The sleepy fishing village of Minamata, Japan, 1956: and the neighbourhood cats have gone mad. They claw, scratch, and scream, sometimes breaking into convulsions before dropping dead. Then something more serious happens. Physicians are baffled by a 5-year-old girl who has trouble walking and talking. Her suite of symptoms is like nothing the medics have seen before. Two days later, the girl’s sister develops the same symptoms – and other cases quickly follow… Another unexpected discovery is that wastewater treatment plants and bioreactors seem to host bacteria with the genes for methylmercury production. Future studies of gene activation in bacterial communities as a whole may help uncover whether there is significant production of methylmercury at these facilities… Still, the ability to map methylmercury genes is a promising development on its own. The US is one of 15 countries so far to join the Minamata Convention, a UN-brokered agreement which aims to limit methylmercury worldwide – and which is named after the Japanese village where methylmercury research began… “Within that plan, monitoring will be extremely important, because how else will we know we are reaching our goals?” says Tamar Barkay of Rutgers University in New Brunswick, New Jersey.
Children in many countries are struggling to get the vitamins they need from their nutrient-poor diets. But what if bacteria could allow them to make their own? Vitamin A deficiency affects about 250 million children worldwide. Around half a million of them go blind every year, and half of those that do die within 12 months. “It’s a serious public health issue,” says Loredana Quadro at Rutgers University in New Brunswick, New Jersey… This is the first time engineered bacteria have been used to make beneficial compounds inside a living animal, says Quadro, who presented the findings at the Probiota 2015 conference in Amsterdam, the Netherlands, this week.