Stefano Santabarbara

I graduated from University of Milan in 1999 and was awarded a Ph.D in plant biology in 2001. The main topic of my investigations was the mechanisms of damage and protection from high-light induced oxidative stresses. I then moves, as a post-doctoral research assistant to a joint research unit between Queen Mary and University CollegeLondon, where I studies the mechanisms of electron transfer in the Photosystem I reaction centres. Our investigations were pivotal in demonstrating the functionality of two parallel electron transfer chain in this reaction centre: a unique mechanism. I also proposed a molecular and thermodynamic explanation for the difference in electron transfer rates of these two active branches. Further on I moved, again as post doctoral researcher to Institut de Biologie Physico Chimique, in Paris. There we were able to confirm the functional asymmetry of the two functional branches in Photosystem I, demonstrate the presence of inter-quinone electron transfer in this reaction centre and to show how meta-stable intermediate control the fraction of electron transferred on each branch which is of crucial importance under bioenergetics evolutionary perspective. After a brief staying at Strathclyde university in Glasgow I returned to Milan as a researcher at the CNR in 2011. Currently I am group leader of the Photosynthetic Research Unit where our main focus is devoted to comparative studies of energy transfer and electron transport regulation in the Photosystems of divergent algal groups. Particular focus is devoted to the understanding of the mechanisms underlying the outstanding (near unit) quantum efficiency of these system, especially under limiting conditions determined by environmental shading and stresses. Most recently has been involved in demonstration that oxygenic photosynthesis can be operated with low energy Chlorophylls (d and/or f). This has important consequences in defining the minimal energy requirement for photosynthetic oxygen evolution, a key biological, evolutionary and environmental problem which is still open, and on which the laboratory is deeply involved. The laboratory is also active on the biotechnological exploitation of micro-algae, particularly green algae and cyanobacteria.

orcid://0000-0002-7993-2614,

Further collaborations:

- Anna Paola Casaza, IBBA-CNR, (Milan, Italy)
- Donatella Carbonera, Università di Padova (Padova, Italy)
- Bill Rutherford, Imperial College London (London)
- Alexey Yu. Semenov, Moscow State University (Moscow, Russia)
- Ryszard Jankowiak, Kansas State University, (Manhattan, USA)
- Ondrej Prasil, National Accademy of Sciences of Czech Republic (Trebon, Czech Republic)
- Christopher Duffy, Queen Mary University of London (London, Uk)
- Dennis Nuernberg, Freie Universitaet Berlin (Berlin, Germany)
- Petar Lambrev, Biological Research Centre (Szeged, Hungary)
- Wieslaw I Gruszecki, Univeristy of Lublin (Lublin, Poland)
- Stefano Caffarri, Aix-Marseille Université, (Marseille, France)
- Giulio Cerullo, Politecnico di Milano (Milan, Italy)

Key publications:

Sipka GB, Magyar M, Mezzetti A, Akhtar P, Zhu Q, Xiao Y, Han G, Santabarbara S, Shen JR, Lambrev PH, Garab G. Light-adapted charge-separated state of photosystem II: structural and functional dynamics of the closed reaction center. Plant Cell. 2021 33(4):1286-1302

Russo M, Casazza AP, Cerullo G, Santabarbara S, Maiuri M. Direct Evidence for Excitation Energy Transfer Limitations Imposed by Low-Energy Chlorophylls in Photosystem I-Light Harvesting Complex I of Land Plants. J Phys Chem B. 2021 125(14):3566-3573.

Reinot T, Jassas M, Kell A, Casazza AP, Santabarbara S, Jankowiak R . On wavelength-dependent exciton lifetime distributions in reconstituted CP29 antenna of the photosystem II and its site-directed mutants. J Chem Phys. 154(8):085101.

Remelli W, Santabarbara S. Excitation and emission wavelength dependence of fluorescence spectra in whole cells of the cyanobacterium Synechocystis sp. PPC6803: Influence on the estimation of Photosystem II maximal quantum efficiency. Biochim Biophys Acta Bioenergetics 2018 1859(11):1207-1222

Nürnberg DJ, Morton J, Santabarbara S, Telfer A, Joliot P, Antonaru LA, Ruban AV, Cardona T, Krausz E, Boussac A, Fantuzzi A, Rutherford AW. Photochemistry beyond the red limit in chlorophyll f-containing photosystems. Science. 2018 360(6394):1210-1213

Publications (21):

State transitions redistribute rather than dissipate energy between the two photosystems in Chlamydomonas
Nawrocki WJ, Santabarbara S, Mosebach L, Wollman FA, Rappaport F
Nature Plants, 2016
DOI: 10.1038/NPLANTS.2016.31

Carotenoid triplet states in photosystem II: Coupling with low-energy states of the core complex
Stefano Santabarbara, Alessandro Agostini, Anna Paola Casazza, Giuseppe Zucchelli, Donatella Carbonera
Biochimica et biophysica acta. Bioenergetics, 2015
DOI: 10.1016/j.bbabio.2014.11.008

A comparison between plant Photosystem I and Photosystem II architecture and functioning
Caffarri S.; Tibiletti T.; Jennings R.C.; Santabarbara S.
Current protein and peptide science (Print), 2014
DOI: 10.2174/1389203715666140327102218

Wavelength dependence of the fluorescence emission under conditions of open and closed Photosystem II reaction centres in the green alga Chlorella sorokiniana
Rizzo F.; Zucchelli G.; Jennings R.; Santabarbara S.
Biochimica et biophysica acta. Bioenergetics, 2014
DOI: 10.1016/j.bbabio.2014.02.009

