Aspartame was first created in 1965 and it was discovered by mistake.
The embedded patent above is the patent issued to Searle in 1970 for what would be known as aspartame. It is created through a fermentation and synthesis process. *Please note that GMO bacteria was not a part of the patent I have embedded above.*
The sugarlike taste of aspartame was discovered accidentally by James Schlatter, an American drug researcher at G.D. Searle and Co. in 1965. While working on an antiulcer drug, he inadvertently spilled some APM on his hand. Figuring that the material was not toxic, he went about his work without washing it off. He discovered APM's sweet taste when he licked his finger to pick up a piece of weighing paper.
However, as of 1999, genetically modified bacteria (GMO-bacteria) was being used in the process.
Although its components aspartic acid, phenylalanine, and methanolccur naturally in foods, aspartame itself does not and must be manufactured. NutraSweet' (aspartame) is made through fermentation and synthesis processes.
I have heard some claim that the aspartame comes from the "feces" of GMO bacteria, but I have not been able to confirm that this fermentation process produces feces or the equivalent thereof.
...an investigation by the Independent on Sunday revealed that Monsanto, the pioneering GM food giant which makes aspartame, often uses genetically engineered bacteria to produce the sweetener at its US production plants.
Source: eNotes; The Independent