earticle

영어

In lactic acid fermentation, the end product inhibition by lactic acid causes several problems. The most important of which are low lactate formation rate and its recovery from fermentation broth. To overcome these problems, extractive lactic acid fermentation was carried out in a bioreactor, which was connected to a column packed with anion exchange resin (Amberlite IRA-400, 250 g). The system was started as a batch process, and then the separation process was
started when the lactic acid concentration reached 10 g/L, 20 g/L or 30 g/L. In each case, total lactic acid concentration was reached to 48.6, 53.6, 52.6 g/L with its productivity of 1.2 g/L․h, 1.6 g/L․h, and 1.3 g/L․h, respectively. Especially, in the case of the 20 g/L recycling-initiation process, extractive fermentation reduced the fermentation time (17 hrs) by 34% in comparison with the conventional batch process. The direct consequence of this time reduction was shown by a 1.8 fold increase in overall lactic acid productivity.

한국어

Lactococcus lactis IO-1를 이용하여 xylose로부터 젖산발효를 수행한 결과 기질농도가 50 g/L에서 100 g/L로 증가됨에 따라 생육저해 및 생산성감소가 일어났다. 따라서 이온교환 수지(Amberlite IRA-400, 250 g)를 이용하여 젖산을 발효 중에 제거함으로 최종산물저해를 완화시킬 수 있는 추출발효를
수행하였다. 초기 xylose 100 g/L에서 발효조내 젖산농도 20 g/L에서 추출발효를 시작한 결과 기질을 거의 모두 소비하여 총 53.6 g/L의 젖산을 생산하였으며 1.6 g/L․h의 생산성을 나타냈다. 이는 일반적인 회분발효에 비해 약 1.8배 향상된 결과로써 향후 수지에 젖산의 흡착을 저해하는 문제점을 개선함으로써 이온교환수지의 젖산 흡착량을 늘릴 수 있는 방안을 모색한다면 지금 보다 더 나은 생산성을 나타낼 것으로 사료된다.