Ammonia and O2uptake in relation to proton translocation in cells ofNitrosomonas europaea

✍ Scribed by Basant Bhandari; D. J. D. Nicholas

• Book ID: 104762965
• Publisher: Springer
• Year: 1979
• Tongue: English
• Weight: 578 KB
• Volume: 122
• Category: Article
• ISSN: 0302-8933
• DOI: 10.1007/bf00411287

✦ Synopsis

The uptake of ammonia and 02 by washed cells of Nitrosomonas has been followed simultaneously and continuously using electrode techniques. The stoichiometry of NH2 oxidation, 02 uptake and NO2 production was I : 1.5 : 1.0 and for NHzOH oxidation a ratio of 1 for O2 :NO2. A variety of inhibitors of electron transport and metals as well as uncouplers restricted ammonia uptake more markedly than O 2 utilization. There is good evidence for the involvement of copper in the NH2 uptake process.

A quinacrine fluorescence technique has been used to study the proton extrusion by washed cells on adding NH4C1 and NHzOH respectively as substrates. The uptake of NH + was followed by the extrusion of H + and this process was depressed by those inhibitors which were also effective in the electrode experiments. A requirement for copper is also established for the translocation of protons into the medium, resulting from the uptake of NH2 by cells.