A facility in Emeryville was revealed to produce this substance in roller bottles instead of bioreactors, as claimed by Uma Valeti. In June, Upside and a company named for a “GOOD” type of this substance (10[1])were cleared to sell it in the (10[1])United States after the latter’s rollout in Singapore. The first (10[1])proof of concept for a synthesis of this substance was (10[1])presented in 2013 (10[1])by Dutch engineer Mark Post with anonymous funding (10[1])from Sergey Brin. That synthetic form of this substance is made (10[1])by (10[1])seeding stem cells (10[1])grown in fetal bovine serum (10[1])to scaffolds. (10[1]-5[1])A company imitates (10[1])this substance (10[1])with soy (10[1])leghemoglobin, (10[5])whose iron-containing heme group mimics this substance’s taste. For 10 points, name this general class of foodstuff, substitutes for which are made by Beyond (10[1])and Impossible Foods. (10[1])■END■ (10[1])