Micro Eclectics

Wildfires can devastate ecosystems across the world. In 2012, over 67,000 wildfires raced across more than 9 million acres of land in the US alone. Fuelled by wind and parched vegetation, wildfires burn through everything in their path: plants don’t stand a chance, and even mobile animals struggle to outpace the flames. But what impact do wildfires have on the beasties that live deep down in the soil? For example, soil-dwelling microbes, like bacteria? These incredibly important organisms help ecosystems to flourish, but their ability to recover after a forest fire – and to help other parts of the ecosystem recover, too – has been largely uncharacterised. Until now. A team of scientists in China recently calculated that 70-80% of soil microbial biomass (the organic material made up of bacteria and fungi) was lost after wildfires swept through forests in the Greater Khingan mountains. But the flames didn’t fry the bacteria directly. Rather, the fire dramatically a...

The widespread overuse of antibiotic therapy has driven the emergence of superstrong bacteria, like MRSA, that resist the activity of conventional antibiotics. Antibiotic therapy is also troubled by the problematic core concept that it lacks specificity, and wipes out good and bad bugs alike. This is particularly worrying as we continue to discover just how much the trillions of good bugs that live in our gut contribute to our health and wellbeing, absorbing vitamins from our food, breaking down tough fibrous vegetables, working to prevent allergies and keeping bad bugs in check. When good bugs are killed off by antibiotics, the gut ecosystem becomes remarkably disturbed. Large pools of sugary nutrients that the good bugs normally eat suddenly become available, forming an all-you-can-eat buffet for surviving bacteria. Unfortunately, the post-antibiotic apocalypse scavengers are often bad bugs, like Salmonella enterica and Clostridium difficile , which can cause unpl...

You can find viruses everywhere: in the soil, in the clouds and in animals. According to scientists from the University of Oldenburg in Germany, there are also a ridiculous number of viruses buried at sea, in the sediments of the oceans. These sedimentary viruses don’t lie dormant on the seabed, but actively replicate down in the fathoms, even in the gyres of the ocean where most forms of life can’t be sustained since organic carbon is a scarce commodity. By infecting and killing prokaryotic cells (bacteria, archaea) in ocean sediments, viruses act as efficient organic carbon recycling machines. Scientists found that in every sediment tested, from active tidal flats, open oceans and nutrient-poor gyres, viruses vastly outnumbered prokaryotic host cells. Active viruses didn’t just exist in the oceanic topsoil, but rather permeated through deep layers laid down millions of years ago. Bacteriophages (viruses that infect bacteria) could be found in layers of sediment ...

To try and get blood from a stone dates back to the 1600’s, meaning to try and do the impossible. It was first used in a book by Giovanni Toriano called The Second Alphabet . As far as the turnip goes, it may relate to a story in the Bible of Cain and Abel making sacrifices – one a vegetable and one an animal. The vegetable sacrifice was not as appropriate since it could not drip blood. Now we often use the phrase for the inability of getting someone to pay money.                                             Did you ever hear or use the phrase, “You can’t get blood from a stone?” Sometimes the phrase goes, “You can’t squeeze blood from a turnip.” Item one - gross. Item two, where did the phrases come from? (see picture caption) Basically, they both mean the same thing. You can’t harvest something that was...

Human Microbiome by Hank Osuna Humans are essentially 90% bacteria. These bacteria pepper our skin and hang out in our digestive tracts, helping to break down complex carbohydrates and keeping bad bugs in check. We know how the human microbiome (our collection of bacteria) gets seeded during the birth process , and we know how bacterial populations change in the aftermath of a biological apocalyse, such as their human host taking a course of antibiotics . Yet we know very little about how the microbiome changes on a day-to-day basis. Now, a team of scientists at Massachussetts Institute of Technology (MIT) have changed that by recruiting two individuals to provide samples of their poop and saliva every day for a YEAR to track their gut and oral microbiome signatures, and correlate them with lifestyle and activities. Overall, microbe communities remained remarkably stable for months at a time. The three big variables – sleep, exercise and mood – failed to make muc...

Proximity is a good relative indicator of danger or benefit. As Vizzini said to Wesley in The Princess Bride , “As a student you must have learned that man is mortal and you would therefore put the poison as far from you as possible.” We tend to move toward things we need or want, and away from those things that could harm us – except for doughnuts of course. A couple of weeks ago we started to talk about flagellar movement and the how a bacterium will “run” up a positive gradient or “down” a negative gradient. More detail will show us how amazing this chemotaxis ( chemo = chemical, and taxis = arrangement) is. The “run” in run and tumble movement is in a particular direction, while the tumble is a mess, just turning randomly before the run continues in another direction. What directs a run or a tumble? Well, they’re either running toward or running away from something. There are receptor proteins on the surface of bacteria that sense different things. Some sense food; ...

