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Microbiology

From predator to plant in one gulp

The story of a predator that, upon eating a certain food, suddenly becomes a peaceful plant. Sort of. Free-living versus symbiotic A working definition for symbiosis is two or more species that live and interact. Mutualism means that each derives a certain benefit from the other, or at most causing no harm to each other. […]

Yeah, yeah, the flu virus

Since the Swine Influenza Media and Blogging Pandemic has died for now, I think I can finally write about ‘flu myself.  A quick aside: until I was about 15, I thought that the word Influenza came from the Arabic “Inf-Il-enza” meaning “goat’s nose”, which it is a bit runny, like a dog’s, or like someone […]

Blood, sweat and spit

A short follow up to the previous post on latherin. A quick reminder: latherin is a protein that exists in the horse’s sweat and saliva. In the sweat, latherin acts like a detergent, wetting the horse’s coat to allow for better water evaporation and hence better cooling. In the saliva, it helps wet the horse’s […]

Skin Flick 2: Statistic Boogaloo

Reports on the first metagenomic survey of skin bacteria (see my previous post) did not go unnoticed by the popular media. Reports appear in US News & world Report, LA Times, Times of India, National Geographic, and Scientific American. All these articles have one thing in common: they are wrong. Yes, even Scientific American. All […]

Skin flick

Interesting report in Science today about the human skin metagenome. The skin is a fairly large organ, and it is home to an estimated 1012 bacteria. It is the first barrier our body poses against pathogens, toxins, and sarcastic comments.  An adult’s skin area is about 2m2, virtually all of it exposed to the outside […]

Light for Cellular Communication?

Don’t you know We’re all light Yeah, I read that someplace –XTC This is interesting: an article in PLoS ONE that claims that Paramecia can communicate using light. The author, Daniel Fels from the Swiss Tropical Institute in Basel, separated two Paramecia populations using quartz or glass vials, grew them in the dark, and checked […]

Size matters. Life is Live.

1976: Prologue In July 27, 1976, the American Legion, a US military veterans association, held a large meeting at the Bellevue Stratford Hotel a hotel in Philadelphia PA, celebrating the USA’s bicentennial year. Within 2 days, guests  started falling ill with an atypical pneumonia. By the end of the week, 221 people were ill and […]

Children’s science books: Bacteria Galore by Sunday at Four

Jonathan Eisen started something nice in his blog: a review of children’s science books. So I think I’ll follow suit, especially since my first review will combine two of Jonathan’s  faves:  Microbiology and Open Access.  The book is “Bacteria Galore by Sunday at Four” by Mel Rosenberg, a Professor of Microbiology at  Tel-Aviv University who […]

Ribosomal paleontology

In the latter epoch of those  2 billion-odd years between non-life and life on early Earth, our ancestral molecular replicators were quite probably RNA, not DNA. There are many arguments for this RNA world hypothesis: RNA can store information in its sequence, and self -duplicate; it can also catalyze reactions as a ribozyme. So technically, […]

Baby it’s cold outside

Most of the Earth’s surface is colder than the inside of your refrigerator. Deep sea temperatures are almost universally 2-4C. That’s already 73%  of the Earth’s surface. Then add to that the  polar regions, mountain ranges and permafrost and you have about 85% of the Earth’s surface constantly at refrigerator or freezer temperatures. While there […]

Searching for Life on Earth

But if you know what life is worth, You will look for yours on Earth — Bob Marley – “Is there life on Earth?” – “Well, duh.” – “I mean, is there another kind of life on Earth?” – “WTF?” – “You know… there could be these bugs that, like, they’re all around us and […]

Metagenomes as a diagnostic tool?

Can we learn about an environment by looking at the bacteria living in it? Can we sequence a metagenome, and then say: ”according to the active genes in this water sample it appears to be too rich in metal ions / sewage products / other pollutants” ? In the foreseeable future could we sequence a […]

Every Man an Island, Pt. 2

(Continued from  part 1) Why we are islands In the previous post we have seen how  our bacterial population affects  our weight  and that by changing our dietary habits we can change the species composition in our guts. Also, we saw how a metagenomic analysis can lead to verifiable hypotheses: using a metagenomic analysis, Gordon’s […]

Every Man an Island, Pt. 1

No man is an island, entire of itself — John Donne, Meditation XVII Scanning electron microscope images of B. thetaiotaomicron, a prominent human gut bacterium, and the intestine. From: Human Gut Hosts a Dynamically Evolving Microbial Ecosystem Gross L PLoS Biology Vol. 5, No. 7, e199 doi:10.1371/journal.pbio.0050199 Only one out of ten cells in our […]