The metabolism, population dynamics and spa-tial distribution of nitrifying bacteria and heterotrophs in biofilms under the action of direct electric current were in-vestigated by using the micro-slicing technique. Th...The metabolism, population dynamics and spa-tial distribution of nitrifying bacteria and heterotrophs in biofilms under the action of direct electric current were in-vestigated by using the micro-slicing technique. The nitrifi-cation rate of nitrifying bacteria was severely inhibited by a current over 10 Am-2 at lower C/N ratios. Compared to het-erotrophs, the nitrifying bacteria in the surface biofilms were severely inhibited, resulting in a significant decrease in bac-terial density. An increase in current density narrowed the less current-sensitive inner biofilm region, and in addition the density of NO2-oxidizers decreased more significantly than that of NH4-oxidizers in the surface biofilms probably due to electrochemical reactions at the anode. However, the effect of current on both the population dynamics and the spatial distribution of the microbial species was less signifi-cant at larger C/N ratios.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.29976030)the Foundation for University Key Teacher of the Ministry of Education of China
文摘The metabolism, population dynamics and spa-tial distribution of nitrifying bacteria and heterotrophs in biofilms under the action of direct electric current were in-vestigated by using the micro-slicing technique. The nitrifi-cation rate of nitrifying bacteria was severely inhibited by a current over 10 Am-2 at lower C/N ratios. Compared to het-erotrophs, the nitrifying bacteria in the surface biofilms were severely inhibited, resulting in a significant decrease in bac-terial density. An increase in current density narrowed the less current-sensitive inner biofilm region, and in addition the density of NO2-oxidizers decreased more significantly than that of NH4-oxidizers in the surface biofilms probably due to electrochemical reactions at the anode. However, the effect of current on both the population dynamics and the spatial distribution of the microbial species was less signifi-cant at larger C/N ratios.
