship between mu and a respiratory activity, Qo_2, as Qo_2=dmu^<1.7> and energy wastefulness.
5. It was suggested, the phenomenon as immobilized growing microorganisms exhibited high metabolic activity and concurrent growth activity and energy wastefullness was found in monocellular microorganisms at a wide range. Immobilized growing microorganisms could have a high product concentration and high productivity concurrently at a supercritical dilution rate. Less