3 years ago

Metabolic Flexibility Underpins Growth Capabilities of the Fastest Growing Alga

Metabolic Flexibility Underpins Growth Capabilities of the Fastest Growing Alga
Ilana Rogachev, Doron Eisenstadt, Antonio F. Tiburcio, Jedrzej Szymanski, Aaron Kaplan, Joachim Kopka, Sagit Meir, Isaac Kedem, Isabel Orf, Asaph Aharoni, Haim Treves, Nir Keren, Rubén Alcázar, Omer Murik


The factors rate-limiting growth of photosynthetic organisms under optimal conditions are controversial [1–8]. Adaptation to extreme environments is usually accompanied by reduced performance under optimal conditions [9, 10]. However, the green alga Chlorella ohadii, isolated from a harsh desert biological soil crust [11–17], does not obey this rule. In addition to resistance to photodamage [17, 18], it performs the fastest growth ever reported for photosynthetic eukaryotes. A multiphasic growth pattern (very fast growth [phase I], followed by growth retardation [phase II] and additional fast growth [phase III]) observed under constant illumination and temperature indicates synchronization of the algal population. Large physiological changes at transitions between growth phases suggest metabolic shifts. Indeed, metabolome analyses at points along the growth phases revealed large changes in the levels of many metabolites during growth with an overall rise during phase I and decline in phase II. Multivariate analysis of the metabolome data highlighted growth phase as the main factor contributing to observed metabolite variance. The analyses identified putrescine as the strongest predictive metabolite for growth phase and a putative growth regulator. Indeed, extracellular additions of polyamines strongly affected the growth rate in phase I and the growth arrest in phase II, with a marked effect on O2 exchange. Our data implicate polyamines as the signals harmonizing metabolic shifts and suggest that metabolic flexibility enables the immense growth capabilities of C. ohadii. The data provide a new dimension to current models focusing on growth-limiting processes in photosynthetic organisms where the anabolic and catabolic metabolisms must be strictly regulated.

Publisher URL: http://www.cell.com/current-biology/fulltext/S0960-9822(17)30872-2

DOI: 10.1016/j.cub.2017.07.014

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.