Faculty of Technology and Metallurgy, University SS Cyril and Methodius, Skopje, Republic of Macedonia.
Appl Biochem Biotechnol. 2010 Dec;162(8):2214-20. doi: 10.1007/s12010-010-8995-z. Epub 2010 May 29.
A new lyophilization technique was used for immobilization of Saccharomyces cerevisiae cells in hydroxyethylcellulose (HEC) gels. The suitability of the lyophilized HEC gels to serve as immobilization matrices for the yeast cells was assessed by calculating the immobilization efficiency and the cell retention in three consecutive batches, each in duration of 72 h. Throughout the repeated batch fermentation, the immobilization efficiency was almost constant with an average value of 0.92 (12-216 h). The maximum value of cell retention was 0.24 g immobilized cells/g gel. Both parameters indicated that lyophilized gels are stable and capable of retaining the immobilized yeast cells. Showing the yeast cells propagation within the polymeric matrix, the scanning electron microscope images also confirmed that the lyophilization technique for immobilization of S. cerevisiae cells in the HEC gels was successful. The activity of the immobilized yeast cells was demonstrated by their capacity to convert glucose to ethanol. Ethanol yield of 0.40, 0.43 and 0.30 g ethanol/g glucose corresponding to 79%, 84% and 60% of the theoretical yield was attained in the first, second and third batches, respectively. The cell leakage was less than 10% of the average concentration of the immobilized cells.
一种新的冻干技术被用于将酿酒酵母细胞固定在羟乙基纤维素（HEC）凝胶中。通过计算三次连续批次（每次持续 72 小时）中的固定化效率和细胞保留率，评估了冻干 HEC 凝胶作为酵母细胞固定化基质的适用性。在重复批次发酵过程中，固定化效率几乎保持不变，平均值为 0.92（12-216 小时）。细胞保留的最大值为 0.24 g 固定化细胞/g 凝胶。这两个参数表明冻干凝胶是稳定的，能够保留固定化的酵母细胞。扫描电子显微镜图像显示了酵母细胞在聚合物基质内的繁殖，也证实了将酿酒酵母细胞固定在 HEC 凝胶中的冻干技术是成功的。通过其将葡萄糖转化为乙醇的能力，证明了固定化酵母细胞的活性。在第一批、第二批和第三批中，相应的乙醇得率分别为 0.40、0.43 和 0.30 g 乙醇/g 葡萄糖，分别达到理论产量的 79%、84%和 60%。细胞泄漏量低于固定化细胞平均浓度的 10%。
