Natural Sweeteners? Probably Not Erythritol...

I came across a post about fructose in Vitamin Water that also had some interesting facts about erythritol, which is sometimes sold as a "natural" sweetener. Here are quotes from patents and scientific papers:

The present method of producing erythritol by fed-batch and repeated fermentation of sugars by microorganisms which produce erythritol.
By fed-batch fermentation is meant a fermentation in which microorganisms are fed by the successive addition of substrates, and in which the product and the co-products of the fermentation remain in the medium until the end of fermentation.
By sugars is meant in the present invention all the carbonaceous sources which may be directly assimilated by the microorganisms which produce erythritol. Such sugars are chosen for example from the group consisting of glucose, saccharose, fructose, maltose, xylulose and maltulose, on their own or in a mixture. By extension, sugars also means certain sugar alcohols (or polyols) such as mannitol or sorbitol which, being assimilated by said microorganisms, will also lead to the production of erythritol.

As the writer at the Golden Spiral says, "I’m sorry… does that sound natural?"