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  • From: Soil Doctor <soildoctor.org@gmail.com>
  • To: permaculture@lists.ibiblio.org
  • Subject: [permaculture] "Weird" Science - Microbes and Soil
  • Date: Fri, 3 Dec 2010 10:43:42 -0600

Thanks for posting this Keith. I've been following Dr. Bassler's research
for a few years now. In her TED video she does start off by pointing out
that in terms of cell counts our bodies are composed of 90% microbial cells
and 10% human. If we look at DNA material, our bodies contain 99% microbial
DNA and 1% human. We would die without the microbes in us and on us. In my
workshops I say that each one of us is a symbiotic ecosystem based on
mutualism.

However, I think people sometimes miss the agricultural importance of Dr.
Bassler's central work on Quorum Sensing (the TED video is about this). Over
the past 15 years Dr. Bassler and her MIT team discovered that all bacteria
species "speak" in 2 chemical languages: one language is a private language
only understood within the specific bacteria species and the other language
is the Esperanto common language understood by all bacteria species. Until
Dr. Bassler's work, microbiologists couldn't understand how some bacterial
mixtures which contained pathogens like E. Coli would not show E. Coli
virulence and other bacterial mixtures which contained E. Coli the E. Coli
would be very active and engaging in a virulent attack. Dr. Bassler figured
out that the E. Coli were communicating to other E. Coli using the private E.
Coli chemical language AND communicating to ALL of the other bacterial
species using the common bacterial language. Only when the E. Coli number of
individual bacterium RELATIVE to the total of all bacteria species numbers
was high enough in E. Coli to give the E. Coli a fighting chance of winning
would the E. Coli "switch" on and become virulent. From an evolutionary
standpoint this makes sense. Why would a pathogenic organism species make an
attempt to create dis-ease (which entails a use of valuable energy) when it
is completely outnumbered by other microbial species who may be potential
predators who function as a check and balance against the dis-ease.

This has profound implications for farming and ranching.

Quorum Sensing happens in soils, composts, compost teas and extracts. From a
conventional agricultural model we think we have to eradicate and attack
plant pathogens using various biocides. I'll go so far to say that this way
of thinking is also prevalent in organic farming and in permaculture. Whether
our biocides are synthetic "chemical" pesticides or "organic" home-made
pesticides, the thinking behind their use is the same: if the pathogen is
present (even in a neighbour's field) we lay down a biocide attacking the
pathogen. Our biocides, whether a commercial Syngenta pesticide or a
homemade permaculture recipe for powdery mildew sulphur containing "organic"
biocide, kills BOTH the bad-guy pathogen microbes and the good-guys. Problem
here is that the bad-guys usually (not always but usually) reproduce more
quickly and come back before the good-guy microbes. Quorum Sensing points
to a fundamentally new way of thinking about this in our farms. We need to
increase the ratio of good-guy microbes in the soil and on the plant surfaces
in relation to the "bad-guy" pathogen microbes. Research on plant pathogen
suppression with composts backs this up. It's the amount of a plant pathogen
species #s in a compost relative to the total pile of microbes that
determines whether the plants will develop the disease.

Doug
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Doug Weatherbee, M.A.
Certified Soil Foodweb Advisor
http://soildoctor.org

San Miguel de Allende, GTO
Mexico
415.152.3410 (San Miguel #)
310.359.8549 (U.S.A #)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



> ------------------------------
>
> Message: 2
> Date: Wed, 01 Dec 2010 00:19:38 -0500
> From: Keith Johnson <keithdj@mindspring.com>
> To: BPG <bloomington_permaculture_guild@lists.riseup.net>,
> Permaculture ibiblio <permaculture@lists.ibiblio.org>
> Subject: [permaculture] "Weird" Science - Microbes and Soil
> Message-ID: <4CF5DAEA.4000401@mindspring.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
>
> "Weird" Science #5: Microbes and Soil
>
> <http://johnscorner.blogspot.com/2010/11/weird-science-5-microbes-and-soil.html>
>
> You'll love the TED video that accompanies this story.
>
> (Snip)
> The human body has about a trillion cells in it. And those trillion
> cells host--either in you or on you--about 10 trillion bacteria. You
> have about 30,000 genes in you; the bacteria you host have about 100
> times the amount of genetic material or information. "So," says
> Bassler, "when I look at you, I think of you as 1 or 10 percent human
> and either 90 or 99 percent bacterial."
>
> In the same way we humans have domesticated and now farm plants and
> animals for our benefit, so (say leading soils researchers) plants
> have established interdependent, symbiotic relationships with most of
> the protozoa, earthworms, arthropods, algae, bacteria, and fungi that
> surround their roots. The plants send food (about half of all the
> carbohydrates and other nutrients they produce) down to their roots
> . . . and then, through their roots, they /exude/ these nutrients (in
> a liquid called /exudate/), into the soil. This exudate, in turn,
> feeds the bacteria and other organisms that live in the rhizosphere
> <http://en.wikipedia.org/wiki/Rhizosphere> (the area of the roots).
> (Snip)
>
> Read the complete set at
> http://johnscorner.blogspot.com/search?q=Weird+science
>
> --
>
> Keith Johnson
> "Be fruitful and mulch apply."
> Permaculture Activist Magazine
> PO Box 5516, Bloomington, IN 47407
> (812) 335-0383
> - Permaculture Activist <http://www.permacultureactivist.net/>
> - Permaculture Trading Post <http://www.permaculturetradingpost.com/>
> - Patterns for Abundance Design & Consulting
> <http://www.permacultureactivist.net/design/Designconsult.html>
>
> - Local Growers Guild <http://www.localgrowers.org/>
> - Permaculture & Regenerative Design News Blog
> <http://kjpermaculture.blogspot.com/>
> - Permaculture Politics Blog <http://permaculturepolitics.blogspot.com/>
>
> - Transition Indiana <http://transitionindiana.blogspot.com/> - Blog
> <http://transitionindiana.blogspot.com/>
>
> - TransitionBloomington.org <http://transitionbloomington.org/>
>
> - TransitionBloomington.ning <http://transitionbloomingtonind.ning.com/>
> - The Gardeners' World Blog <http://theecosystem.blogspot.com/>
> - Renaissance Farm and Permaculture Center
> <http://bloomingtongrowers.locallygrown.net/growers/show/212>
> - Bloomington Permaculture Growers Cooperative
> <http://bloomingtongrowers.locallygrown.net/>
> - Bloomington Permaculture Guild Blog
> <http://bloomingtonpermacultureguild.blogspot.com/> - Calendar
> <http://my.calendars.net/bloomingtonpccal/>
> - Switch to Solar Power the Easy Way
> <http://www.jointhesolution.com/KeithJ-SunPower>
>





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