by Gemma Reguera — Famed as­tronomer and writer Carl Sagan said in his book Cos­mos: "The ni­tro­gen in our DNA, the cal­cium in our teeth, the iron in our blood, the car­bon in our ap­ple pies were made in the in­te­ri­ors of col­laps­ing stars. We are made of starstuff." And so are mi­crobes, we must…