Physiological basis for nitrogen fixation in Cylindrospermopsis raciborskii strain CS-505 : an invasive, toxin-producing cyanobacterium that has radiated from tropical to temperate regions worlwide.
Loading...
Files
Date
2013
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Cyanobacteria are known for their ability to fix carbon and get energy through photosynthesis. Furthermore, some cyanobacteria are capable of fixing N2 when its environment lacks sources of combined nitrogen (diazotrophy). Because the enzyme that converts N2 to NH4 (nitrogenase) is irreversibly inactivated by atmospheric concentrations of O2, diazotrophic cyanobacteria must separate this process from photosynthesis, temporarily (e.g. by fixing N2 in the dark phase of the photoperiod) or generating a micro-oxic environment for nitrogenase. Thus, some multicellular cyanobacteria, which grow forming filamentous structures called trichomes, can differentiate specialized cells to fix N2 (heterocysts) when grown diazotrophically. Most studies have focused on cyanobacteria that differentiate intercalary heterocysts among the vegetative cells of their trichomes. Contrary, this thesis characterized the diazotrophic acclimatization strategy of a cyanobacterium that differentiates heterocysts only at the ends of its trichomes (terminal heterocysts): Cylindrospermopsis raciborskii strain CS-505.
Description
Tesis (Doctor en Ciencias Biológicas, mención Genética Molecular y Microbiología)--Pontificia Universidad Católica de Chile, 2013