Measurement of chemoautotrophic CO2assimilation in marine nitrifying bacteria: an enzymatic approach

✍ Scribed by H. E. Glover

• Publisher: Springer-Verlag
• Year: 1983
• Tongue: English
• Weight: 587 KB
• Volume: 74
• Category: Article
• ISSN: 0025-3162
• DOI: 10.1007/bf00403454

✦ Synopsis

Enzyme activities of ribulose-l,5-bisphosphate carboxylase (RUBPCase) and chemoautotrophic CO2 fixation were measured during batch growth of six marine nitrifying bacteria. The NH4-oxidizer Nitrosococcus oceanus and the NOz-oxidizer Nitrococcus mobilis were also examined during exponential growth at different temperatures, 02 tensions and nitrogen-limited growth rates. Cellular activities of RUBPCase and rates of CO2 fixation varied with age in batch culture, temperature, 02 tension and nitrogen limitation, but there was a significant positive correlation between both parameters. Below 26~ the ratio of CO2 fixation:RUBPCase did not vary significantly with cellular physiological state. Ratios of Chemoautotrophic CO2 fixation:RUBCase activity for the six nitrifiers indicated that the ratio was species dependent. Three NQ-oxidizers had a significantly lower CO2 to enzyme ratio than three NH4-oxidizers.