バイオリアクターによる食酢製造工程の改善に関する研究 第５報 濃縮菌体の一部排出培養法による高酸度食酢の連続生産における培養温度の影響

Abstract

To raise the acetic acid concentration and enhance productivity, the effect of cultivation temperature in the second fermentor was studied on continuous production of vinegar using hollow fiber module and two fermentors. ln the second fermentor, the cells were concentrated with a hollow fiber module and some portion of concentrated celis were discharged to suppress excessive increase in ce11 concentration. Cultivation temperature was regulated at 30°C in the first fermentor and varied from 20 to 30°C in the second fermentor. Fresh medium of an ethanol concentration of 13% (v/v) at a rate of 100 ml/h was fed. A broth containing 117 g-acetic acid/l of acetic acid and 0.114 g-dry cell/l of cell was produced in the first fermentor and supplied to the second fermentor. ln the second fermentor, cells were concentrated with a hollow fiber module and was discharged at a discharge ratio of 0.1. The acetic acid concentration reached 156 g-acetic acid/l at 24°C and was constant below 24°C. Total acetic acid production rate and the yield of both fermentors was 3.0 g-acetic acid (l·h) and 0.94 g-acetic acid/1.304 g-consumed ethanol respectively. In the acetic acid production, the ratio of contribution of the first and second fermentor was estimated as 0.72:0.28.