[Australia] Next time you’re lying on the beach soaking up the rays, spare a thought for the sun-loving algae hiding in the grains of sand beneath you.
By lying on the sand you are denying these critters sunlight, and to survive the microalgae have to hold their collective breath until they see the light again.
Sand is full of microalgae called diatoms. The algae can survive in harsh environments – ones in which it is continuously churned by the sea or covered by sunbathers. The algae are nothing if not adaptive: they can be at the top of the pile soaking up light one minute and buried in the dark the next.
Now Monash University researchers have found that the microscopic algae living in sand from Middle Park beach are an unlikely source of hydrogen gas, a key ingredient for those developing clean energy alternatives.
“Here we have sand producing a fuel source and all we have to do is let them be in the sun for a little bit,” biogeochemist Michael Bourke said.
Each grain of beach sand would host hundreds of microalgae – with each producing carbon dioxide and hydrogen gas as a result of a process called dark fermentation, which the microalgae undertake to survive.
With colleague Perran Cook, Mr Bourke established that the algae found in beach sand ferments – just as yeast does in alcohol.
This dark fermentation process, unknown in sand before the research was published, could prove useful in developing the next generation of biofuels because the byproduct is hydrogen gas.
Hydrogen gas is seen as a clean fuel source because, unlike petroleum, it only produces water when burnt.
Dark fermentation has been studied and observed in laboratory experiments but this is the first time it has been seen occurring naturally in sand on a beach.
“One of the reasons why we are so excited about it is because this process is happening to such a great extent,” Mr Bourke said.
The microalgae produce hydrogen gas in large quantities but whether it could be produced on an industrial scale is still to be established.
Mr Bourke said he expected the microalgae found in the sand from Middle Park beach, known as green alga and diatoms, would likely be found in beach sand from around the world. He said the hydrogen gas-producing critters also live in soil.
The research has been published in the journal Nature Geoscience.
Photo: Michael Bourke with sand at Middle Park beach. Each grain of sand would host hundreds of micro-algae. Photo: Joe Armao
View original article at: Sun-loving sand critters found on Melbourne beach could power future green energy