Coherence in Oxygenic Photosynthesis

2014 ◽  
Author(s):  
Franklin D. Fuller ◽  
Jie Pan ◽  
Andrius Gelzinis ◽  
Vytautas Butkus ◽  
S. Seckin Senlik ◽  
...  
Keyword(s):  
Oxygenic Photosynthesis

scholarly journals Cyanobakterien als Biokatalysatoren

BIOspektrum ◽  
2021 ◽  
Vol 27 (2) ◽  
pp. 208-210
Author(s):  
Marc M. Nowaczyk ◽  
Hanna C. Grimm ◽  
Leen Assil-Companioni ◽  
Robert Kourist
Keyword(s):  
Natural Process ◽  
Oxygenic Photosynthesis ◽  
Phototrophic Microorganisms ◽  
Electron Sink ◽  
Pcc 6803

AbstractThe highly optimized natural process of oxygenic photosynthesis leads to the formation of redox equivalents, such as NADPH, that can be used to fuel heterologous biotransformations in phototrophic microorganisms. We investigated the reduction of 2-methylmaleimide by the ene-reductase YqjM in the cyanobacterium Synechocystis sp. PCC 6803 and doubled the productivity of the cells by inactivating flavodiironproteins (FDPs) as competing electron sink under self-shading conditions, reaching 18.3 mmol h−1 L−1.

scholarly journals Recovery of Unicellular Cyanobacteria from Nitrogen Chlorosis: A Model for Resuscitation of Dormant Bacteria

2021 ◽  
pp. 1-10
Author(s):  
Niels Neumann ◽  
Sofia Doello ◽  
Karl Forchhammer
Keyword(s):  
Nitrogen Starvation ◽  
Oxygenic Photosynthesis ◽  
Cellular Activity ◽  
Input Output ◽  
Minimal Set ◽  
Operation System ◽  
Developmental Transitions ◽  
The Awakening ◽  
Output System ◽  
Basic Input

Nitrogen starvation induces developmental transitions in cyanobacteria. Whereas complex multicellular cyanobacteria of the order Nostocales can differentiate specialized cells that perform nitrogen fixation in the presence of oxygenic photosynthesis, non-diazotrophic unicellular strains, such as <i>Synechococcus elongatus</i> or <i>Synechocystis</i> PCC 6803, undergo a transition into a dormant non-growing state. Due to loss of pigments during this acclimation, the process is termed chlorosis. Cells maintain viability in this state for prolonged periods of time, until they encounter a useable nitrogen source, which triggers a highly coordinated awakening process, termed resuscitation. The minimal set of cellular activity that maintains the viability of cells during chlorosis and ensures efficient resuscitation represents the organism’s equivalent of the BIOS, the basic input/output system of a computer, that helps “booting” the operation system after switching on. This review summarizes the recent research in the resuscitation of cyanobacteria, representing a powerful model for the awakening of dormant bacteria.

scholarly journals Antioxidant and Signaling Role of Plastid-Derived Isoprenoid Quinones and Chromanols

2021 ◽  
Vol 22 (6) ◽  
pp. 2950
Author(s):  
Beatrycze Nowicka ◽  
Agnieszka Trela-Makowej ◽  
Dariusz Latowski ◽  
Kazimierz Strzalka ◽  
Renata Szymańska
Keyword(s):  
Current Knowledge ◽  
Stress Factors ◽  
Oxygenic Photosynthesis ◽  
Ros Generation ◽  
Main Site ◽  
Storage Lipids ◽  
Abiotic Stress Factors ◽  
Cell Components ◽  
And Function

Plant prenyllipids, especially isoprenoid chromanols and quinols, are very efficient low-molecular-weight lipophilic antioxidants, protecting membranes and storage lipids from reactive oxygen species (ROS). ROS are byproducts of aerobic metabolism that can damage cell components, they are also known to play a role in signaling. Plants are particularly prone to oxidative damage because oxygenic photosynthesis results in O2 formation in their green tissues. In addition, the photosynthetic electron transfer chain is an important source of ROS. Therefore, chloroplasts are the main site of ROS generation in plant cells during the light reactions of photosynthesis, and plastidic antioxidants are crucial to prevent oxidative stress, which occurs when plants are exposed to various types of stress factors, both biotic and abiotic. The increase in antioxidant content during stress acclimation is a common phenomenon. In the present review, we describe the mechanisms of ROS (singlet oxygen, superoxide, hydrogen peroxide and hydroxyl radical) production in chloroplasts in general and during exposure to abiotic stress factors, such as high light, low temperature, drought and salinity. We highlight the dual role of their presence: negative (i.e., lipid peroxidation, pigment and protein oxidation) and positive (i.e., contribution in redox-based physiological processes). Then we provide a summary of current knowledge concerning plastidic prenyllipid antioxidants belonging to isoprenoid chromanols and quinols, as well as their structure, occurrence, biosynthesis and function both in ROS detoxification and signaling.

scholarly journals Cyanobacterial psbA gene family: optimization of oxygenic photosynthesis

2009 ◽  
Vol 66 (23) ◽  
pp. 3697-3710 ◽  
Author(s):  
Paula Mulo ◽  
Cosmin Sicora ◽  
Eva-Mari Aro
Keyword(s):  
Gene Family ◽  
Oxygenic Photosynthesis ◽  
Psba Gene

Validating the predictions of murburn model for oxygenic photosynthesis: Analyses of ligand-binding to protein complexes and cross-system comparisons

2021 ◽  
pp. 1-33
Author(s):  
Kelath Murali Manoj ◽  
Daniel Andrew Gideon ◽  
Abhinav Parashar ◽  
Vijay Nirusimhan ◽  
Pushparaj Annadurai ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Protein Complexes ◽  
Oxygenic Photosynthesis ◽  
Cross System
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