Beunink J, Rehm H J
Institut für Mikrobiologie, Universität Münster, Federal Republic of Germany.
Appl Microbiol Biotechnol. 1990 Oct;34(1):108-15. doi: 10.1007/BF00170933.
The restriction of oxygen transfer in Ca-alginate beads used for the immobilization of microbial cells was applied to a coupled reductive and oxidative microbial degradation of the xenobiotic 4-chloro-2-nitrophenol (CNP). The conversion of CNP by Enterobacter cloacae under anaerobic conditions led to the formation of 4-chloro-2-aminophenol (CAP, 81%) and 4-chloro-2-acetaminophenol (CAAP, 16%) after 50 h incubation. CAP, the main reduction product, was further degraded under aerobic conditions by Alcaligenes sp. TK-2, a hybrid strain isolated by conjugative in-vivo gene transfer. Whereas both degradation steps excluded one another in homogeneous systems with free cells, a coupled reductive and oxidative degradation of CNP was observed in one aerated reactor system after co-immobilization of both strains in Ca alginate. The diameter of the alginate beads used for immobilization was recognized as one main factor determining the properties of this mixed culture system.
用于固定化微生物细胞的海藻酸钙珠粒中氧传递的限制被应用于异源生物4-氯-2-硝基苯酚（CNP）的还原和氧化耦合微生物降解。在厌氧条件下，阴沟肠杆菌对CNP的转化在孵育50小时后导致形成4-氯-2-氨基酚（CAP，81%）和4-氯-2-乙酰氨基酚（CAAP，16%）。主要还原产物CAP在有氧条件下被通过体内基因转移共轭分离得到的杂交菌株产碱杆菌属TK-2进一步降解。在游离细胞的均相系统中，两个降解步骤相互排斥，而在将两种菌株共固定在海藻酸钙中后，在一个曝气反应器系统中观察到了CNP的还原和氧化耦合降解。用于固定化的海藻酸钙珠粒的直径被认为是决定这种混合培养系统特性的一个主要因素。
