Business Green: A British company that uses a genetically modified compost-heap bug to produce biofuel from rubbish has signed a $500m (£319m) contract with a US firm. TMO Renewables developed a strain of “turbo-charged” bacteria that can turn tea bags, cardboard, wood and other household waste into fuel for cars and trucks. The Guildford-based company signed a 20-year, $25m-a-year deal with US firm Fiberight. The technology is part of a wave of “second generation” biofuels that are not made …