Fermentation process saccharides

The fermenting liquor finally obtained in the above fermentation contains lactic acid together with various impurities such as un-reacted raw materials, cells and culture media-derived saccharides, amino acids, carbojq lic acids, proteins and inorganic salts. Therefore, the isolation and purification steps are needed for obtaining a highly pure product needed in the polymer s synthesis. In the usual fermentation process, the generated lactic acid is neutralized in situ with calcium oxide or ammonia. When calcium oxide is used for the neutralization, calcium lactate is precipitated out. 

Com symps [8029-434] (glucose symp, starch symp) are concentrated solutions of partially hydrolyzed starch containing dextrose, maltose, and higher molecular weight saccharides. In the United States, com symps are produced from com starch by acid and enzyme processes. Other starch sources such as wheat, rice, potato, and tapioca are used elsewhere depending on availability. Symps are generally sold in the form of viscous liquid products and vary in physical properties, eg, viscosity, humectancy, hygroscopicity, sweetness, and fermentability. 

While these results are promising, the productivity of these modified organisms are still far below the levels of productivity for saccharide fermentation bacteria (>100 g/L-h). However, when compared in terms of productivity per hectare, these direct C02-to-alcohol conversion processes are competitive with biodiesel from algal lipids and even superior to land-crop-based ethanol (Sheehan 2009). 

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