Showing posts with label bacteria. Show all posts
Showing posts with label bacteria. Show all posts

Monday, February 18, 2013

Carl Woese

Somehow I missed this but Carl Woese passed away at the end of 2012. Past students will recall his name as the person who discovered that within the prokaryotes there are two major groups of life that are as different from each other as either of them are to the eukaryotes: the Bacteria and the Archaea. I've always loved his story - the scientist who sees something incredible that noone has ever seen, has to fight to get people to believe him, then moves from outcast to hero when the scientific world finally accepts his work.  Woese was bestowed the National Medal of Science - probably the highest scientific award in the US -  in 2000.

(image from news.illinois.edu)


http://www.nytimes.com/2013/01/01/science/carl-woese-dies-discovered-lifes-third-domain.html?_r=0



Wednesday, February 13, 2013

Bacteria in the atmosphere - another extreme environment?

A group out of Denmark recently did biochemical and bacteriological analysis of hailstones. A quick glance at some neat things in here: 

  • bacteria found at a density of ~2000 cells/ml. That's not very high compared to soil at ~10,000,000 cells/g, but hey, this is in a hailstone! 
  • Single cloud droplets however are not individually very poluation. The researchers estimate that 1 in 1,000,000 storm cloud droplets have a a bacterial cell in them. 
  • this paper also touches on the carbon sources and how that may relate to the bacteria

Realize that there are a lot of bacteria hanging out in the atmosphere. There's been a lot of work on this recently, and some of it suggests that these bacteria are metabolically active while up there. There is also research that suggests that these bacteria can act as nucleation points for condensation. I like another statement that is made in this paper that considers the atmosphere as yet another one of our "extreme environments"  - another model for life on other planets perhaps? 


Ĺ antl-Temkiv et al. 2013 Hailstones: A Window into the Microbial and Chemical Inventory of a Storm Cloud. PLOS 



http://www.plosone.org/article/info:doi/10.1371/journal.pone.0053550



Monday, February 11, 2013

Life in subglacial Antarctic lake

Over the past year or so a number of research teams have been drilling deep into glacial ice to get at pockets of water deep below that have been in theory isolated for a very long time from the outside environment. They want to see what exactly can live in those conditions and see if these are some new life forms that we just haven't seen before. What is this environment like? Well, no sunlight penetrating down there, so no light energy driving energy production down there. Very cold too, and the pressure must be reasonably high.

One of the challenges that comes with these studies is that they have to drill a long ways down, and they have to be able to support that any life they find was from the water pocket and not contamination from above carried down by the drill.

There is a nice New York Times article about this that can be found at this link (Feb 6, 2012, Science section). They also have a great photo that shows the first view into one particular lake that I have linked into here. Looks different from what you might expect, yes? There are microbes down there and they are doing things. Keep in mind that this particular subglacial lake is 23 square miles big and ..... 5 feet deep.


We've had a number of students recently who are interested in Astrobiology. Astrobiologists are very interested in microbial life in extreme environments because it helps us understand what kinds of features of life on other planets we might expect to see if we were to find something.

On that note, I noticed that just the other day the Mars rover did a very nice drilling into the surface - will have to read more on this to see if there are plans to check for evidence of life. If so, you can bet that DNA-based approaches will be involved.


Tuesday, December 11, 2012

Bio321 tag clouds


For those headed into Bio321 this Spring - here are tag clouds of the content to give you a view into the course!

The lecture:

The lab:






Tuesday, July 10, 2012

Time for the beach?

http://www.motherjones.com/blue-marble/2012/07/dirtiest-beaches-nrdc



It doesn't matter how expansive the ocean is, the beaches aren't always pristine!

I was happy to see that the NC beaches were generally on the "cleaner" end. This was based on coliform bacteria present. Interesting factoid - beaches that meet minimum federal standards would still sicken 1 in 28 swimmers. Not sure how that was calculated but impressive if true.

South Padre Island in Texas was also listed as one of the cleanest - nice to hear given how many students flock down there each Spring


Wednesday, April 11, 2012

the titantic's second demise - bacteria

http://www.microbeworld.org/index.php?option=com_jlibrary&view=article&id=8629&utm_source=twitterfeed&utm_medium=twitter&utm_campaign=twitter

appropriate timing of this story coinciding with 3D release of the movie!

living in the deep ocean, chomping on iron, not a typical way to make a living but someone's got to do it....

Thursday, February 9, 2012

Looking for treasure trove of ancient microbes

Lake Vostok is a giant freshwater lake that is entombed beneath 2 miles of ice. It is estimated that this body of water has been sealed off for ~10 million years. Scientists have been drilling for a long time in hopes of reaching the water and to then be able to sample it.

What would they expect to find? Microbes would be the primary form. What would microbes that hadn't intermingled with other microbes in millions of years look like? That's the magic question. My guess is that there will be some really amazing things that come from this and that it will related to environmental metagenomic analysis

http://www.nytimes.com/2012/02/09/world/europe/russian-scientists-bore-into-ancient-antarctic-lake.html

http://www.huffingtonpost.com/2012/02/09/lake-vostok-microbes-unlikely-life_n_1264605.html (this article diverges quickly but for current students I like how it alludes to the extremophiles)

An interesting side note - the world's coldest recorded temperature was at Vostok - minus 128.6 degrees. They had to try to do most of this work in the "summer" when flight into the site was possible

Sunday, November 27, 2011

Thanksgiving micro moment

I love making a turkey soup after our main meal. I go through a ritual of boiling things down, fishing out the bones, seasoning it, etc. It takes a lot of time but man, I look forward to that first bowl of soup.

This year I made a classic microbiological mistake. After a long day I forgot and left the soup out overnight. Yes, earlier it had been boiled but since the boiling a number of us had dipped a nonsterile ladle in. Students should be able to think about how long it took their nutrient broth inoculations from this semester to go from clear to cloudy. I left the soup out for 24 hrs before realizing my mistake - the room was at a good 70 deg F (~20 degC). And yes, essentially this soup was a beautiful nutrient broth.

It broke my heart but I dumped the soup.

Bacteria always win....

Friday, September 9, 2011

Changing role of clinical work in Microbiology

http://www.microbeworld.org/index.php?option=com_jlibrary&view=article&id=7429&utm_source=twitterfeed&utm_medium=twitter&utm_campaign=twitter

Highlights:

  • advances in molecular biology are what's changing things (Microbial Renaissance #2, right?)
  • cost and accessibility of these tools is still somewhat of an issue, limiting widespread use