A Procedure for High-Yield Spore Production by Bacillus subtilis

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• 作者：Sandra M. Monteiro ; Joã ; o J. Clemente ; Adriano O. Henriques ; Rui J. Gomes ; Manuel J. Carrondo ; and Antó ; nio E. Cunha
• 刊名：Biotechnology Progress
• 出版年：2005
• 出版时间：August 2005
• 年：2005
• 卷：21
• 期：4
• 页码：1026 - 1031
• 全文大小：114K
• 年卷期：v.21,no.4(August 2005)
• ISSN：1520-6033

文摘

Bacillus subtilis spores have a number of potential applications, which include theiruse as probiotics and competitive exclusion agents to control zoonotic pathogens inanimal production. The effect of cultivation conditions on Bacillus subtilis growth andsporulation was investigated in batch bioreactions performed at a 2-L scale. Studiesof the cultivation conditions (pH, dissolved oxygen concentration, and media composition) led to an increase of the maximum concentration of vegetative cell from 2.6 ×10⁹ to 2.2 × 10¹⁰ cells mL^-1 and the spore concentration from 4.2 × 10⁸ to 5.6 × 10⁹spores mL^-1. A fed-batch bioprocess was developed with the addition of a nutrientfeeding solution using an exponential feeding profile obtained from the mass balanceequations. Using the developed feeding profile, starting at the middle of the exponentialgrowth phase and finishing in the late exponential phase, an increase of the maximumvegetative cell concentration and spore concentration up to 3.6 × 10¹⁰ cells mL^-1 and7.4 × 10⁹ spores mL^-1, respectively, was obtained. Using the developed fed-batchbioreaction a 14-fold increase in the concentration of the vegetative cells was achieved.Moreover, the efficiency of sporulation under fed-batch bioreaction was 21%, whichpermitted a 19-fold increase in the final spore concentration, to a final value of 7.4 ×10⁹ spores mL^-1. This represents a 3-fold increase relative to the highest reportedvalue for Bacillus subtilis spore production.