Fed-batch culture of Bacillus thuringiensis based on motile intensity.
The operation of a fed-batch culture is more complicated than that of batch or continuous culture. Thus, an appropriate feeding strategy for fed-batch cultures should be carefully designed. In this study, a simple feeding strategy for fed-batch culture of Bacillus thuringiensis based on "motile intensity" is described. The feeding strategy consisted of two steps: (1) initiating feeding at the peak of motile intensity; (2) terminating feeding at low motile intensity (or non-motility) of the cells. In addition, the motile intensity of B. thuringiensis was used to determine the optimum environmental conditions (pH, temperature, and dissolved oxygen) and optimum medium composition. Using this fed-batch strategy, the production of thuringiensin increased 34% compared with batch culture using the same environmental conditions and medium composition. The proposed strategy for fed-batch culture helps to avoid overfeeding of substrate and facilitates on-line control. A comparison of several alternative strategies for fed-batch culture demonstrated that strategies such as glucose-stat and DO-stat result in a lower productivity than that obtained using the motility intensity method.
Chen
S
S
Department of Chemical Engineering, National Tsing Hua University, 30043, Hsinchu, Taiwan.
Hong
J-Y
JY
Wu
W-T
WT
D000241:Adenosine / Q000031:analogs & derivatives* / Q000096:biosynthesis; D001413:Bacillus thuringiensis / Q000254:growth & development* / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism; D003470:Culture Media; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology / Q000379:methods*; D009584:Nitrogen / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D013400:Sugar Acids
D003470:Culture Media; D013400:Sugar Acids; D002244:Carbon; C068295:thuringiensin; D000241:Adenosine; D009584:Nitrogen; D010100:Oxygen