Ciro Santilli @cirosantilli 35

Once upon a time a man paid me a visit in cyberspace, at this very domain. He planted a seed in our heads that would become the path we are walking today.

May 2011 was also the last time Satoshi communicated privately with other Bitcoin contributors. In an email that month to Martti Malmi, one of the earliest participants, Satoshi wrote, "I've moved on to other things and probably won't be around in the future."

One group, the Mycoplasma, comprises mostly parasites, many of which live inside other cells. Mycoplasma cells are tiny, with very small genomes. M. genitalium, discovered in 1981, has the smallest known genome of any bacterial cell, encoding fewer than  genes. Despite its simplicity, it ranks among the most common of sexually transmitted diseases, producing symptoms similar to Chlamydia infection. It is so small (less than a third of a micron in diameter, or an order of magnitude smaller than most bacteria) that it must normally be viewed under the electron microscope; and difficulties culturing it meant its significance was not appreciated until the important advances in gene sequencing in the early 1990s. Like Rickettsia, Mycoplasma have lost virtually all the genes required for making nucleotides, amino acids, and so forth. Unlike Rickettsia, however, Mycoplasma have also lost all the genes for oxygen respiration, or indeed any other form of membrane respiration: they have no cytochromes, and so must rely on fermentation for energy.