Quorum Sensing

Eos of the Eons · 7th August 2008, 10:17 PM

Sounds like woo woo hogwash, but this is really cool:

http://www.ncbi.nlm.nih.gov/pubmed/11544353

Bacteria do communicate with each other. I'm surprised I hadn't heard of this before, so I had to share.

I'm not sure if it is spelled out online, but I saw the person who coined the term "quorum sensing" in a documentary last night on PBS. She explained that the bacteria didn't respond a certain way to each other until a certain number became present in an area. The bacteria she was studying didn't glow until a "quorum" was present. The party didn't start until a certain number of bacteria came about to play.

I used to take minutes at meetings, most of which didn't start until there was a quorum. Get it?

Quote:

The minimal number of officers and members of a committee or organization, usually a majority, who must be present for valid transaction of business.

I find that totally amusing.

-Geekout

sanguine · 8th August 2008, 12:19 PM

Yeah, definitely not woo. I have worked on quorum sensing.

It's fascinating, actually, as it can affect everything from bacterial growth in open culture to things like whether the fungus C. albicans (pathogenic agent in Candidiasis, aka Thrush) is in its hyphael or "free cell" growth mode -- which has immediate implications for someone who has a Candida infection.

Of course, as it's not woo woo hogwash, it's already been tested and comes down to very straightforward mechanisms. For example, Candida's quorum sensing occurs through the small molecule farnesol, which each individual Candida cell pumps out into the environment. If enough Candida are around, there will be a ton of that small molecule in their immediate environment, the cells each detect this, and they shift growth states.

(Of course, you then need to try and experimentally determine /why/ it's valuable for the organism to do this, which is a whole separate and fascinating line of inquiry.)

bokonon · 8th August 2008, 01:06 PM

I haven't looked at the articles yet, but it sounds like that could be a step on the way from single-celled to multicellular organisms.

ETA: "The evolution of quorum sensing systems in bacteria could, therefore, have been one of the early steps in the development of multicellularity."

I guess I wasn't the first to think of that...

sanguine · 8th August 2008, 02:10 PM

Originally Posted by bokonon

I haven't looked at the articles yet, but it sounds like that could be a step on the way from single-celled to multicellular organisms.

ETA: "The evolution of quorum sensing systems in bacteria could, therefore, have been one of the early steps in the development of multicellularity."

I guess I wasn't the first to think of that...

You want to read about Dictyostelium. Really cool stuff.

Eos of the Eons · 8th August 2008, 05:02 PM

Very exciting. I'm totally jealous of anyone who gets to work on it. Well, I'm totally jealous of anyone working on any research for that matter.

I can't wait to hear more of any news on this.

7th August 2008, 10:17 PM	#1
Eos of the Eons Mad Scientist Join Date: Jul 2003 Location: Alberta Posts: 13,894	Quorum Sensing Sounds like woo woo hogwash, but this is really cool: http://www.ncbi.nlm.nih.gov/pubmed/11544353 Bacteria do communicate with each other. I'm surprised I hadn't heard of this before, so I had to share. I'm not sure if it is spelled out online, but I saw the person who coined the term "quorum sensing" in a documentary last night on PBS. She explained that the bacteria didn't respond a certain way to each other until a certain number became present in an area. The bacteria she was studying didn't glow until a "quorum" was present. The party didn't start until a certain number of bacteria came about to play. I used to take minutes at meetings, most of which didn't start until there was a quorum. Get it? Quote: The minimal number of officers and members of a committee or organization, usually a majority, who must be present for valid transaction of business. I find that totally amusing. -Geekout
	__________________ Motion affecting a measuring device does not affect what is actually being measured, except to inaccurately measure it. the immaterial world doesn't matter, cause it ain't matter-Jeff Corey my karma ran over my dogma-vbloke The Lateral Truth: An Apostate's Bible Stories by Rebecca Bradley, read it!

8th August 2008, 12:19 PM	#2
sanguine Thinker Join Date: Jul 2005 Posts: 206	Yeah, definitely not woo. I have worked on quorum sensing. It's fascinating, actually, as it can affect everything from bacterial growth in open culture to things like whether the fungus C. albicans (pathogenic agent in Candidiasis, aka Thrush) is in its hyphael or "free cell" growth mode -- which has immediate implications for someone who has a Candida infection. Of course, as it's not woo woo hogwash, it's already been tested and comes down to very straightforward mechanisms. For example, Candida's quorum sensing occurs through the small molecule farnesol, which each individual Candida cell pumps out into the environment. If enough Candida are around, there will be a ton of that small molecule in their immediate environment, the cells each detect this, and they shift growth states. (Of course, you then need to try and experimentally determine /why/ it's valuable for the organism to do this, which is a whole separate and fascinating line of inquiry.)
sanguine Thinker Join Date: Jul 2005 Posts: 206

8th August 2008, 01:06 PM	#3
bokonon Illuminator Join Date: Aug 2007 Posts: 4,444	I haven't looked at the articles yet, but it sounds like that could be a step on the way from single-celled to multicellular organisms. ETA: "The evolution of quorum sensing systems in bacteria could, therefore, have been one of the early steps in the development of multicellularity." I guess I wasn't the first to think of that...
bokonon Illuminator Join Date: Aug 2007 Posts: 4,444	Last edited by bokonon; 8th August 2008 at 01:08 PM.

8th August 2008, 02:10 PM	#4
sanguine Thinker Join Date: Jul 2005 Posts: 206	Originally Posted by bokonon I haven't looked at the articles yet, but it sounds like that could be a step on the way from single-celled to multicellular organisms. ETA: "The evolution of quorum sensing systems in bacteria could, therefore, have been one of the early steps in the development of multicellularity." I guess I wasn't the first to think of that... You want to read about Dictyostelium. Really cool stuff.
sanguine Thinker Join Date: Jul 2005 Posts: 206

8th August 2008, 05:02 PM	#5
Eos of the Eons Mad Scientist Join Date: Jul 2003 Location: Alberta Posts: 13,894	Very exciting. I'm totally jealous of anyone who gets to work on it. Well, I'm totally jealous of anyone working on any research for that matter. I can't wait to hear more of any news on this.
	__________________ Motion affecting a measuring device does not affect what is actually being measured, except to inaccurately measure it. the immaterial world doesn't matter, cause it ain't matter-Jeff Corey my karma ran over my dogma-vbloke The Lateral Truth: An Apostate's Bible Stories by Rebecca Bradley, read it!