An enzyme found naturally in certain soil bacteria, which helps those bacteria to utilize soilbome nitrogen. When its gene (GDH gene) is inserted into com plant via genetic engineering, the resultant plant production of glutamate dehydrogenase enables that com plant to better utilize soilbome nitrogen. As a result, that genetically engineered corn (Zea mays L.) has protein yield increase of approximately seven percent, according to research begun in 1981 by David Lightfoot.