Wijffels R H, Hunik J H, Leenen E J, Günther A, de Castro J M, Tramper J, Englund G, Bakketun A
Wageningen Agricultural University, Department of food Science, Food and Bioprocess Engineering Group, P.O. Box 8129, 6700 EV Wageningen, The Netherlands.
Biotechnol Bioeng. 1995 Jan 5;45(1):1-9. doi: 10.1002/bit.260450102.
Activation energies of suspended and immobilized nitrifying bacteria were determined and compared to determine if diffusion limitation results in decreased sensitivity for temperature. The activation energy for the respiration activity of suspended Nitrosomonas europaea and Nitrobacter agilis was found to be 86.4 and 58.4 kJ mol(-1), respectively. The activation energy for oxygen diffusion in the support material, kappa-carrageenan, determined from the effect of temperature on the effective diffusion coefficient (D), was 17.2 kJ mol(-1). Consequently, the apparent actvation energy of diffusion limited cells should be lower. It was indeed shown that due to the effect of diffusion limitation and to temperature effects on the Monod constant K(s), the immobilized-cell activity was less sensitive to temperature. The apparent activation energy for immobilized Ns. europaea was between 28.6 and 94.2 kJ mol(-1) and for immobilized Nb. agilis between 1.4 and 72.9 kJ mol(-1), depending on the oxygen concentration and temperature. (c) 1995 John Wiley & Sons, Inc.
测定并比较了悬浮态和固定化硝化细菌的活化能，以确定扩散限制是否会导致对温度的敏感性降低。悬浮态欧洲亚硝化单胞菌和敏捷硝化杆菌呼吸活性的活化能分别为86.4和58.4 kJ mol⁻¹。根据温度对有效扩散系数（D）的影响确定，载体材料κ-卡拉胶中氧气扩散的活化能为17.2 kJ mol⁻¹。因此，扩散受限细胞的表观活化能应该更低。确实表明，由于扩散限制的影响以及温度对莫诺德常数Kₛ的影响，固定化细胞活性对温度的敏感性较低。固定化欧洲亚硝化单胞菌的表观活化能在28.6至94.2 kJ mol⁻¹之间，固定化敏捷硝化杆菌的表观活化能在1.4至72.9 kJ mol⁻¹之间，具体取决于氧气浓度和温度。（c）1995约翰·威利父子公司
