Diatoms – the jewels of the ocean
Diatoms are unicellular microscopic algae, with cell walls consisting of silicon dioxide. The cell wall has a very specific pattern of tiny pores, allowing exchange of nutrients and waste products. Each pattern is species specific. It is no surprise that diatoms are referred to as ocean jewels.
Fossils indicate that diatoms have existed for at least 200 million years. The number of diatom species is estimated to around 20 000 – 2 000 000. New species are continuously identified and described.
Place in the ecosystem
Our every fourth breath of oxygen comes from diatoms. They form the basis of the food web and are eaten by everything from the size of microscopic ciliates to large whales.
Where to be found
Diatoms are to be found everywhere where there is moist and some available light: in the ocean, on the seabed, in lakes, in and on ice – even on cave walls!
Diatoms photosynthesize, but they are also able to uptake small organic molecules. Thus, they can survive in darkness without forming resting stages. Diatoms contain chlorophyll a and c and, in addition, different carotenoids such as fucoxanthin, which give them a brownish colour. They store energy in the form of oil (lipids) and a carbohydrate called chrysolaminarin.
At the service of humans
The frustules of the algae have one to three layers of nanopores, which can be used in several industrial applications. This frustle material can be used to increase the efficiency of solar panels due to the structures light trapping property. The structure also blocks block UV light efficiently which can be utilized in e.g. sunscreens and plastics. Due to the materials nanoporosity it also takes up and releases chemical substances efficiently which can be utilized in a lot of different applications. . The oil produced by diatoms is excellent for use in fish feed production or even food supplements due to the content of polyunsaturated fatty acids.
When diatoms grow (increase in number), they capture carbon dioxide, nitrogen and phosphorous, thus, our algae cultures become a perfect combination of a trap of greenhouse gases and waste water treatment.