from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun A white crystalline sugar, C5H10O5, that is a component of most hemicelluloses in plants.
from The Century Dictionary.
- noun A colorless, dextrorotatory carbohydrate, , prepared by the action of dilute sulphuric acid on wood-gum or corncobs. It reduces alkaline copper solutions, crystallizes in needles or orthorhombic prisms, and melts at 144–145° C. Also called
from the GNU version of the Collaborative International Dictionary of English.
- noun (Chem.) An unfermentable sugar of the pentose class, C5H10O5, formed by the hydrolysis of xylan; wood sugar.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun chemistry One of the
pentoses, C5H10O5, a white crystallinesubstance, a sugar, derivedfrom wood.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun a sugar extracted from wood or straw; used in foods for diabetics
Sorry, no etymologies found.
Xylitol: A sugar alcohol, derived from xylan a complex sugar chain, sort of like cellulose, which is found in corncobs, straw, almond shells, and birch bark which is then broken down into individual units of a simple sugar, called xylose, which is then hydrogenated to make xylitol.
S. cerevisiae strains to convert five-carbon sugars such as xylose into ethanol.
The product is manipulated, using a process that includes alpha-amylase, oligosaccharides, and xylose isomerase, into a syrup that is anywhere from 90% fructose/10% glucose to 42% fructose/58% glucose.
What, on earth, compelled anyone to use xylose isomerase and oligosaccharides in the first place?
The latest cellulose ethanol processes use recently identified enzymes to break down the biomass to separate the cellulose, hemicellulose and lignin cheaply, and new genetically modified yeasts which can ferment the C5 xylose sugar from hemicellulose as well as, and at the same time as, the normal C6 fermentation from cellulose.
Thus a-xylose were the substrates for the 2R-aldose enzymes in their production of fructose
Step 2: Enzymes A mix of cellulase enzymes is then added to convert the cellulose and hemicellulose molecules into the simple sugars glucose and xylose.
Then there are two complicated steps: first, introducing enzymes, called cellulases, to break the cellulose down into glucose and xylose; and second, using yeast and other microorganisms to ferment those sugars into ethanol.
As I said in my original post, it is based on new genetically modified yeasts capable of converting xylose sugar to ethanol alongside the traditional glucose fermentation.
Xylans are polymers of xylose and are constituents of plant cell walls.