At this point, there is not really a battle of food vs fuel. Corn yield has increased so much that the net corn yield after ethanol production has increased dramatically. Moreover, only the starch portion of the corn kernel is converted to sugar and then to ethanol. The rest is used to make high-protein feed supplements, which are actually more nutritious than ground corn. We could actually develop biotechnology to make petroleum, by the way. An organism has been discovered which actually makes petroleum. It was found near oil wells and was able to make petroleum in a laboratory setting. The problem is that the natural organism did so very slowly. But microbiologists are very good at modifying organisms to make them do what they do much faster. But they need funding for that, and no one seems to want to fund such research.