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本文在对普通培养条件下异养微生物粪产碱杆菌(Alcaligenes faecalis,A.faecalis)反硝化特征研究的基础上,运用电化学方法于一定电势下(-0.15 V、-0.06 V、+0.06 V vs.NHE)模拟半导体矿物导带光电子能量,探讨不同能量的光电子对A.faecalis反硝化特性及细胞生长代谢的影响。实验显示,在普通培养条件下,A.faecalis在有氧和无氧环境中均不能还原NO-3,但还原NO-2效果明显。在模拟光电子实验体系中,A.faecalis可在不同电势(-0.15 V、-0.06 V、+0.06 V)的阴极石墨电极表面附着并形成具有反硝化活性的菌膜;其中,外加电势为-0.15V的实验组菌膜量最多,其NO-3去除率也最高,10天达到52%;-0.06 V体系略低,NO-3去除率为30.5%,+0.06 V体系菌膜量最少,其NO-3去除效果也最差,仅为10.6%。而在不添加微生物的电化学体系中,3个外加电势下的NO-3浓度均未发生明显变化。本实验研究结果证明了一定能量的半导体矿物光电子可影响土壤异养微生物A.faecalis的生长代谢及反硝化行为。
In this paper, based on the denitrification characteristics of Alcaligenes faecalis (A. faecalis) cultured under ordinary culture conditions, the electrochemical method was used to determine the denitrification ability of A. californica at a certain potential (-0.15 V, -0.06 V, +0.06 V vs.NHE) to simulate photoelectron energies of semiconductor mineral conduction bands, and to explore the effect of photoelectrons with different energies on the denitrification characteristics of A.faecalis and cell growth and metabolism. Experiments show that under normal culture conditions, A.faecalis can not reduce NO-3 in aerobic and anaerobic environments, but the NO-2 reduction is obvious. In simulated photoelectron experimental system, A.faecalis could adhere to the surface of cathodic graphite electrode with different potentials (-0.15 V, -0.06 V, +0.06 V) and form a denitrifying bacterial membrane. Among them, the applied potential was -0.15 V was the highest in the experimental group with the highest NO-3 removal rate of 52% in 10 days; - 0.06 V system was slightly lower, NO-3 removal rate was 30.5%, + 0.06 V system was the least, NO-3 removal effect is also the worst, only 10.6%. In the electrochemical system without adding microorganisms, no significant changes were observed in the concentrations of NO-3 under the three applied potentials. The experimental results show that a certain energy of semiconductor mineral optoelectronics can affect the heterotrophic microorganism A.faecalis growth and metabolism and denitrification behavior.