Re: [compost_tea] Re: MICROBIOLOGY TESTING of COMPOST TEAS
I somehow missed Dennis' last post about critters depositing coliforms on
the compost pile.
First of all, the term "coliforms" include many bacterial species that are
highly beneficial to both plants and to people. You have to have them in your
digestive system in order to digest properly. You should get that group of
bacteria back in your digestive system after antibiotic treatment. Where you
get them from is by eating green leafy vegetables, with the good guys, which
include some coliforms.
So, getting freaked about coliform counts is just not reasonable.
For example, Klebsiella planticola, found on all healthy plant surfaces is a
coliform, but helps plants grow, as well as people digest. This bacterium
is always present in healthy soil and on healthy plant material.
The coliforms we are concerned about are the disease-causers, the pathogens.
But again, they only cause disease when they find the right habitat. When
a human digestive system is healthy, disease is not typically going to occur.
The conditions that fall into outside the usual category are:
- when you get a huge inoculum load - that means hundreds of thousands of
individuals per bite - will those disease-causers be able to overwhelm a healthy
system.
- when you are already stressed. Old people, already stressed by a number
of problems, and children, stressed by the demands of growing, fall into this
category of already stressed. Already stressed means there's a habitat
available for the pathogens to grow and cause problems.
- when the pathogen makes a toxin that takes out the healthy sets of
bacteria, resulting in no-competition, open habitat for the pathogen to grow.
We assess the POTENTIAL for any of the three general conditions to be met by
looking for fecal E. coli. Not just any old E. coli, but FECAL E. coli. E.
coli O157 strains are all in that category of fecal E. coli.
Just because you find a fecal E. coli does not mean you have any of the
pathogens present, it just means the potential exists for them to be present,
sooner or later. And that means, find the source of the problem and fix it NOW.
Before there's a problem.
If there is E. coli in compost or water or food, figure out what isn't being
done right, and fix it.
E. coli in tea? Fix the source of contamination. In the meantime, don't
put the tea or compost, or whatever on any food crop. Make sure that pathogen
contaminated material goes on something that isn't going to be eaten
straight.
Typically, if a compost is aerobic, and you have the microbial habitats
already "filled up", and you have active beneficials, defending their home-sites,
condominiums and housing developments, there isn't any habitat for an added
organism to get a foothold, then even if a bird lands and poops, or a mouse,
or whatever poops, the pathogens aren't going to take over the pile.
Only when the pile has gotten too hot, and the beneficials were killed or
put-to-sleep will something from bird poop be able to take over the pile. Only
when the pile went anaerobic, and the good guy were put to sleep or killed
will a pathogen be able to take over.
So, again, composting properly results in protection from things happening
that you don't want to have happening.
Plate counts cannot give you the information you need to know.
Direct microscope ACTIVITY determinations assess what you need to know with
respect to having the active organisms to defend your pile. total bacterial
and fungal biomass tell you if you will have all those habitats occupied,
even as temperature and moisture change, and some species go to sleep, while
others wake up.
Elaine R. Ingham
Soil Foodweb Inc., Corvallis, Oregon
Soil Foodweb Inc., Port Jefferson, New York
Soil Foodweb Institute, Lismore Australia
Soil Foodweb Institute Cambridge, New Zealand
Laboratorios de Soil Foodweb, Culiacan, Mexico
Soil Foodweb Inc., Jerome, Idaho
Soil Foodweb Inc., South Africa
Received on Sun Dec 26 2004 - 17:41:05 EST
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