Sørensen J, Tiedje J M, Firestone R B
Appl Environ Microbiol. 1980 Jan;39(1):105-8. doi: 10.1128/aem.39.1.105-108.1980.
The influence of low redox potentials and H2S on NO and N2O reduction by resting cells of denitrifying Pseudomonas fluorescens was studied. Hydrogen sulfide and Ti(III) were added to achieve redox potentials near -200 mV. The control without reductant had a redox potential near +200 mV. Production of 13NO, [13N]N2O, and [13N]N2 from 13NO3- and 13NO2- was followed. Total gas production was similar for all three treatments. The accumulation of 13NO was most significant in the presence of sulfide. A parallel control with autoclaved cells indicated that the 13NO production was largely biological. The sulfide inhibition was more dramatic at the level of N2O reduction; [13N]N2O became the major product instead of [13N]N2, the dominant product when either no reductant or Ti(III) was present. The results indicate that the specific action of sulfide rather than the low redox potential caused a partial inhibition of NO reduction and a strong inhibition of N2O reduction in denitrifying cells.
研究了低氧化还原电位和H2S对反硝化荧光假单胞菌静息细胞还原NO和N2O的影响。添加硫化氢和Ti(III)以实现接近-200 mV的氧化还原电位。无还原剂的对照氧化还原电位接近+200 mV。跟踪了13NO3-和13NO2-生成13NO、[13N]N2O和[13N]N2的过程。三种处理的总气体产量相似。在有硫化物存在的情况下，13NO的积累最为显著。用高压灭菌细胞进行的平行对照表明，13NO的产生主要是生物作用。硫化物抑制在N2O还原水平上更为显著；当不存在还原剂或Ti(III)时，[13N]N2是主要产物，而[13N]N2O在有硫化物存在时成为主要产物。结果表明，硫化物而非低氧化还原电位的特定作用导致反硝化细胞中NO还原受到部分抑制，N2O还原受到强烈抑制。
