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.Electronic supplementary materialThe online version of this article (doi:10.1007/s11120-016-0329-8) contains supplementary material, which is available to authorized users.

A Novel Mechanism, Linked to Cell Density, Largely Controls Cell Division in Synechocystis

“…For the same reason, low cell viability could not account for the decrease in cell division. Our conclusion differs from that of Schuurmans et al (2017), who concluded that the transition to stationary phase is caused by nutrient limitation. However, the authors artificially stopped growth by bubbling cultures with nitrogen gas (N 2 ), which deprived cells of CO 2 and oxygen and, indeed, led to carbon starvation and growth arrest.…”

“…1; Supplemental Table S1). Schuurmans et al (2017) showed that a gradual increase of light intensity can lead cells to divide faster and avoid a linear phase. Based on this observation, the authors affirmed that the decrease of cell division from log to linear phase is caused solely by light limitation (self-shading).…”

Production of 1,2‐propanediol in photoautotrophic Synechocystis is linked to glycogen turn‐over

“…To elucidate how the recombinant genes influenced the physiology of the 1,2‐propanediol producing strain Synechocystis PG initial shaking flask experiments have been conducted. Growth phases were distinguished as described by Schuurmans (Schuurmans, Matthijs, and Hellingwerf (). Synechocystis PG and the wild type showed no significant differences in growth during the exponential, linear, and late growth phase (Figure a).…”

Global proteome response ofSynechocystis6803 to extreme copper environments applied to control the activity of the induciblepetJpromoter

“…; Schuurmans et al . ). For instance, enhanced production is obtained by metabolically active cells in the absence of growth (Berla et al .…”

“…However, synthesis of foreign compounds has been shown to compete with natural carbon partitioning in growing cells (Schuurmans et al . ; Giordano and Wang ). The carbon partitioning and product yields differ in various growth phases (Wang et al .…”