Posts tagged: dirt

Micro links: dirt is alive, light is a killer, and you’re breathing plant viruses

Ultraviolet light kills microbes – specifically UVC rays. Not surprising if you’ve ever laid a stinky blanket outside (or, you know, your roller derby kneepads). A new study tested UVC light on skin wounds in mice, and found that it kills germs without damaging skin cells or slowing healing. (Unanswered question: what about the good skin microbiota?) The researchers are excited about this as an alternative to antibiotics, since it’s hard to evolve resistance to radiation.

D. radiodurans - pic from Wikipedia(Well, D. radiodurans has done it, but they say they can kill that off too, if they just crank up the voltage enough. That’s D. radiodurans in the picture – it lives in a tetrad so it has four copies of DNA segmented from each other. Its DNA is packed into toroids to limit damage, and it can use the four copies to fix each other. Pretty awesome bug, famously nicknamed “Conan the Bacterium.”)

Lab tests on pesticides have been missing something big: soil microbes. A recent study on RoundUp ready weeds (that is, they are resistant to the pesticide glyphosate, which is supposed to kill weeds but leave transgenic soybeans alone) found that the plants survive better in sterile lab soil than in “field soil” with its microbes intact. One possibility: the plants are weakened by glyphosate, and pathogenic microbes take advantage.

Quote of the day, from one of that study’s authors: “Dirt is a living organism”

You’ve heard of airborne infections. Try not to think about how many germs are a single breath of air – too late, I guess. It’s like when you see sunlight streaming through a window, illuminating all the dust in its path, and realize you’re breathing that stuff in all the time. Well, scientists in Korea have done the first metagenomic analysis of the “air virome” – all the viruses that are floating around. (It turns out the most common type is plant viruses.) Maybe the air is a living organism too?

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