Sarah Richardson, a biologist, dreams of being of a farmer. Instead of tending to barns full of cows making milk, she'll have petri dishes full of bacteria. They'll be making a brand new kind of fuel that could replace gas we put in our cars. But just like the first human to milk a cow, Sarah has a difficult job to do. In this episode, she explains how she's trying to convince bacteria to make the things we need - but will they listen? Learn more about Sarah's story at www.tumblepodcast.com, and sign up for our weekly kid-friendly podcast recommendation newsletter. Subscribe on iTunes and leave us a review. Want to ask a question on Tumble? Connect with us on Facebook, Twitter, or email and ask away. Photo credit: Microbe World