Agglomerated microbiological media

1. A method of making a flowable, dried agglomerated nutrient medium, the method comprising:

introducing a nutrient component comprising a powdered nutrient, and an agglomeration liquid, into an agglomerator comprising a flow-through-type agglomeration chamber and a mixing blade;

wherein the nutrient component facilitates the growth of a microorganism;

wherein the agglomeration liquid is introduced as an atomized spray;

wherein introducing the nutrient component into the agglomeration chamber comprises introducing the nutrient component at a feed rate of about 50 kg/hour to about 1000 kg/hour;

wherein introducing the agglomeration liquid into the agglomeration chamber comprises introducing the agglomeration liquid at a spray rate about 15 kg/hour to about 300 kg/hour;

wet-massing the nutrient component with the agglomeration liquid in the agglomeration chamber for a predetermined period of time to form agglomerated nutrient medium particles;

exposing the agglomerated nutrient medium particles to drying conditions for a period of time to form the dried, agglomerated nutrient medium;

wherein the mixing blade is rotated at a blade rotation rate of about 500 rpm to about 4000 rpm;

wherein exposing the agglomerated nutrient medium to drying conditions comprises exposing the agglomerated nutrient medium to a predetermined temperature about 60° C. to about 85° C.;

wherein the feed rate, the spray rate, the blade rotation rate, and the predetermined temperature are selected to produce a dried agglomerated nutrient medium having particles of a first particle size distribution range of about 105 microns to about 2000 microns; and

isolating a subpopulation of the particles, the subpopulation having a second particle size distribution range that is narrower than the first particle size distribution range, the second particle size distribution range being about 149 microns to 1000 microns.

2. The method of claim 1 , wherein the agglomeration liquid consists of water.

3. The method of claim 1 , wherein the agglomeration liquid comprises a solvent having a dissolved nutrient that facilitates the growth of a microorganism.

4. The method of claim 1 , wherein introducing a nutrient component comprises introducing a substantially uniform mixture of two or more powdered nutrients.

5. The method of claim 1 :

wherein introducing a nutrient component into the agglomeration chamber comprises introducing the nutrient component at a feed rate of about 50 kg/hour to about 1000 kg/hour;

wherein introducing an agglomeration liquid into the agglomeration chamber comprises introducing the agglomeration liquid at a spray rate of about 15 kg/hour to about 300 kg/hour;

wherein the agglomerator further comprises a mixing blade, wherein the mixing blade is rotated at a blade rotation rate of about 500 rpm to about 4000 rpm;

wherein exposing the agglomerated nutrient medium to drying conditions comprises exposing the agglomerated nutrient medium to a predetermined temperature of about 60° C. to about 85° C.;

wherein the feed rate, the spray rate, the blade rotation rate, and the predetermined temperature are selected to produce a dried agglomerated nutrient medium having a preselected mean water content of less than 5 weight percent.

6. The method of claim 1 :

wherein introducing a nutrient component into the agglomeration chamber comprises introducing the nutrient component at a feed rate of about 50 kg/hour to about 1000 kg/hour;

wherein introducing an agglomeration liquid into the agglomeration chamber comprises introducing the agglomeration liquid at a spray rate about 15 kg/hour to about 300 kg/hour;

wherein the agglomerator further comprises a mixing blade, wherein the mixing blade is rotated at a blade rotation rate of about 500 rpm to about 4000 rpm;

wherein exposing the agglomerated nutrient medium to drying conditions comprises exposing the agglomerated nutrient medium to a predetermined temperature about 60° C. to about 85° C.;

wherein the feed rate, the spray rate, the blade rotation rate, and the predetermined temperature are selected to produce a dried agglomerated nutrient medium having a gravity-packed density of 0.2 to 0.5 grams per cubic centimeter.

7. The method of claim 1 , wherein one or more powdered nutrient is selected from the group consisting of a protein, a carbohydrate, a salt and a mixture of any two or more of the foregoing powdered nutrients.

8. The method of claim 1 , further comprising the step of subjecting the dried agglomerated nutrient medium to a process that reduces the number of viable microorganisms in the dried agglomerated nutrient medium.

9. The method of claim 8 , wherein subjecting the dried agglomerated nutrient medium to a process that reduces the number of viable microorganisms comprises exposing the dried agglomerated nutrient medium to ionizing radiation or to ethylene oxide vapor.