There’s no peak in sight – fitness peak, that is – for the bacteria in Richard Lenski’s Michigan State University lab.
Lenski, MSU Hannah Distinguished Professor of Microbiology and Molecular Genetics, has been running his evolutionary bacteria experiment for 25 years, generating more than 58,000 generations. In a paper published in the current issue of Science, Michael Wiser, lead author and MSU zoology graduate student in Lenski’s lab, compares it to hiking. (more…)
In the perpetual darkness of a limestone cave, UA researchers have discovered a surprisingly diverse ecosystem of microbes eking out a living from not much more than drip water, rock and air. The discovery not only expands our understanding of how microbes manage to colonize every niche on the planet but also could lead to applications ranging from environmental cleanup solutions to drug development.
Hidden underneath the hilly grasslands studded with ocotillos and mesquite trees in southeastern Arizona lies a world shrouded in perpetual darkness: Kartchner Caverns, a limestone cave system renowned for its untouched cave formations, sculpted over millennia by groundwater dissolving the bedrock and carving out underground rooms, and passages that attract tourists from all over the world. (more…)
MU scientists say discovery could save farmers billions and protect the environment.
COLUMBIA, Mo. — Nitrogen fertilizer costs U.S. farmers approximately $8 billion each year, and excess fertilizer can find its way into rivers and streams, damaging the delicate water systems. Now, a discovery by a team of University of Missouri researchers could be the first step toward helping crops use less nitrogen, benefitting both farmers’ bottom lines and the environment. The journal Science published the research this month.
Gary Stacey, an investigator in the MU Bond Life Sciences Center and professor of plant sciences in the College of Agriculture, Food and Natural Resources, found that crops, such as corn, are “confused” when confronted with an invasive, but beneficial, bacteria known as rhizobia bacteria. When the bacteria interact correctly with a crop, the bacteria receive some food from the plant and, simultaneously, produce nitrogen that most plants need. In his study, Stacey found that many other crops recognize the bacteria, but do not attempt to interact closely with them. (more…)
ANN ARBOR — University of Michigan researchers and their University of Hawaii colleagues say they’ve solved the longstanding mystery of how mercury gets into open-ocean fish, and their findings suggest that levels of the toxin in Pacific Ocean fish will likely rise in coming decades.
Using isotopic measurement techniques developed at U-M, the researchers determined that up to 80 percent of the toxic form of mercury, called methylmercury, found in the tissues of deep-feeding North Pacific Ocean fish is produced deep in the ocean, most likely by bacteria clinging to sinking bits of organic matter. (more…)
Under the microscope, they look like they could be from another planet, but these microscopic organisms inhabit the depths of our oceans in nearly infinite numbers.
To begin to identify where, when, and how much oceanic plankton can be found around the globe, a group of international researchers have compiled the first ever global atlas cataloguing marine plankton ranging in size from bacteria to jellyfish. The atlas was published on July 19, 2013, in a special issue of the journal Earth System Science Data. (more…)
Berkeley Lab scientists image cell-to-cell connections between soil microbes
The next time your Facebook stream is filled with cat videos, think about Myxococcus xanthus.The single-cell soil bacterium also uses a social network. But forget silly distractions. M. xanthus relies on its connections to avoid getting eaten and to score its next meal.
That’s the latest insight from a team of Berkeley Lab scientists. Using several imaging techniques, they saw for the first time that M. xanthus cells are connected by a network of chain-like membranes. (more…)
Environmental conditions have a much stronger influence on the mix of microbes living in various parts of your body than does competition between species. Instead of excluding each other, microbes that fiercely compete for similar resources are more likely to cohabit in the same individual.
This phenomenon was discovered in a recent study of the human microbiome – the vast collection of our resident bacteria, fungi, and other tiny organisms. (more…)
In a twist on “survival of the fittest,” researchers have discovered that evolution is driven not by a single beneficial mutation but rather by a group of mutations, including ones called “genetic hitchhikers” that are simply along for the ride. These hitchhikers are mutations that do not appear to have a role in contributing to an organism’s fitness and therefore its evolution, yet may play an important role down the road.
Researchers from Princeton University found in a study of 1,000 generations of adaptation in 40 yeast populations that about five to seven specific mutations, rather than just a one, are needed for an organism to succeed. The knowledge of how mutations drive evolution can inform our understanding of how tumors resist chemotherapeutics and how bacteria evolve resistance to antibiotics. The study was published July 21 in the journal Nature. (more…)
