Sugar genetic engineering

Progress in fermentation technology has made it possible to raise the accumulation and the yield of L-glutamic acid above 100 g/L and 60% based on the total amount of sugar. AppHcation of genetic engineering techniques for further improvement is also in progress. 

Genetically engineered plants are special invaders. Modified crops of nutritional interest are believed to be more invasive that their natural counterparts (Wolfenbarger 2000), although these views have been challenged for oilseed rape, potato, maize, and sugar beet (Crawley 2001). 

As discussed earlier in this chapter, enzymes are the basis for yeast conversion of hexose (six-carbon) sugars, such as glucose and mannose, to ethanol. These enzymes also could be genetically engineered to improve the efficiency of alcohol production several biotechnology firms are exploring this possibility. 

Forest Products Laboratory have discovered a xylose-fermenting yeast (Candida tropicalis). Thus it now is possible to convert all wood sugars to ethyl alcohol with a combination of yeasts. Isolation of the specific enzymes and genetic engineering of the enzymes could dramatically improve the efficiency of this conversion. 

To be cost effective, the process must use organisms capable of fermenting the full spectrum of five- and six-carbon sugars released from cellulose and hemicellulose. The advent of efficient genetically engineered organisms equipped with metabolic pathways to handle both types of sugars is an important... 

In the United States, herbicide-tolerant genetically engineered sugar beet was approved in 1998, and has been available to the market since 1999. However, farmers have been wary... 

---