Note: Descriptions are shown in the official language in which they were submitted.
i~5~D~5 S
Back~round, Summar~ and Detailed Des'cription of the Invention
This invention pertains to the processing of active
microorganisms, and more particularly to a method of establishing
reversible dormancy in such organisms.
Various kinds of microorganisms are employed today for
many different beneficial purposes. For example, some kinds,
such as those derived from the excre~a or rumen contents of
certain animals, are used, among other things, as constituents
in so-called soil i~provers. Many other specific uses of micro-
organisms are, of course, known.
A problem heretofore, however, has been the difficultyof successfully and economically storing such organisms over
extended periods of time in a condition ready for use.
A general object of the present invention, therefore,
is to provide a novel method of preparing different kinds of
microorganisms for satisfactory long term storage.
More specifically, an object of the invention is to
provide such a method whereby microorganisms can easily be
placed in a state of reliable reversible dormancy, out of which
the organisms may be reactivated at any selected later time.
These highly desirable objectives are readily attained
by the method of the present invention which contemplates the
very simple yet unique procedure of preparing a wet mixture
containing, essentially, and in particular critical proportions,
three constituents: a population of the desired microorganisms,
a suitable liquid carrier (such as water or oil or another), and
particles of diatomaceous earth. This procedure is applicable
to any type of microorganism.
The relevant proportions of the'above constituents
3Q which must be maintained for succes'sful pract'ice of the invention
are'as follows: in the final mixture, the'weight of diatomaceous
earth particles must be in the range of about 25 percent to
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1050455
about 400 percent of the weight of the liquid carrier in the
mixture; and, the weight of the microorganisms should not exceed
about 15 percent of the total weight of the mix~u~e. With
respect to the relative p-;oportions of diatomaceous earth parti-
cles and a liquid carrier, a very satisfactory, and preferred,
relationship is one where the weight of the particles is about
65-70 percent of the weight of the carrier.
On preparation of a mixture as above des~ribed, the
active microorgan~sms therein become dormant, but reactivatable
at any later time. By enclosing the prepared mixture in a
suitable moisture-impervious sealed container, such as a sealed
plastic pail or tub, to maintain the moisture content of the
mixture substantially constant, the microorganisms can be held
in reversible donmancy indefinitely. Reactivation is accomplish-
ed simply by unsealing the mixture, and increasing the amount of
liquid carrier therein to where the carrier has a weight greater
than four times that of the diatomaceous earth particles.
By way of example, a population of microorganisms
contained in animal excreta, and intended for later use as a
plant and soil nourisher, is successfully made dormant for long-
term storage purposes in the following manner. One-quarter
pound of fresh manure, along with one-quarter pound of fresh
urine from a heifer are blended into 100 lbs. of water (liquid
carrier). This blend is then allowed to sit in a tank for a
period of about four days -- such sitting allowing the natural
assimilation into the water of microorganisms from the manure
and urine.' After this period, the liquid and solid constituents
of the'blend are'suitably separated as by siphoning off the
former. Sixty-seven lbs. o~ commercially available diatomaceous
earth particles are'then added to this separated liquid consti-
tuent to produce the final mixture.' Such diatomaceous earth is
normally powder-like in ~orm, and typically contains particles
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1050~55
having mesh sizes in the range of about 200-400 mesh.
This final mixture, it will be noted, contains less
than 15 percent (by weight) of microorganisms (from the manure
and urine). Further, the weight of the dia~omaceous earth
particles in the mixture is about 67 percen~ of the weight of
the water therein. Thus, the mixture fits ~he criteria set
forth above. ~onsequently, and as is desired, the manure-
carried and urine-carried microorganisms which have been assimi-
lated in the water become dormant in the mixture.
For long-term storage purposes, the mixture is sealed
in a moisture-impervious plastic container. Such sealing main-
tains the moisture content of the mixture substantially constant,
and thereby maintains a state of dormancy in the microorganisms.
This state can be held ind finiteIy.
When it is desired to reactivate the microorganisms
for use, this is done simply by opening the container, and by
then adding the mixture to enough new water whereby the combined
weight of the original water in the mixture, plus the new water,
is greater than four times t~at of the diatomaceous earth parti-
cles in the'mixture.
The present invention, thus, affords a simple methodof establishing reversible dormancy in microorganisms. Within
~he limits defined above,' it is apparent that various specific
storable'mixtures, wherein microorganic dormancy is attained, ''
can be'prepared in accordance with the'steps of the invention.
Any suitable'liquid carrier may be'used. '
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