Abstract As a solution to the problems of mass transfer limitation in submerged cultures and scale up of solid-state/liquid-surface cultures, an alternating liquid phase–air phase bioreactor was developed. It consisted of a bioreactor equipped with a siphon system and a reservoir. Aspergillus awamori was immobilized in loofa sponge inside the bioreactor and culture broth was pumped from the reservoir into the bioreactor. Each time the culture broth level reached a critical level, the broth automatically siphoned back into the reservoir. Thus the immobilized cells were alternatingly submerged and exposed to air. The duration of each phase was controlled by the pumping rate and with an on-off timer. During amylase production from soluble starch and raw cassava starch, the optima ratios of the liquid to air phases were 12 h : 12 h and 3 h : 6 h respectively. Saccharomyces cerevisiae IR2 was immobilized in the reservoir and the system was used for simultaneous amylase production, hydrolysis and ethanol production from raw cassava starch. The process was very stable for more than 7 batches with high ethanol yield of 0.46 g-ethanol/g-starch and productivity of 1.73 g-ethanol/L/h. These values are high, the system can be scaled up, and thus it has many potential applications.

中文翻译：

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固定化泡盛曲霉和酿酒酵母在新型交替液相-气相系统中同时生产淀粉酶、生木薯淀粉水解和乙醇生产

摘要 为了解决浸没培养中传质限制和固态/液面培养放大的问题，开发了一种液相-气相交替生物反应器。它由配备虹吸系统和水库的生物反应器组成。泡盛曲霉固定在生物反应器内的丝瓜海绵中，并将培养液从水库泵入生物反应器。每次培养肉汤液位达到临界水平时，肉汤会自动虹吸回水库。因此，固定化的细胞交替浸没并暴露于空气中。每个阶段的持续时间由泵速和开关计时器控制。在从可溶性淀粉和生木薯淀粉生产淀粉酶的过程中，液相与气相的最佳比例为 12 小时：12 小时和 3 小时：分别为 6 小时。Saccharomyces cerevisiae IR2 被固定在水库中，该系统用于从生木薯淀粉中同时生产淀粉酶、水解和乙醇生产。该工艺在超过 7 个批次时非常稳定，乙醇产率为 0.46 g-乙醇/g-淀粉，生产率为 1.73 g-乙醇/L/h。这些值很高，系统可以按比例放大，因此具有许多潜在的应用。