Expression of a bacterial alpha-amylase gene in transgenic rice seeds.
An alpha-amylase gene from Bacillus stearothermophilus under the control of the promoter of a major rice-seed storage protein was introduced into rice. The transgenic line with the highest alpha-amylase activity reached about 15,000 U/g of seeds (one unit is defined as the amount of enzyme that produces 1 mumol of reducing sugar in 1 min at 70 degrees C). The enzyme produced in the seeds had an optimum pH of 5.0-5.5 and optimum temperature of 60-70 degrees C. Without extraction or purification, the power of transgenic rice seeds was able to liquify 100 times its weight of corn powder in 2 h. Thus, the transgenic rice could be used for industrial starch liquefaction.
Xu
Xiaoli
X
Institute of Insect Sciences and National Key Laboratory of Rice Biology, School of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.
Fang
Jun
J
Wang
Wei
W
Guo
Jianli
J
Chen
Pinnan
P
Cheng
Jiaan
J
Shen
Zhicheng
Z
D015139:Blotting, Southern; D001411:Geobacillus stearothermophilus / Q000201:enzymology* / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D012275:Oryza / Q000201:enzymology* / Q000235:genetics; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids; D013213:Starch / Q000378:metabolism; D013696:Temperature; D014170:Transformation, Genetic; D000516:alpha-Amylases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*
D013213:Starch; D000516:alpha-Amylases