Carbohydrate fermentation maltose

The carbohydrates in the hydrolysates and fermentation media xylose, arabinose, fructose, glucose, mannose, galactose, maltose, maltotriose, and sucrose are analyzed by gas chromatography. The liquid samples are derivatized with Trimethylchlorosilane solution (Pierce Biotechnology, Inc., Rockford, IL) for detection. The GC was a Shimadzu GC-17A (Kyoto, Japan) with an injection volume of 1 pL and a temperature of 340 C. The column is a Phenomenex ZB-5 (Torrance, CA) and the detector is a flame ionization detector (FID) set at 340°C. The column carrier gas is helium with a flowrate of 1.1 mL/minute. 

The principal pathway for the fermentation of glucose and fructose is the Embden-Meyerhof-Parnas route (alternatively named EMP or glycolytic sequence). Wort sucrose is hydrolysed extracellularly and maltose and maltotriose intracellularly. Intracellular storage carbohydrates such as glycogen and trehalose may also serve as sources of intracellular monosaccharide. 

The Crabtree effect does not operate in all species of the genus Saccharo-myces and is absent in Hansenula sp. and Candida sp. (Table 17.5). The effect is expressed in the presence of fructose as well as glucose but is less marked when maltose, mannose or galactose is the fermentable carbohydrate (Table 17.6). 

PLA is an aliphatic polyester, derived from renewable resources, e. g. com starch or sugarcane sucrose. It is a pol)nner produced from lactic add (Figure 2), which is obtained from the fermentation of various carbohydrate spedes glucose, maltose and dextrose from corn or potato starch sucrose from beet or sugar cane and ladose from cheese whey [63]. 

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