Stable dry powder composition comprising biologically active microorganisms and/or bioactive materials and methods of making

A stable dry composition comprising (i) a live bioactive microorganism or material as fresh, frozen or dry powder, (ii) at least two stabilizer agents, and (iii) at least two protective agents, wherein the live bioactive microorganism or material is selected from the group consisting of bacteria and viruses, wherein the composition is prepared according to a method comprising:

• (a) combining the live bioactive microorganism or material, the at least two dry stabilizer agents and the at least two dry protective agents in an aqueous solvent, whereby a mixture is obtained;
• (b) cooling the mixture from step (a) to a temperature no more than 10° C. above the freezing temperature of the mixture, whereby the mixture is cooled;
• (c) primary drying the cooled mixture from step (b) by evaporation under vacuum of 1-5 Torr and at a temperature above the freezing temperature of the mixture, whereby the mixture is dried;
• and
• (d) secondary drying the dried mixture from step (c) under vacuum of less than 1 Torr and at a temperature of 20° C. or more for a time sufficient to reduce the water activity (Aw) of the mixture to 0.3 or less, whereby the composition is prepared.