Fundamental Research on the Development of Bioelectrochemical Cells

1悬浮在缓冲溶液中的普通脱硫弧菌全细胞作为均相催化剂，在甲基紫精(MV)存在下产生电化学催化电流，用于H&lt；&gt；的产生和消耗。利用生物电催化理论对催化电流进行了分析，结果表明，普通假丝酵母细胞中的氢酶是一种非常有效的催化剂，可以促进H^/H_2对的间接电化学氧化还原反应。因此，在中性pH的环境温度下，反应是可逆进行的。计算出反应速度是扩散控制的，这表明利用细菌细胞构建生物电化学电池的功能阳极是非常有前途的。2类似地，当Fe(CN)_6^&lt；3-&gt；/Fe(CN)_6^&lt；4-&gt；氧化还原对作为细菌…之间的电子转移介体时，氧化亚铁硫杆菌可以催化O_&lt；&gt；生成H_&lt；&gt；O更多的L细胞和一个电极。氧化亚铁酵母细胞的转化也非常有效地产生了大的催化阴极电流以消耗溶液中的O_2。然而，只有在酸性pH下才能观察到较高的催化活性。因此，当我们想要在中性pH下操作生物电化学池时，氧化亚铁硫杆菌并不是电化学还原O2的最佳催化剂。3乙酸乙酯以2-甲基-5，6-二甲氧基苯醌(Q0)为电子载体催化乙醇的氧化。对其电催化行为进行了详细的研究，利用极谱动力学电流理论对催化电流进行了分析，由此可以计算出细菌细胞与Q0之间的双分子速率常数很大。该体系适用于以乙醇为燃料的生物电化学池的构建。4对碳毡作为大电流输出电极进行了简单的测试，发现它作为生物电化学池的电极材料是非常有前途的。较少

1 Whole cells of Desulfovibrio vulgaris suspended in a buffer solution function as homogeneous catalysts to produce an electrochemical catalytic current for the production and consumption of H_<> in the presence of methyl viologen (MV). Analysis of the catalytic current by the theory of bioelectrocatalysis revealed that hydrogenase in the D.vulgaris cells function as a very effective catalyst to promote the indirect electrochemical redox reaction of H^+/H_2 couple. Thus, the reaction proceeds reversibly under such mild conditions as an ambient temperature at neutral pH.The rate of the reaction is calculated to be diffusion- controlled, indicating that the use of the bacterial cells is very promising for constructing a functional anode of bioelectrochemical cells.2 Similarly, Thiobacillus ferrooxidans functioned as a catalyst for the electorchemical reduction of O_<> to H_<>O when Fe(CN)_6^<3->/Fe(CN)_6^<4-> redox couple was employed as an electron transfer mediator between the bacteria … More l cells and an electrode. The conversion by T.ferrooxidans cells was also very effective to produce a large catalytic cathodic current for the consumption of O_2 in solution. However, the high catalytic activity was observed only at acidic pH.Consequently, T.ferrooxidans is concluded not to be a best choice as a biocatalyst for the electrochemical reduction of O_2 when we would like to operate bioelectrochemical cells at neutral pH.3 A.aceti catalyzes the oxidation of ethanol with 2-methyl-5,6-dimethoxy benzoquinone (Q_0) as an electron carrier. The electrocatalytic behavior was studied in detail, the theory of polarographic kinetic current was available for analyzing the catalytic current, from which the bimolecular rate constant between the bacterial cell and Q_0 could be calculated to be very large. This system is applicable to the construction of bioelectrochemical cells which use ethanol as a fuel.4 Carbon felt was briefly examined as an electrode of large scale current out put, and found to be very promising as an electrode material of bioelectrochemical cells. Less