HWAHAK KONGHAK, Vol.18, No.5, 333-342, October, 1980
2단 연속식 발효 방식에 의한 솔비톨로부터의 솔보즈 생산: 조업 조건의 최적화
Production of Sorbose from Sorbitol using a Two-Stage Continuous Bio-Reactor System: Optimization of Operating Condition
초록
Glucose를 starting material로 하는 vitamin C 생산에 있어서 중요한 중간 물질인 sorbose의 2단 연속식 발효 방식에 의한 생산에 대하여 연구하였다. Sorbitol의 탈수소 반응에 의한 sorbose의 생성은 화학적인 방법으로도 그 진행이 가능하지만 L-, D-형의 sorbose racemate가 생기기 때문에 그 수율면에서 미생물에 의한 발효에 뒤지고 있다. 회분식 발효에 있어서 기질 농도가 20 %일 때 90 %의 전화율과 19 mmole/l/hr의 생산율을 얻었다. 회분식 실험에 의하여 sorbose의 생산은 발효액 중의 미생물 농도에 비례함을 알았고 미생물 농도를 증가시키기 위하여 연속식 발효 방식, 특히 여과장치를 갖춘 2단 연속식 발효 방식을 사용하여 생산율 증가를 시도하였다. 온도 29 ℃ pH 4.6, 기질농도 20 % 등 최적 발효조건을 유지하여 90 %의 전화율에서 45 mmole/l/hr의 생산율을 얻을 수 있었으며 이것은 회분식 최대 생산율의 2배 이상에 해당하는 값이다.
Using a two-stage continuous culture system, the parameters that affect the productivity of sorbose were studied and the operating conditions which correspond to the maximal productivity of sorbose were determind.
The maximum specific growth rate of Acetobacter suboxydans strain employed was 0.31 hr-1 and its optimal growth pH was determined as 4.6. The maximum productivity of sorbose obtained employing a batch culture system was 19 mmole/liter/hr at 90 % conversion level. The enzymatic conversion of sorbose was found to be proportional to the cell concentration, and the cell concentration in the second-stage continuous bioreactor was increased by using a filter system installed at the effluent line.
Under the optimal operating conditions, 29 ℃, pH 4.6, and sorbitol concentration 20 %, the two-stage continuous fermentation system yielded the productivity of 45 mmole sorbose/liter/hr while maintaining 90 % or higher level of conversion, indicating that a significant improvement in the sorbose productivity could be achieved by employing the two-stage continuous bioreactor system combined with the cell enrichment technique.
The maximum specific growth rate of Acetobacter suboxydans strain employed was 0.31 hr-1 and its optimal growth pH was determined as 4.6. The maximum productivity of sorbose obtained employing a batch culture system was 19 mmole/liter/hr at 90 % conversion level. The enzymatic conversion of sorbose was found to be proportional to the cell concentration, and the cell concentration in the second-stage continuous bioreactor was increased by using a filter system installed at the effluent line.
Under the optimal operating conditions, 29 ℃, pH 4.6, and sorbitol concentration 20 %, the two-stage continuous fermentation system yielded the productivity of 45 mmole sorbose/liter/hr while maintaining 90 % or higher level of conversion, indicating that a significant improvement in the sorbose productivity could be achieved by employing the two-stage continuous bioreactor system combined with the cell enrichment technique.