Space snacks made of bluegreen algae
Mysterious round-bellied bottles have been lined up in the Laboratory of Plant Physiology at the University of Turku. - We call them Mars bottles, says Kirsi Lehto, Adjunct Professor.
- The name comes from the bottles being used to simulate the atmospheric conditions on Mars. The planet?s atmosphere consists mainly of carbon dioxide and its pressure is only a fraction of that on Earth, explains Lehto.
The bottles are used to cultivate Spirulina, a subspecies of cyanobacteria, that is, blue-green algae. The cultivation is part of a research project led by Lehto, which studies whether Spirulina could help to solve some of the issues related to food and oxygen production on long space trips.
The interest in flying people to Mars has increased significantly recently, especially after the latest space probe observations made by the USA. Many technical problems have been solved in principle, but it will take a while for such a flight to be organised in practice.
Perhaps the weakest link in it all is the human being, who needs a great deal of oxygen for breathing and food as nourishment on a long space trip. It is impossible to carry all of the food needed from Earth: some of it has to be produced in the extreme conditions of space and perhaps even those of Mars.
Spirulina the miracle algae
Spirulina seems a promising space snack candidate, and it is now being studied around the world. In nature, it grows in tropical and subtropical waters, and millions of people in developing countries use the algae for food. In the West, powders and tablets made of Spirulina are popular and heavily marketed nutritional supplements, which are believed to have positive impacts on health that range from boosting the immune system to preventing cancer.
The nutritional content of Spirulina is exceptionally rich. Around 70 per cent of the algae consists of highly soluble proteins. Animal tests have shown Spirulina to be a sufficient source of proteins on its own. It contains around 20 per cent carbohydrates, but only ten per cent fats. Spirulina also contains a wide range of essential minerals, beta-carotene and various vitamins. Best of all, cultivation produces oxygen and sugar as by-products, which can be used to sustain life in space.
The ideal habitat of Spirulina is alkaline water with a temperature of 32?45 degrees centigrade. In these conditions the algae can produce a crop of 55 tonnes per hectare.
- However, Spirulina can withstand temperatures as high as 70 degrees and high levels of UV radiation, says Lehto.
Spirulina pasta for astronauts
According to Lehto, Spirulina is classified as being ?generally safe for consumption?, but it has been found to cause unpleasant side effects if consumed in large amounts. These include head and muscle ache, sweating and concentration problems. One of the main objectives of Lehto?s research team is to determine how different cultivation conditions affect the chemical properties of the algae and its utilisation as food.
- In our experiments, we cultivate different species of Spirulina in environments that vary in terms of, for example, temperature, light, UV radiation, carbon dioxide content and air pressure, says Lehto.
- We use cell biology methods to study the molecular processes involved in the algae?s adaptation to different habitats. The project aims to determine how the algae could be cultivated in extreme space conditions, as well as the impact of such conditions on the nutritional properties of Spirulina biomass.
A long-term objective is to examine whether the flavour and structure of Spirulina could be enhanced using, for example, genetic modification.
- Who knows, maybe future Mars astronauts will be feeding on Spirulina pasta made according to a Finnish recipe, says Kirsi Lehto, smiling.
Text: Timo Niitemaa
Photo: Vesa-Matti Väärä