ROQUETTE FACTORY, KLOTZE, GERMANY
In the 1300s, Aztec fishermen skimmed blue-green algae from Lake Texcoco in Mexico and dried it to make cakes that they ate with corn or spicy sauces. Today, microalgae destined for nutritional powders and tablets are grown in tubular aquariums watched over by white-coated workers. At the Roquette factory in Germany, there are 500km of narrow glass growing tubes. These ensure maximum exposure to sunlight, enabling the algae to grow faster than in the depths of a murky pond. Touted as superfoods, microalgae such as spirulina and Chlorella are densely packed with protein, as well as compounds such as polyunsaturated fatty acids and sterols, which guard against heart disease and other conditions. This worker is surveying tubes filled with Odontella aurita, cultivated for its carotenoid content – it makes fucoxanthin, a pigment shown to kill cancer cells in the test tube.