title: Modeling culture profiles of the heterocystous N2-fixing cyanobacterium Anabaena flos-aquae.
abstract: Heterocyst differentiation is a unique feature of nitrogen-fixing cyanobacteria, potentially important for photobiological hydrogen production. Despite the significant advances in genetic investigation on heterocyst differentiation, there were no quantitative culture-level models that describe the effects of cellular activities and cultivation conditions on the heterocyst differentiation. Such a model was developed in this study, incorporating photosynthetic growth of vegetative cells, heterocyst differentiation, self-shading effect on light penetration, and nitrogen fixation. The model parameters were determined by fitting experimental results from the growth of the heterocystous cyanobacterium Anabaena flos-aquae CCAP 1403/13f in media without and with different nitrate concentrations and under continuous illumination of white light at different light intensities (2, 5, 10, 17, 20 and 50 microE m-2 s-1). The model describes the experimental profiles well and gives reasonable predictions even for the transition of growth from that on external N source to that via nitrogen fixation, responding to the change in external N concentrations. The significance and implications of the best-fit values of the model parameters are discussed.
authors.affiliation: Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, Ohio 44325-3906, USA.
authors.forename: Neissa M
authors.initials: NM
authors.lastname: Pinzon
authors.forename: Lu-Kwang
authors.initials: LK
authors.lastname: Ju
mesh_terms: D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques / Q000379:methods; D049109:Cell Proliferation / Q000528:radiation effects; D003198:Computer Simulation; D046869:Dolichospermum flos-aquae / Q000166:cytology* / Q000502:physiology* / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D008027:Light; D008954:Models, Biological; D009566:Nitrates / Q000378:metabolism*; D009586:Nitrogen Fixation / Q000502:physiology* / Q000528:radiation effects
chemical_list: D009566:Nitrates