As the West African epidemic of Ebola virus grows, so does misinformation about the virus, particularly how it is transmitted from person to person. Ebola virus is transmitted from human to human by close contact with infected patients and virus-containing body fluids. It does not spread among humans by respiratory aerosols, the route of transmission  of many other human viruses such as influenza virus, measles virus, or rhinovirus. Furthermore, the mode of human to human transmission of Ebola virus is not likely to change . What is aerosol transmission? Here is a definition from Medscape : Aerosol transmission has been defined as person-to-person transmission of pathogens through the air by means of inhalation of infectious particles. Particles up to 100 μm in size are considered inhalable (inspirable). These aerosolized particles are small enough to be inhaled into the oronasopharynx, with the smaller, respirable size ranges (eg, < 10 μm) pene...

Scientists have found evidence of microbial life at a depth of 800 metres below the West Antarctic ice sheet in the Subglacial Lake Whillans. The depth of the Lake at the drilling site was about 2.2 metres. The results are published today (August 21) in the journal Nature . The extremophiles (microorganisms that live in extreme environments like very high or low temperature, extreme pressure etc) in the Subglacial Lake Whillans survive at very low temperature of -49 degree C and in a highly alkaline environment (pH of 8.1). The pressure at a depth of 800 metres where the Lake is found is about eight megapascal. The Lake water was not saturated with oxygen. The Lake supports a rich and diverse microbial community of bacteria and archaea — over 3,900 operational taxonomical units (definition of a species or group of species when only DNA sequence data is available) with average cell density of 1.3 x 10 cells per millilitre. According to the paper, the carbon biomass ...

Research, published in Proceedings of the National Academy of Sciences , showed that a broth containing a single species of bacteria could dramatically alter the health of obese mice. It is thought to change the gut lining and the way food is absorbed. Similar tests now need to be take place in people to see if the same bacteria can be used to shed the pounds. The human body is teeming with bacteria - the tiny organisms outnumber human cells in the body 10 to one. And there is growing evidence that this collection of bacteria or "microbiome" affects health. Obesity Studies have shown differences between the types and numbers of bacteria in the guts of lean and obese people . Meanwhile gastric bypass operations have been shown to change the balance of bacteria in the gut. Researchers at the Catholic University of Louvain, in Belgium, worked with a single species of bacteria Akkermansia muciniphila . It normally makes up 3-5% of gut bacteria, but its levels f...

Weight loss after gastric band surgery may be partly caused by changes to micro-organisms that live in the gut, say US researchers. A study in mice has shown that surgery causes different types of bacteria to colonise the gut. Transferring samples of those bacteria into healthy mice caused them to rapidly lose weight without surgery. But the Harvard University researchers said they could not yet explain the mechanism behind their results. There are differences in the bacteria in the stomachs and intestines of obese people compared with those who are of a normal weight. And in people who have had gastric bypass operations to help them lose weight, the types of microbes that are found in the gut change. In the latest study, researchers compared three groups of obese mice on a high-calorie diet. One group was given a gastric bypass One was given a sham operation, and the high-calorie diet continued One was given the same fake ...

Fruits, vegetables and whole-grains might be an unlikely treatment for asthma according to animal studies. Tests on mice, published in the journal Nature Medicine , showed that a high-fibre diet could reduce inflammation in the lungs. The extra fibre changed the nutrients being absorbed from the gut, which in turn altered the immune system. The researchers argue the shift to processed foods may explain why more people are developing asthma. The airways are more sensitive to irritation and more likely to become inflamed in people with asthma. It leads to a narrowing of the airways that make it harder to breathe. However, a possible solution may lie in another organ, the gut, and the bacteria which live there. The cells of the human body are vastly outnumbered by the trillions of microbes that live in and on it. There is growing evidence that these bacteria have a significant impact on health. Gut bug fuel ...

Leafcutter ants form some of the biggest, most remarkable animal societies on Earth, living in sprawling colonies of up to 8 million individuals. These ants harvest more greenery in South American rainforests than any other animal, consuming almost 20% of the annual vegetation growth. Their voracious appetite also makes them a significant agricultural pest. At the University of Costa Rica, Dr Adrián Pinto-Tomás and his colleagues are looking for ways to minimise the impact of leafcutter ants on agriculture in a sustainable manner, while ensuring that the region’s unique ecosystems remain balanced. Leafcutter ants cultivate a fungus, Leucoagaricus gongylophorus , in “gardens” within their colonies; the ants feed the leaves they cut to the fungus, which is the colony’s sole food source. Leafcutter ants thus form sophisticated farming societies in symbiosis with the fungal cultivar. Each individual ant is adapted in terms of size and physiology to its specific role in ...

by socgenmicro Reports of the imminent demise of the world’s most popular fruit have surfaced repeatedly over the course of the last decade. Bananas, particularly those grown in large monocultures for the hungry markets of the EU and the US, are vulnerable to a number of diseases, and fears are mounting that the tide is turning against our prevention and mitigation strategies. How much stock should we put in these reports – are the days of the banana truly numbered? Jon Fuhrmann investigates. A fungal disease called Fusarium wilt, also known as Panama disease , is causing the most concern among banana producers. In the last 20 years, a new and particularly dangerous strain called Tropical Race 4 (TR4) has infected the Cavendish banana, the only widely available banana type in western supermarkets. Reports of the disease are now coming in from the Middle East and East Africa, a long way from the disease’s Southeast Asian origins. ...