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Research interests | The Keren Lab

Research interests

Photosynthetc organisms not only form the basis of the food chain but also form an integral part of the global carbon cycle. While photosynthesis is the most energy efficient transducton processes in nature, environmental conditons are ocen challenging in terms of light and nutrients. Our goal is to understand how photosynthetc organisms have evolved to meet these challenges. Our research is interdisciplinary and involves a wide range of methods from molecular biology to biochemistry and from to biophysics and biogeochemistry.

Nutrient Challenges: IRON

 

Iron (Fe) limits photosynthesis in one third of the oceans thus having a direct impact on global carbon cycles. Our research focuses on two main themes: Fe transport pathways into the cell. How do cells acquire the Fe they need? Fe homoeostasis within the cell. What are the cellular responses to transitons in iron availability?

Read more: Qiu et al. 2022, Schoffman and Keren 2019, Zer et al. 2018, Schoffman et al. 2016.

 

Iron Limitation experiment with freshwater and marine cyanobacteria

Extreme environments: DESERT CRUSTS

 

Cyanobacterial desert sand crusts are the foundation of desert ecosystems, stabilizing the sands and allowing further colonization. Desert cyanobacteria experience daily desiccation–hydration cycles, combined with high light intensities. In this project we elucidate the biophysical principles underlying photosynthesis under such extremes.

Read more: Choubeh et al. 2020, Bar Eyal et al. 2017, Bar Eyal et al. 2105Niedzwiedzki et al. 2023.

 

Streak camera time and spectra resolved fluorescence of hydrated and desiccated desert cyanobacteria

Light Dynamics: DEPTH

 

Organisms living in the water column must contend with changes in light intensity and quality with depth. We aim to understand acclimaton mechanisms which enables the efficiency and flexibility of photosynthesis under these conditons. 

Read more: Kolodny et al. 2022, Kolodny et al. 2020, Keren and Paltiel 2018

 

TEM of Deferentially light acclimated marine cyanobactria cells (Kolodny et al. 2020)