Modulation of the fluorescence yield in heliobacterial cells by induction of charge recombination in the photosynthetic reaction center
Redding K.E.; Sarrou I.; Rappaport F.; Santabarbara S.; Lin S.; Reifschneider K.T.
Photosynthesis research (Print), 2014
DOI: 10.1007/s11120-013-9957-4

Photochemical trapping heterogeneity as a function of wavelength, in plant photosystem I (PSI-LHCI)
Jennings RC, Zucchelli G, Santabarbara S
Biochimica et biophysica acta. Bioenergetics, 2013
DOI: 10.1016/j.bbabio.2013.03.008

The requirement for carotenoids in the assembly and function of the photosynthetic complexes in Chlamydomonas reinhardtii.
Santabarbara S, Casazza AP, Ali K, Economou CK, Wannathong T, Zito F, Redding KE, Rappaport F, Purton S.
Plant physiology (Bethesda), 2013
DOI: 10.1104/pp.112.205260

Kinetics of phyllosemiquinone oxidation in the Photosystem I reaction centre of Acaryochloris marina
Santabarbara S, Bailleul B, Redding K, Barber J, Rappaport F, Telfer A
Biochimica et biophysica acta. Bioenergetics, 2012
DOI: 10.1016/j.bbabio.2011.10.003

Functional analyses of the plant photosystem I-light-harvesting complex II supercomplex reveal that light-harvesting complex II loosely bound to photosystem II is a very efficient antenna for photosystem I in state II.
Galka P, Santabarbara S, Khuong TT, Degand H, Morsomme P, Jennings RC, Boekema EJ, Caffarri S.
The Plant cell, 2012
DOI: 10.1105/tpc.112.100339

Exploring the electron transfer pathways in photosystem I by high-time-resolution electron paramagnetic resonance: observation of the B-side radical pair P700(+)A1B(-) in whole cells of the deuterated green alga Chlamydomonas reinhardtii at cryogenic temperatures.
Berthold T, von Gromoff ED, Santabarbara S, Stehle P, Link G, Poluektov OG, Heathcote P, Beck CF, Thurnauer MC, Kothe G.
Journal of the American Chemical Society (Print), 2012
DOI: 10.1021/ja208806g

Reconstituted CP29: multicomponent fluorescence decay from an optically homogeneous sample
Belgio E; Tumino G; Santabarbara S; Zucchelli G; Jennings RC
Photosynthesis research (Print), 2012
DOI: 10.1007/s11120-011-9696-3

The Q(y) Absorption Spectrum of the Light-Harvesting Complex II As Determined by Structure-Based Analysis of Chlorophyll Macrocycle Deformations
Zucchelli G; Santabarbara S; Jennings RC
Biochemistry (Easton), 2012
DOI: 10.1021/bi201677q

Phosphorescence study of chlorophyll d photophysics. Determination of the energy and lifetime of the photo-excited triplet state. Evidence of singlet oxygen photosensitization
Neverov KV, Santabarbara S, Krasnovsky AA Jr
Photosynthesis research (Print), 2011

Discrete redox signaling pathways regulate photosynthetic light-harvesting and chloroplast gene transcription
Allen JF, Santabarbara S, Allen CA, Puthiyaveetil S.
PloS one, 2011
DOI: 10.1371/journal.pone.0026372

Alteration of the H-bond to the A(1A) phylloquinone in Photosystem I: influence on the kinetics and energetics of electron transfer
Srinivasan N, Santabarbara S, Rappaport F, Carbonera D, Redding K, van der Est A, Golbeck JH.
The journal of physical chemistry. B, 2011
DOI: 10.1021/jp109531b

Interquinone Electron Transfer in Photosystem I As Evidenced by Altering the Hydrogen Bond Strength to the Phylloquinone(s).
Santabarbara S, Reifschneider,K, Jasaitis A, Gu FF, Agostini G , Carbonera D, Rappaport F, Redding KE.

Femtosecond to microsecond photochemistry of a [FeFe]hydrogenase enzyme model compound
Kaziannis S., Santabarbara S., Wright J.A., Greetham G.M., Towrie M., Parker A.W., Pickett C.J., Hunt N.T.

Directionality of electron-transfer reactions in Photosystem I of Prokaryotes: Universality of the bidirectional Electron-Transfer model
Santabarbara S., Kuprov I., Poluektov O., Casal A., Russel C.A., Purton S., Evans M.C.

Biocatalytic induction of supramolecular order
Hirst A.R., Roy S., Arora M., Das A.K., Hodson N., Murray P., Marshall S., Javid N., Sefcik J., Boekhoven J., Van Esch J.H., Santabarbara S., Hunt N.T., Ulijn R.V.
Nature chemistry (Print), 2010

Bidirectional Electron Transfer in the Reaction Centre of Photosystem I.
Santabarbara S., Galuppini L., Casazza A.P.
Journal of integrative plant biology (Print), 2010

Determination of the photolysis products of [FeFe]hydrogenase enzyme model systems using ultrafast multidimensional infrared spectroscopy.
Stewart AI, Wright JA, Greetham GM, Kaziannis S, Santabarbara S, Towrie M, Parker AW, Pickett CJ, Hunt NT.
Inorganic chemistry, 2010
DOI: 10.1021/ic101289s