Stable inoculant compositions and methods for producing same
The present disclosure provides stable inoculant compositions and methods for enhancing the survival and/or stability of microorganisms in an inoculant composition. In some embodiments, the microorganisms in an inoculant compositions are stabilized by the presence of one or more maltodextrins having a dextrose equivalent value of about 15 to about 20.
1. An aqueous inoculant composition comprising:
one or more maltodextrins having a dextrose equivalent value of about 15 to about 20;
maltose; and
one or more strains of Gram-negative bacteria,
said one or more maltodextrins and said maltose comprising about 35 to about 65% of said inoculant composition (w/w, based upon the total weight of said inoculant composition).
2. The aqueous inoculant composition of claim 1 , in which said one or more maltodextrins and said maltose are present in a maltodextrin:maltose ratio of about 15:85 to about 85:15.
3. The aqueous inoculant composition of claim 1 , in which said one or more maltodextrins and said maltose are present in a maltodextrin:maltose ratio of about 35:65 to about 65:35.
4. The aqueous inoculant composition of claim 1 , in which said one or more strains of Gram-negative bacteria is/are present in a concentration ranging from about 1×10 1 to about 1×10 15 colony-forming units per gram of said inoculant composition.
5. The aqueous inoculant composition of claim 1 , in which said one or more strains of Gram-negative bacteria is/are present in a concentration ranging from about 1×10 4 to about 1×10 11 colony-forming units per gram of said inoculant composition.
6. The aqueous inoculant composition of claim 1 , in which said one or more Gram-negative bacteria is/are present at a concentration of at least 1×10 7 colony-forming units per gram of said inoculant composition.
7. A method comprising drying the aqueous inoculant composition of claim 1 to produce a non-aqueous inoculant powder or granule.
8. The method of claim 7 , in which said aqueous inoculant composition is spray-dried, freeze-dried or spray-freeze-dried to produce said non-aqueous inoculant powder or granule.
9. A method comprising applying the aqueous inoculation composition of claim 1 to a plant or plant part.
10. A method comprising applying the non-aqueous inoculant powder or granule of claim 7 to a plant or plant part.
11. A method comprising applying the aqueous inoculation composition of claim 1 to a plant growth medium.
12. A method comprising applying the non-aqueous inoculant powder or granule of claim 7 to a plant growth medium.
13. A coated plant seed, comprising:
a plant seed; and
a coating that covers at least a portion of an outer surface of said plant seed,
said coating comprising the aqueous inoculant composition of claim 1 .
14. A coated plant seed, comprising:
a plant seed; and
a coating that covers at least a portion of an outer surface of said plant seed,
said coating comprising the non-aqueous inoculant powder or granule of claim 7 .
15. A kit comprising a plurality of plant seeds that have been treated with the aqueous inoculant composition of claim 1 .
16. A kit comprising a plurality of plant seeds that have been treated with the non-aqueous inoculant powder or granule of claim 7 .