Bacterial α-Amylase in GM Rice

α-Amylase is an enzyme widely used in feed, food processing and ethanol production. During ethanol production, starch is liquefied by amylase before it is fermented by yeasts to produce ethanol. Currently, the enzyme is being extracted from amylase-producing bacteria. Although recent developments in extracting amylase from bacteria lower production costs, cost-efficient method of deriving amylase is desirable for the rapidly-expanding ethanol industry. Previous studies in using transgenic crops as bioreactors demonstrated a more economical way of producing industrial enzymes. The use of starchy crops like rice and corn in producing α-amylase presents more advantages over previously reported α-amylase-producing GM tobacco, alfalfa and beans since the enzyme does not need to be extracted or purified, and is ready for various applications.

By inserting a bacterial gene coding for α-amylase, a group of Chinese scientists obtained rice varieties with α –amylase activity reaching about 15,000 units per gram of seed (one unit is defined as the amount of enzyme that produces 1 μmol of reducing sugar in 1 min at 70°C). Compared to α –amylase extracted from microorganisms, the enzyme obtained from GM rice was found to be stable for a longer time since it is contained in seeds. It was also found to be stable even at high temperatures. Further studies are being made to characterize the α –amylase expressing GM rice.

Read the abstract at http://www.springerlink.com/content/d45276vg37368533/?p=daffb54c619b4218b74e40e92226ea52&pi=0 or the full paper at http://www.springerlink.com/content/d45276vg37368533/fulltext.pdf