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;
one or more disaccharides;
one or more hygroscopic polymers selected from the group consisting of carboxymethyl celluloses, gums and polyvinyl alcohols; and
one or more strains of Gram-negative bacteria, in which one or more of the following is true:
said one or more maltodextrins and said one or more disaccharides are present in a maltodextrin: disaccharide ratio of about 35:65 to about 65:35;
said one or more disaccharides comprises maltose;
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 aqueous inoculant composition.
2. The aqueous inoculant composition of claim 1 , in which said one or more maltodextrins and said one or more disaccharides are present in a maltodextrin: disaccharide ratio of about 35:65 to about 65:35.
3. The aqueous inoculant composition of claim 1 , in which said one or more disaccharides comprises maltose.
4. The aqueous inoculant composition of claim 1 , in which said one or more hygroscopic polymers comprises a carboxymethyl cellulose.
5. The aqueous inoculant composition of claim 1 , in which said one or more hygroscopic polymers comprises one or more gums.
6. The aqueous inoculant composition of claim 1 , in which said one or more hygroscopic polymers comprises xantham gum.
7. The aqueous inoculant composition of claim 1 , in which said one or more hygroscopic polymers comprises a polyvinyl alcohol.
8. The aqueous inoculant composition of claim 1 , in which said one or more hygroscopic polymers comprises a carboxymethyl cellulose and a polyvinyl alcohol.
9. The aqueous inoculant composition of claim 1 , in which said one or more hygroscopic polymers comprises about 0.1 to about 5% of said aqueous inoculant composition, by weight, based upon the total weight of said aqueous inoculant composition.
10. The aqueous inoculant composition of claim 1 , in which said one or more hygroscopic polymers comprises about 0.1 to about 1% of said aqueous inoculant composition, by weight, based upon the total weight of said aqueous inoculant composition.
11. The aqueous inoculant composition of claim 1 , in which said one or more strains of Gram-negative bacteria is/are present in a concentration of at least 1×10 5 colony-forming units per gram of said inoculant composition.
12. 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.
13. The aqueous inoculant composition of claim 1 , further comprising one or more surfactants.
14. The aqueous inoculant composition of claim 13 , in which said one or more surfactants comprises one or more siloxanes.
15. The aqueous inoculant composition of claim 13 , in which said one or more surfactants comprises one or more trisiloxanes.
16. A method comprising applying an aqueous inoculant composition to a plant or plant part, said aqueous inoculant composition comprising:
one or more maltodextrins having a dextrose equivalent value of about 15 to about 20;
one or more disaccharides;
one or more hygroscopic polymers; and
one or more strains of Gram-negative bacteria.
17. A method comprising introducing an aqueous inoculant composition into a plant growth medium comprising soil, said aqueous inoculant composition comprising:
one or more maltodextrins having a dextrose equivalent value of about 15 to about 20;
one or more disaccharides;
one or more hygroscopic polymers; and
one or more strains of Gram-negative bacteria.
18. 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 an aqueous inoculant composition that comprises:
one or more maltodextrins having a dextrose equivalent value of about 15 to about 20;
one or more disaccharides;
one or more hygroscopic polymers; and
one or more strains of Gram-negative bacteria.
19. A kit comprising a plurality of plant seeds that have been treated with an aqueous inoculant composition that comprises:
one or more maltodextrins having a dextrose equivalent value of about 15 to about 20;
one or more disaccharides;
one or more hygroscopic polymers; and
one or more strains of Gram-negative bacteria.
20. A method of improving the stability of a Gram-negative bacteria in an aqueous composition, said method comprising introducing into said composition:
one or more maltodextrins having a dextrose equivalent value of about 15 to about 20;
one or more disaccharides; and
one or more hygroscopic polymers selected from the group consisting of carboxymethyl celluloses, gums and polyvinyl alcohols, in which one or more of the following is true:
said one or more maltodextrins and said one or more disaccharides are introduced into said composition in a maltodextrin: disaccharide ratio of about 35:65 to about 65:35;
said one or more disaccharides comprises maltose.