Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Algae in darkness – Survival strategy unraveled

The world’s oceans teem with unicellular algae that carry out photosynthesis in the sunlight.

It has been known for a while that the particularly abundant diatoms (unicellular algae with a silicate frustule) are also able to survive in the dark bottom of the ocean, where neither photosynthesis nor respiration with oxygen is possible. Scientists of the Max Planck Institute for Marine Microbiology now disclose this artifice of the algae in the journal Proceedings of the National Academy of Sciences: In darkness, the diatoms breathe with nitrate in place of oxygen.

Laser-scanning-fluorescence image of the marine diatom Amphora coffeaeformis. Red: auto-fluorescing chloroplasts, green: lipid membranes (stained with MDY-64). Martin Beutler, bionsys GmbH, Bremen, Germany (

Microalgae often measure only a few hundredths of a millimeter, but due to their vast abundance in the world’s oceans they are responsible for about 40% of the marine primary production, i.e., the biomass production via carbon dioxide fixation in the sunlight. They often appear as massive blooms near the sea surface or as greenish-brownish meadows on the sea floor, if still reached by sunlight. However, diatoms (unicellular algae with a silicate frustule) are also able to survive in the absence of sunlight and oxygen, for instance, buried in the sea floor.

Anja Kamp, Dirk de Beer, Jana L. Nitsch, Gaute Lavik, and Peter Stief, scientists at the Max Planck Institute for Marine Microbiology in Bremen cultivated several diatom species in the laboratory to explore the metabolic process that allows the tiny algae to survive in darkness. A correlation was found between the nitrate that is stored by a diatom cell and its ability to survive in the absence of sunlight and oxygen. The more nitrate the cell contained, the longer it could survive in darkness where the cell does not have the possibility to produce oxygen via photosynthesis for its own respiration. In experiments with the coffee-bean-shaped diatom Amphora coffeaeformis, the scientists proved that diatoms use the nitrate stored in their cells for respiration in the absence of oxygen. Within just one day, most of the stored nitrate is used up, converted to ammonium, and excreted by the cell.

A key finding of the Max-Planck scientists was that diatoms use nitrate just for respiration rather than for biomass production, as would be the case in sunlight. Anja Kamp says: “The rapid consumption of nitrate and the absence of biomass production tell us that nitrate respiration in diatoms is a metabolic process that only serves to prepare the cell for a resting stage and therefore nitrate respiration is not sustained for longer time periods.”

In bacteria, nitrate respiration in the absence of oxygen is nothing exceptional, as many of the bacteria studied at the Max-Planck-Institute are able to breathe with nitrate, sulfate, or even iron compounds. It is more spectacular to discover that algae, i.e., organisms with a cell nucleus, are able carry out both photosynthesis and nitrate respiration, each under different environmental conditions. These results have just been published in the renowned interdisciplinary journal Proceedings of the National Academy of Sciences.

Further inquiries to:
Dr. Anja Kamp; Phone: +49 421 2028 856;
or to the press officer:
Dr. Manfred Schlösser; Phone: +49 421 2028 704;
Original article:
Diatoms respire nitrate to survive dark and anoxic conditions. Anja Kamp, Dirk de Beer, Jana L. Nitsch, Gaute Lavik, and Peter Stief. Proceedings of the National Academy of Sciences of the United States of America. doi:10.1073/pnas.1015744108

Dr. Manfred Schloesser | Max-Planck-Institut
Further information:

More articles from Life Sciences:

nachricht Mitochondria control stem cell fate
27.10.2016 | Technische Universität München

nachricht How a fungus inhibits the immune system of plants
27.10.2016 | Julius-Maximilians-Universität Würzburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

The gene of autumn colours

27.10.2016 | Life Sciences

Polymer scaffolds build a better pill to swallow

27.10.2016 | Life Sciences

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>