How does sand hold its breath?

Not much lives in the sand, you say?

Actually, sand contains millions and millions of algae organisms called diatoms. They are a highly productive and vital food source for other organisms near water.

But how do these organisms survive being constantly turned over, buried with no oxygen, and resurfaced again?

The Study

Researchers at Monash University’s Water Studies Centre have been examining stretches of beach in Melbourne, Australia to discover how.

“This is a new mechanism by which this type of algae survive under these conditions… our work has found that they ferment, like yeast ferments sugar to alcohol. In this case, the products are hydrogen and ‘fats’, for example, oleate, which is a component of olive oil.” – Associate Professor Cook – lead author in the study

The team combined flow-through reactor experiments with microbiological approaches to find the dominant contributors and pathways of dissolved inorganic carbon production in permeable sediments.

They were able to show that dark fermentation is the dominant metabolic pathway and mechanism that algae survive in sand.

“The finding that hydrogen is a by-product of this metabolism has important implications for the types of bacteria present in the sediment… It is well known that bacteria in the sediment can ‘eat’ hydrogen, however, these hydrogen eating bacteria may be more common than we previously thought.” – Associate Professor Cook.

Needless to say, there is more to the beach than we think.

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