Bioreactor design and operation strategies for repeated surfactin fermentation

• Main Authors: Chin-I Hsieh, 謝勤毅
• Other Authors: Jo-Shu Chang
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/33755701090628023346

碩士 === 國立成功大學 === 化學工程學系碩博士班 === 95 === Bacillus subtilis ATCC 21332 was used to produce surfactin via repeated operations. Surfactin, a lipopeptide biosurfactant, is recognized as one of the most effective biosurfactant available and possesses promising commercial applications. This motivated us to develop viable fermentation technology to produce surfactin in a more efficient way in order to lower the high production cost. In our recent studies, excellent surfactin producing performance was achieved in batch fermentation from innovative bioreactor design and addition of solid carrier as stimulator for surfactin production. In the present study, strategies enabling repeated operation for surfactin production were developed. The first attempt was using immobilized cell systems. Of the immobilized-cell system examined, PU (polyurethane- polyurea copolymer) immobilized cells supplemented with activated carbon resulted in the best performance with a surfactin concentration of 1,340 mg/L, and the particles were easy to be operated repeatedly. On the other hand, repeated operation with suspended-cell system was also attempted using innovative bioreactor design, in which an outer circulation activated carbon cassette system was equipped. This bioreactor setup allowed production of a high surfactin concentration of 6000 mg/L in the first two repeated batches.