Martin C K, Perlman D
Biotechnol Bioeng. 1976 Feb;18(2):217-37. doi: 10.1002/bit.260180208.
Gluconobacter melanogenus IFO 3293 cells capable of converting L-sorbose to L-sorbosone were immobilized in polyacrylamide gel. The preferred polymer composition for high activity and stability was determined to contain a total monomer concentration of 7.2% and 16.6% crosslinking agent. No significant differences in optimal conditions for conversion, e.g., pH and temperature, were found in comparison with free cell suspensions. However, in the absence of L-sorbose, the thermal stability of immobilized cells was lower. After the initial loss, the conversion activity of immobilized cells increased, possibly due to lysis, and this increase was related to the polymerization conditions and the incubation temperature for the L-sorbose conversion. The enzymatic activity and stability of the immobilized cells also depended on the physical form of the gel and the aeration levels. Addition of electron acceptors or addition of L-sorbosone to the medium reduced, while addition of neomycin, ampicillin, chloramphenicol, and tetracycline increased the stability of the enzymatic activity.
能够将L-山梨糖转化为L-山梨糖酮的生黑葡萄糖杆菌IFO 3293细胞被固定在聚丙烯酰胺凝胶中。确定具有高活性和稳定性的优选聚合物组合物含有7.2%的总单体浓度和16.6%的交联剂。与游离细胞悬液相比，在转化的最佳条件（例如pH和温度）方面未发现显著差异。然而，在没有L-山梨糖的情况下，固定化细胞的热稳定性较低。在最初的活性损失之后，固定化细胞的转化活性增加，这可能是由于细胞裂解，并且这种增加与聚合条件和L-山梨糖转化的培养温度有关。固定化细胞的酶活性和稳定性还取决于凝胶的物理形式和通气水平。向培养基中添加电子受体或添加L-山梨糖酮会降低酶活性，而添加新霉素、氨苄青霉素、氯霉素和四环素会增加酶活性的稳定性。
