title: Transition from exponential to linear photoautotrophic growth changes the physiology of Synechocystis sp. PCC 6803.
abstract: Phototrophic microorganisms like cyanobacteria show growth curves in batch culture that differ from the corresponding growth curves of chemotrophic bacteria. Instead of the usual three phases, i.e., lag-, log-, and stationary phase, phototrophs display four distinct phases. The extra growth phase is a phase of linear, light-limited growth that follows the exponential phase and is often ignored as being different. Results of this study demonstrate marked growth phase-dependent alterations in the photophysiology of the cyanobacterium Synechocystis sp. PCC 6803 between cells harvested from the exponential and the linear growth phase. Notable differences are a gradual shift in the energy transfer of the light-harvesting phycobilisomes to the photosystems and a distinct change in the redox state of the plastoquinone pool. These differences will likely affect the result of physiological studies and the efficiency of product formation of Synechocystis in biotechnological applications. Our study also demonstrates that the length of the period of exponential growth can be extended by a gradually stronger incident light intensity that matches the increase of the cell density of the culture.
authors.affiliation: Molecular Microbial Physiology Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: R M
authors.initials: RM
authors.lastname: Schuurmans
authors.affiliation: Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: J C P
authors.initials: JC
authors.lastname: Matthijs
authors.affiliation: Molecular Microbial Physiology Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands. K.J.Hellingwerf@uva.nl.
authors.forename: K J
authors.initials: KJ
authors.lastname: Hellingwerf
mesh_terms: D052818:Autotrophic Processes; D001426:Bacterial Proteins / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D002734:Chlorophyll / Q000737:chemistry / Q000378:metabolism; D000077194:Chlorophyll A; D005453:Fluorescence; D015964:Gene Expression Regulation, Bacterial; D045524:Phycobilisomes / Q000378:metabolism; D010971:Plastoquinone / Q000378:metabolism; D012333:RNA, Messenger; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism; D046939:Synechocystis / Q000254:growth & development / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D045524:Phycobilisomes; D012333:RNA, Messenger; D002734:Chlorophyll; D002244:Carbon; D012273:Ribulose-Bisphosphate Carboxylase; D010971:Plastoquinone; D000077194:Chlorophyll A
keywords: Batch culture; Cyanobacteria; Molecular physiology; PSI/PSII ratio; State transition