Nandakumar M P, Lali A M, Mattiasson B
Department of Biotechnology, Lund University, Sweden.
Bioseparation. 1999;8(1-5):229-35.
A novel flow injection biosensor system for monitoring fermentation processes has been developed using an expanded micro bed as the enzyme reactor. An expanded bed reactor is capable of handling a mobile phase containing suspended matter like cells and cell debris. Thus, while the analyte is free to interact with the adsorbent, the suspended particulate matter passes through unhindered. With the use of a scaled down expanded bed in the flow injection analysis (FIA) system, it was possible to analyse samples directly from a fermentor without the pretreatment otherwise required to extract the analyte or remove the suspended cells. This technique, therefore, provides a means to determine the true concentrations of the metabolites in a fermentor, with more ease than possible with other techniques. Glucose oxidase immobilised on STREAMLINE was used to measure glucose concentration in a suspension of dead yeast cells. There was no interference from the cell particles even at high cell densities such as 15 gm dry weight per litre. The assay time was about 6 min. Accuracy and reproducibility of the system was found to be good. In another scheme, lactate oxidase was covalently coupled to STREAMLINE for expanded bed operation. With the on-line expanded micro bed FIA it was possible to follow the fermentation with Lactobacillus casei.
一种用于监测发酵过程的新型流动注射生物传感器系统已被开发出来，该系统使用膨胀微床作为酶反应器。膨胀床反应器能够处理含有诸如细胞和细胞碎片等悬浮物的流动相。因此，当分析物能够自由地与吸附剂相互作用时，悬浮颗粒物则不受阻碍地通过。在流动注射分析（FIA）系统中使用小型化的膨胀床，就有可能直接对来自发酵罐的样品进行分析，而无需进行提取分析物或去除悬浮细胞所需的预处理。因此，这项技术提供了一种比其他技术更简便地测定发酵罐中代谢物真实浓度的方法。固定在STREAMLINE上的葡萄糖氧化酶被用于测量死酵母细胞悬浮液中的葡萄糖浓度。即使在高达每升15克干重的高细胞密度下，细胞颗粒也不会产生干扰。测定时间约为6分钟。该系统的准确性和重现性良好。在另一个方案中，乳酸氧化酶被共价偶联到STREAMLINE上以进行膨胀床操作。通过在线膨胀微床FIA，可以跟踪干酪乳杆菌的发酵过程。
