Enhanced shelf life and on seed stabilization of liquid bacterium inoculants

1. A method for preparing a partially desiccated liquid inoculant product, the method comprising:

providing a liquid inoculant comprising bacteria from one or more of the genera Rhizobium, Bradyrhizobium, Pseudomonas and Serratia , said bacteria grown to a substantially stationary phase; and

adding to the liquid inoculant, in an amount sufficient to partially desiccate the liquid inoculant, a desiccant treatment comprising a desiccant to form the partially desiccated liquid inoculant product, wherein the desiccant comprises from about 5% to about 50% by weight/volume of the partially desiccated liquid product and wherein the desiccant comprises one or more of trehalose, sucrose or glycerol.

2. The method according to claim 1 wherein water activity of the partially desiccated liquid inoculant product is less than about 0.990.

3. The method according to claim 1 wherein the water activity of the partially desiccated liquid inoculant product is less than about 0.980.

4. The method according to claim 1 wherein the liquid inoculant is provided by:

introducing bacteria to a liquid nutrient medium to create a bacterial culture; and

incubating the bacterial culture to allow the bacteria to grow to a substantially stationary phase thereby creating a liquid inoculant.

5. The method according to claim 4 wherein the incubating of the bacterial culture is conducted from about 2 to about 7 days.

6. The method according to claim 1 wherein the desiccant comprises a mixture of two or more of trehalose, sucrose and glycerol.

7. The method according to claim 1 wherein the desiccant is trehalose.

8. The method according to claim 7 wherein the trehalose is from about 10% to about 40% by weight/volume of the partially desiccated liquid inoculant product.

9. The method according to claim 8 wherein the trehalose is from about 20% to about 30% by weight/volume of the partially desiccated liquid inoculant product.

10. The method according to claim 6 wherein the desiccant comprises a mixture of trehalose and glycerol.

11. The method according to claim 10 wherein the trehalose is from about 5% to about 40% by weight/volume of the partially desiccated liquid inoculant product and the glycerol is from about 1% to about 10% by weight/volume of the partially desiccated liquid inoculant product.

12. The method according to claim 11 wherein the trehalose is about 20% by weight/volume of the partially desiccated liquid inoculant product and the glycerol is about 5% by weight/volume of the partially desiccated liquid inoculant product.

13. The method according to claim 1 wherein the method further comprises packaging the partially desiccated liquid inoculant product.

14. The method according to claim 13 wherein the method further comprises storing the partially desiccated liquid inoculant product.

15. The method according to claim 1 wherein the method further comprises applying the partially desiccated liquid inoculant product to a seed.

16. The method according to claim 15 wherein the desiccant is trehalose.

17. The method according to claim 16 wherein the trehalose is from about 10% to about 40% by weight/volume of the partially desiccated liquid inoculant product.

18. The method according to claim 17 wherein the trehalose is from about 20% to about 30% by weight/volume of the partially desiccated liquid inoculant product.

19. The method according to claim 15 wherein the seed comprises a seed for a leguminous plant.

20. The method according to claim 15 wherein the number of bacteria on the seed after about 10 weeks on the seed exceeds about 1 ×10 5 .

21. The method according to claim 15 wherein the method further comprises applying an extender to the seed after the partially desiccated liquid inoculant product is applied.

22. A method for preparing a dry flowable inoculant formulation, the method comprising:

providing a liquid inoculant comprising bacteria from one or more of the genera Rhizobium, Bradyrhizobium, Pseudomonas and Serratia , said bacteria grown to a substantially stationary phase; and

adding to the liquid inoculant, in an amount sufficient to partially desiccate the liquid inoculant, a desiccant treatment comprising a desiccant to form the partially desiccated liquid inoculant product; wherein the desiccant comprises from about 5% to about 50% by weight/volume of the partially desiccated liquid product, wherein the desiccant comprises one or more of trehalose, sucrose or glycerol and wherein the partially desiccated liquid inoculant product is applied to a dry carrier to form a dry flowable inoculant formulation.

23. The method according to claim 22 wherein the dry carrier is peat.

24. A method for preparing a partially desiccated liquid inoculant product, the method comprising:

first providing a liquid inoculant comprising bacteria from one or more of the genera Rhizobium, Bradyrhizobium, Pseudomonas and Serratia, said bacteria grown to a substantially stionary phase; and

second adding to the liquid inoculant, in an amount sufficient to partially desiccate the liquid inoculant, a desiccant treatment comprising a desiccant to form the partially desiccated liquid inoculant product, wherein the desiccant comprises from about 5% to about 50% by weight/volume of the partially desiccated liquid product and wherein the desiccant comprises one or more of trehalose, sucrose or glycerol;

third allowing the partially desiccated liquid inoculant product to equilibrate for a predetermined amount of time before applying the partially desiccated liquid inoculant product to seed; and

fourth applying the partially desiccated liquid inoculant product to a seed after the predetermined amount of time.

25. The method of claim 24 wherein the predetermined amount of time is about 7 days.