• 作者： 王思達; 黃種金
• 作者服務機構： 食品工業發展研究所
• 中文摘要： 本研究以小型通氣攪拌醱酵槽，以及以過濾板或多孔板作為散氣裝置之氣?式醱酵槽，來進行醋酸醱酵深部培養之
  研究。先求出二種氣?式醱酵槽在各種通氣條件下之氣體塔箴量，以及三種醱酵槽在各種不同操作條件下之容積氧傳遞
  係數，並發現若以醋酵菌在各種培養條件下之比生長速率及比生產速率對各該條件下之溶氧濃度作圖，則對這三種不同
  的醱酵槽而言，可得三種不同的關係曲線。此結果顯示，在氣?式醱酵槽中，溶氧自液體傳至細胞表面的階段，其質傳
  阻力為顯著的。
  經提出一項氧傳遞機構之假說後，可以醋酸菌菌體表面之快速氧化反應，降低了菌體表面之溶氧濃度，以及醋酸菌
  產生之菌體外黏質層，提高了氧傳遞阻力，而產生極大之醱酵液與菌體表面溶氧濃度之差異，來解釋此現象。菌體外黏
  質層的厚度，可能受不同攪拌條件下，醱酵液亂流程度不同的影響，而有極大的差異。此種黏質層在不同攪拌程度下之
  差異，被認為是造成這種不同的生物活性與溶氧濃度間關係曲線的最主要原因。
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• 英文摘要： Submerged acetic acid fermentations were carried out in a jar fermentor and air-lift fermentors withsintered glass disc air distributor or perforated plate air distributor. Gas holdup for air-lift fermentors and values for all operating conditions for the three fermentors were determined. The specific growthrate and specific productivity of acetic acid under different operating conditions were also determinedand plotted versus dissolved oxygen concentration. It was found that a different type of fermentor gave adifferent biological activity-dissolved oxygen concentration curve. This result suggests that oxygen transferfrom bulk liquid to cell surface is not negligible in the acetification in air-lift fermentors. A mechanism is presented to hypothesize that the rapid oxidative reaction occurring at cell surfaceand the high resistance to oxygen transfer caused by extracellular slime layer are the two factors that gen-erate a large dissolved oxygen concentration difference between bulk liquid and cell surface. The thicknessof the slime layer is dependent on the shear of the broth in different operating conditions. It is the varia-tion of the slime thickness that is considered to bring about different biological activity-dissolved oxygenconcentration curves in different types of fermentors.
• 中文關鍵字： --
• 英文關鍵字： --