Biotechnology was first applied in medicine, then farming. Today, dozens of lifesaving drugs are on the market, while many crops are genetically engineered to withstand weed killers. Now, a 2-year-old push to develop alternative fuels is driving biotechnology’s growth into the industrial sector. Thousands of corporate executives and scientists gather this weekend in Orlando, Fla. for an industry trade show specifically aimed at touting biotechnology’s so-called third wave, industrial applications. The word on everyone’s lips: ethanol.