Micro Eclectics

When you think of iron, you probably think of anvils and suits made by Tony Stark - iron is ore that comes from a mine. Now imagine that half of the iron in that object owes its existence to bacteria living two and a half billion years ago.  Clark Johnson, a professor of geoscience at the University of Wisconsin-Madison, and former postdoctoral researcher Weiqiang Li examined samples from the banded iron formation in Western Australia. Banded iron is the iron-rich rock found in ore deposits worldwide, from the proposed iron mine in Northern Wisconsin to the enormous mines of Western Australia. These ancient deposits, up to 150 meters deep, were begging for explanation.  Scientists thought the iron had entered the ocean from hot, mineral-rich water released at mid-ocean vents that then precipitated to the ocean floor. Now Johnson and Li, who is currently at Nanjing University in China, show that half of the iron in banded iron was metabolized by ancient bacteria living al...

One Shake Shack French fry may lead you to eat a whole batch, and don't even get started on the power of Doritos. According to a new study using rats, that high-fat indulgence literally changes the populations of bacteria residing inside the gut and also alters the signaling to the brain. The result? The brain no longer senses signals for fullness, which can cause overeating--a leading cause of obesity.  The findings presented this week at the Annual Meeting of the Society for the Study of Ingestive Behavior liken a high fat diet to how a sudden significant shift in temperature might impact the people who live in the affected area: Some people will be fine. Others will become ill. "When we switch the rats to a high fat diet, it reorganizes brain circuits," explained Krzysztof Czaja, DVM, PhD, a principal investigator on the study who is an associate professor of neuroanatomy at the University of Georgia College of Veterinary Medicine. "The brain is changed by e...

Television commercials assure us that probiotic products are good for our health, with claims ranging from improved digestion to managing allergies and colds, If so, why wouldn't plants also benefit from certain microbes? In plants, beneficial bacteria and fungi are endophytes. Scientists have known for decades that plants like legumes (peas, beans, and lentils) have beneficial bacteria in nodules attached to their roots. These bacteria "fix" vital nitrogen, turning it into a form the plant can easily use. However, researchers have recently found some nitrogen-fixing bacteria actually live inside plant tissue--in the leaves, stems, and roots--with impressive results. Sharon Doty, an associate professor at the University of Washington, was one of the first to discover these bacteria, and their successful transfer between plants. A comparison of rice plants grown without the endophyte (E-) and with the endophyte (E+). Photo by Hyungmin Doty and her team isolated e...