By Emily Waltz
Seed and chemical giant Bayer in September announced a $100-million joint venture with synthetic biology firm Ginkgo Bioworks, with the lofty goal of engineering nitrogen fixing microbes and reducing global fertilizer use by one-third. In the same month, Indigo Ag, a microbe-focused startup, announced it had raised $156 million, in a big bet on plant microbes to replace fertilizers and pesticides and improve crop yields.