Upper temperature limits for growth and diazotrophy in the thermophilic cyanobacterium HTF Chlorogloeopsis
| Autor: | Jens Kirk Thomsen, Raymond P. Cox |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1993 |
| Předmět: |
Cyanobacteria
food.ingredient biology Nitrogenase chemistry.chemical_element Chlorogloeopsis General Medicine Photosynthesis biology.organism_classification Biochemistry Microbiology Anoxic waters Nitrogen food chemistry Environmental chemistry Genetics Nitrogen fixation Diazotroph Molecular Biology |
| Zdroj: | Cox, R P & Thomsen, J K 1993, ' Upper temperature limits for growth and diazotrophy in the thermophilic cyanobacterium HTF Chlorogloeopsis ', Archives of Microbiology, vol. 159, no. 5, pp. 423-427 . https://doi.org/10.1007/bf00288588 |
| DOI: | 10.1007/bf00288588 |
| Popis: | The effect of temperature and oxygen on diazotrophic growth of the thermophilic cyanobacterium HTF (High Temperature Form) Chlorogloeopsis was investigated using cells grown in light-limited continuous culture at a dilution rate of 0.02 h-1. Diazotrophy was more sensitive to elevated temperatures than growth with combined nitrogen. The maximum temperature for growth of cultures gassed with CO2-enriched air was more than 55 °C but less than 60 °C with N2 as the sole nitrogen source, but between 60°C and 65°C when nitrate was present in the medium. The effect of temperature on nitrogenase activity, photosynthesis and respiration in the dark was determined using cells grown at 55°C. Maximal rates of all three processes were observed at 55°C and rates at 60°C during shortterm incubations were not less than 75% of the maximum. However, nitrogenase activity at 60°C was unstable and decayed at a rate of 2.2 h-1 under air and at 0.3 h-1 under argon. Photosynthesis and respiration were more stable at 60°C than anoxic nitrogen fixation. The upper temperature limits for diazotrophic growth thus seem to be set by the stability of nitrogenase. |
| Databáze: | OpenAIRE |
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