DES MOINES — Gov. Kim Reynolds is proposing to ratchet up the ethanol mandate in Iowa, drawing praise from the biofuels industry but concerns from others over extra cost and less consumer choice.Reynolds’ proposed House Study Bill 185, which was introduced last week, is similar in spirit to the federal biofuel mandate — which requires a certain number of gallons of renewable fuels like corn-based ethanol be blended into the nation’s fuel supply.Reynolds’ proposal goes farther by requiring almost all gasoline sold in Iowa contain at least 10 percent ethanol, with an option for the governor to raise that requirement to 15 percent in four years.