It was this very same blue-green algae that created the oxygen they are now breathing.

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The organisms do not fit easily into our classification schemes, though in some respects they resemble blue-green algae.

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And UC Davis researchers figured out a way to engineer blue-green algae to make fuel from sunlight.

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While analysis of spirulina has shown that it does not contain a harmful toxin called microcystin, other blue-green algae has found to be frequently contaminated.

BBC: Algae may boost immune system

Event bosses have been forced to cancel the Great North Swim in Cumbria after blue-green algae was found in the water which could be dangerous.

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We were surprised to learn that a biologist at the Argonne National Laboratory is transforming the data found in blue-green algae into music, while researchers at Michigan State discovered that super-strong bacteria can produce nuggets of gold.

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In May 2000, the Oregon Department of Health surveyed 87 samples of non-spirulina blue green algae, finding that 63 had microcystin levels above the regulatory limit.

BBC: Algae may boost immune system