Biosciences researchers are among the recipients of four new DOE awards. Two awards will focus on reducing carbon emissions while producing bioenergy. The other two are aimed at understanding the role of microbiomes in the biogeochemical cycling of elements like carbon.
In the latest episode of JGI’s monthly podcast, Genome Insider, Alison Takemura interviews Setsuko Wakao and Kris Niyogi, biologists at UC Berkeley and in Berkeley Lab’s Molecular Biophysics and Integrated Bioimaging (MBIB) Division. In this 20-minute episode, they discuss their research on a tiny group of algae with insanely gorgeous exterior shells.
Using a forward genetics approach, a team of Biosciences researchers revealed that the enzyme hexokinase (HXK1), which is involved in sugar metabolism in organisms ranging from bacteria to plants to humans, is necessary for the regulation of photosynthesis and metabolism in the green alga Chromochloris zofngiensis. Kris Niyogi, a faculty scientist in Molecular Biophysics and Integrated Bioimaging (MBIB), was senior author on the paper, published in Nature Communications Biology.
The unicellular green alga Chromochloris zofingiensis has the ability to shift metabolic modes from photoautotrophic (synthesizing food using light as energy source) to heterotrophic (obtaining food and energy from exogenous sources) in response to carbon source availability in the light. It also has the capacity—under certain conditions—to produce high amounts of commercially relevant bioproducts: notably, the ketocarotenoid astaxanthin, used in feed, cosmetics, and as a nutraceutical, and triacylglycerol (TAG) biofuel precursors.
Understanding how photosynthesis and metabolism are regulated in algae could, via bioengineering, enable scientists to reroute metabolism toward beneficial bioproducts for energy, food, and human health. To that end, Berkeley Lab Biosciences researchers used C. zofingiensis as a simple algal model system to investigate conserved eukaryotic sugar responses, as well as mechanisms of thylakoid breakdown and biogenesis in chloroplasts.
Using cryo-electron microscopy (cryo-EM), which allows an unprecedented level of resolution, Biosciences researchers compared the structure of photosystem I in the moss Physcomitrella patens with its structure in the small flowering land plant Arabidopsis thaliana, and in the green alga Chlamydomonas reinhardtii. Because moss evolved after algae but before vascular land plants, such comparisons can shed light on how plants evolved to move from the ocean to land.