|Huete-Ortega M, Di Marcello M, Iglesias-Gonzalez J, Gnaiger E (2020) High-resolution respirometry for chloroplast and mitochondrial bioenergetics in Chlamydomonas reinhardtii ― towards biotechnology exploitations. https://doi.org/10.26124/mitofit:ea20.algaeurope.0001|
» MitoFit Preprint Arch EA20.1.
Abstract: Version 1 (v1) 2020-11-30 doi:10.26124/mitofit:ea20.algaeurope.0001
Chloroplast and mitochondrial bioenergetic control of algal growth and metabolite production is necessary to maintain metabolic integrity. In contrast to mammalian cells, algal mitochondria express alternative oxidases (AOX), which divert electron transfer from coenzyme Q (Q) away from cytochrome c oxidase (Complex IV, CIV) . In algae, therefore, we distinguish between respiration through the Q-AOX and Q-CIV branches of the electron transfer system. A better understanding of the contribution of both branches to mitochondrial dark respiration is required to optimize algal biomass and metabolite production for biotechnological purposes. High-resolution respirometry (HRR; Oroboros O2k) is widely used to assess mitochondrial respiration and other bioenergetic parameters in the biomedical field of mitochondrial and cell research . In our interdisciplinary study, we introduced a new method of studying oxygen kinetics [3,4] for the partitioning of dark respiration between the Q-AOX and Q-CIV branches in Chlamydomonas reinhardtii grown for biomass and lipid production . This method is based on the distinct oxygen affinities of these enzymes. In addition, the multimodal approach of the Oroboros O2k was extended using the novel PhotoBiology-Module of the NextGen-O2k for determining the maximum light-saturated and inorganic carbon-saturated photosynthesis rates [6,7]. This methodology allows for increasing our current knowledge of the bioenergetics of chloroplasts and mitochondria, which is of particular importance for biotechnological exploitations. This communication is part of the NextGen-O2k project that has received funding from the European Union’s Horizon 2020 research and innovation program under the grant agreement No 859770.
• Keywords: photosynthesis, respiration, microalgae, high-resolution respirometry, O2 kinetics, NextGen • Bioblast editor: Huete-Ortega Maria
- Young L, Shiba T, Harada S, Kita K, Albury MS, Moore AL (2013) The alternative oxidases: simple oxidoreductase proteins with complex functions. Biochem Soc Trans 41:1305-11.
- Doerrier C, Garcia-Souza LF, Krumschnabel G, Wohlfarter Y, Mészáros AT, Gnaiger E (2018) High-Resolution FluoRespirometry and OXPHOS protocols for human cells, permeabilized fibers from small biopsies of muscle, and isolated mitochondria. Methods Mol Biol 1782:31-70.
- Meszaros AT, Haider M, Di Marcello M, Gnaiger E (2018) High-resolution mitochondrial oxygen kinetics as diagnostic tool in Complex IV impairments. Abstract Mitochondrial Medicine 2018 Hinxton UK.
- Di Marcello M, Iglesias-Gonzalez J, Meszaros AT, Haider M, Gnaiger E, Huete-Ortega M (2019) Partitioning between cytochrome c oxidase and alternative oxidase studied by oxygen kinetics of dark respiration in Chlamydomonas reinhardtii: a microalgae model organism. MitoFit Preprint Arch doi:10.26124/mitofit:ea19.MiPSchool.0005.v3
- Pulz O, Gross W (2004) Valuable products from biotechnology of microalgae. App Microbiol Microbiol Biotech 65:635-48.
- Giordano M, Pezzoni V, Hell R (2000) Strategies for the allocation of resources under sulfur limitation in the green alga Dunaliella salina. Plant Physiol 124:857-64.
- Palmqvist K, Ögren E, Lernmark U (1994) The CO2-concentrating mechanism is absent in the green alga Coccomyxa: a comparative study of photosynthetic CO2 and light responses of Coccomyxa, Chlamydomonas reinhardtii and barley protoplasts. Plant Cell Envir 17:65-72.
- Went N, Di Marcello M, Gnaiger E (2021) Oxygen dependence of photosynthesis and light-enhanced dark respiration studied by High-Resolution PhotoRespirometry. MitoFit Prep 2021.5. - »Bioblast link«
Preprints for Gentle Science
Labels: MiParea: Instruments;methods
Preparation: Intact cells Enzyme: Complex IV;cytochrome c oxidase Regulation: Oxygen kinetics Coupling state: ROUTINE Pathway: Other combinations HRR: Oxygraph-2k, NextGen-O2k
Chlamydomonas, Preprints, Dark respiration, Photosynthesis, PB-Module, MitoFit 2021.5 PB