see this:
http://www.truthinlabeling.org/organicP.html (explains that it has naturally occurring MSG in it, or something close - not a glowing article)
and this:
http://articles.findarticles.com/p/a...71/ai_82847389 actually explains what it is and how it's used and how it's made (it's generally used as a flavor enhancer)
The most relevant part of the second link:
"Autolysis involves self-digestion of the yeast cells where the yeasts' own enzymes break down the cells under carefully controlled conditions. "Autolysates" comprise the entire contents that result from this process. Yeast extract is the soluble portion of the autolysate after cencrifugation and removal of the insoluble cell wall. The ingredients are concentrated into a paste and, subsequently, can be dried. These ingredients are labeled as "autolyzed yeast extract" (USDA) or "yeast extract" (FDA). If the cell wall is not removed the product is "autolyzed yeast".
Through the processing of autolyzed yeast and yeast extract, water-soluble flavor-enhancing compounds such as peptides, amino acids (including glutamic acid), monosaccharides, nucleotides and salts, are released. Some specialty yeast extracts contain higher levels of nucleotides. Through drying processes, yeast extracts can take on enhanced flavor characters of their own such as meaty and roasted notes.
"With autolyzed yeast, you've broken the cell wall, but all the components are still there, nothing is removed, including the cell wall," says Hildabrand. "This makes for a turbid product that is useful where clarity is not important, as in stews and certain soups. With the cell wall removed, yeast extracts are clear so they can be used in applications such as clear bouillon."
~amey
__________________
Mama to Daniel, 8 and Nicholas, 5 years old!
One of my most favorite places on Earth. Lake's Pond, Fort Ann, NY.
sorry, couldn't resist! 
Linear Mode
