Navigation Links
What green algae are up to in the dark

How green algae produce hydrogen in the dark is reported by biologists at the Ruhr-Universitt Bochum in the "Journal of Biological Chemistry". Hereby, they have uncovered a mechanism for the production of the gas which has hardly been examined before; usually, researchers are interested in light-driven hydrogen synthesis. "Hydrogen could help us out of the energy crisis", says Prof. Dr. Thomas Happe, head of the working group Photobiotechnology. "If you want to make green algae produce more hydrogen, it is important to understand all the production pathways."

Green algae produce hydrogen under stress - even in the dark

Single-celled green algae of the type Chlamydomonas are microscopically small organisms: ten of them fit side by side on a human hair. In some ways, microalgae are not so very different from higher plants, such as trees. For example, they also perform photosynthesis. Unlike land plants, they can use light energy for the production of molecular hydrogen (H2). "However, Chlamydomonas and co only form hydrogen under stress", says Thomas Happe. "The disposal of the energy-rich gas serves as a kind of overflow valve so that excess light energy does not damage the sensitive photosynthetic apparatus." Chlamydomonas can also produce hydrogen in the dark. Although this fact has been known for decades, H2 synthesis in the absence of light has barely been studied because much less of the gas is produced in the dark than in the light. Moreover, it is complicated to isolate large quantities of the key enzyme of the dark-reaction, the so-called pyruvate:ferredoxin oxidoreductase. The RUB researchers nevertheless tackled the project.

Hydrogen production in the dark mimicked in vitro

Happe's team reconstructed the core of the dark hydrogen production in vitro, thus demonstrating the underlying mechanism. In order to get to the proteins involved, the researchers had these produced by bacteria. First they introduced the corresponding genes of the green algae into the gut bacterium Escherichia coli, for example, the gene for the pyruvate:ferredoxin oxidoreductase. E. coli then produced the proteins according to this blueprint. Happe's team isolated them from the bacterial cells and examined them like a construction kit. In the test tube, the biologists analysed how different combinations of proteins interacted with each other under specific environmental conditions.

"Ancient enzyme" discovered

In so doing, they found out that, under stress in the dark, the algae switch to a metabolic pathway which is normally only found in bacteria or single-celled parasites. "Chlamydmonas has an evolutionarily ancient enzyme", explains Jens Noth from the working group Photobiotechnology. "With the help of vitamin B1 and iron atoms, it gains energy from the breakdown of sugars." This energy is then used by other green algal enzymes, the hydrogenases, to form hydrogen. The unicellular microalgae switch on this metabolic pathway when they suddenly encounter oxygen-free conditions in the dark. Because, like humans, the green algae need oxygen to breathe if they cannot draw their energy from sunlight. The formation of hydrogen in the dark helps the cells to survive these stress condition. "With this knowledge, we have now found another piece of the puzzle to get an accurate picture of H2 production in Chlamydomonas", says Thomas Happe. "In future, this could also help to increase the biotechnologically relevant light-dependent H2 formation rate."

Contact: Prof. Dr. Thomas Happe
Ruhr-University Bochum

Related biology news :

1. Cities can reduce greenhouse gas emissions by 70 percent, says U of T researcher
2. New guide will allow electric utilities to develop Green Button Web tools
3. Aarhus University builds research station in North Greenland
4. In beef production, cow-calf phase contributes most greenhouse gases
5. Analysis of Greenland ice cores adds to historical record and provide glimpse into climates future
6. Toward reducing the greenhouse gas emissions of the Internet and telecommunications
7. Ancient red dye powers new green battery
8. Rice cultivates green batteries from plant
9. Fire and ice: Wildfires darkening Greenland snowpack, increasing melting
10. Greenphire CEO Sam Whitaker speaks on Sunshine Act and Clinical Trial Payments
11. An energy conscious workforce: New research looks at how to encourage staff to go green
Post Your Comments:
(Date:11/20/2015)... , November 20, 2015 ... company focused on the growing mobile commerce market and ... Gino Pereira , was recently interviewed on ... will air on this weekend on Bloomberg Europe ... America . --> NXTD ) ("NXT-ID" or ...
(Date:11/17/2015)... 17, 2015 Paris from ... --> Paris from 17 th until ... biometrics innovation leader, has invented the first combined scanner in ... same scanning surface. Until now two different scanners were required: ... can capture both on the same surface. This innovation ...
(Date:11/12/2015)... Nov. 12, 2015  A golden retriever that stayed ... dystrophy (DMD) has provided a new lead for treating ... the Broad Institute of MIT and Harvard and the ... . Cell, pinpoints a protective ... the disease,s effects. The Boston Children,s lab of ...
Breaking Biology News(10 mins):
(Date:12/1/2015)... Dr. Harry Lander , President of Regen, ... Chief Science Officer and recruits five distinguished scientists ... , President of Regen, expands his role to include ... five distinguished scientists to join advisory team --> ... to include serving as Chief Science Officer ...
(Date:11/30/2015)... ... ... Global Stem Cells Group announced that its scientific team is in the ... cells. The announcement starts a new phase toward launching the simple, quick system for ... lipoaspirate obtained from liposuction of excess adipose tissue. , Lipoaspirate, contains a large ...
(Date:11/30/2015)... Partnership includes an MPP licen ... niversity , s Solid Drug Nanoparticle (SDN) Technology ... up through cost cuts of priority ... licensees based anywhere in the world will have the right to make, use and ... , where licensees based anywhere in the world will have the right to make, ...
(Date:11/30/2015)... , ... November 30, 2015 , ... ... globally touring exhibition Jurassic World: The Exhibition, opening in March 2016 at Melbourne ... on a worldwide tour including several North American tour dates. The Exhibition is ...
Breaking Biology Technology: