According to Forbes, the new Amryis's Purecane product is produced is by fermenting sugarcane,
But the Amyris scientists developed a unique method of making Reb-M using fermentation, the basic process we use to make beer, wine, and bread. By using a yeast culture to ferment sustainably-sourced sugarcane, Amyris was able to make very pure, sustainable Reb-M.
Their FAQ repeats this claim and says that the product contains no GMOs,
No. PURECANE™ Brand Sweetener (fermented sugarcane Reb M) is naturally derived from sugarcane grown in Brazil. Using the age-old process of fermentation, we remove the yeast as part of our purification process that enables us to create PURECANE™ Brand Sweetener (fermented sugarcane Reb M). We have received NSF Non-GMO certification on our PURECANE™ No Calorie Sweet Packets.
Their website even claims the product is "all natural" and "NON GMO"
That’s what we said when we discovered a revolutionary way to make sugarcane into an all-natural, zero calorie sweetener.
Is there any outside verification that Reb-M even be made through fermentation of sugarcane? We take a product everyone loves (sugar), ferment it (a 7000 year old natural process) and we get a supremely valuable 0-calorie sweatener only found in trace quantities inside of the "super-sweet steviol glucosides in the stevia plant"? Is there any evidence this claim is true?
