The invention provides methods for providing Bacillus spores for application to agricultural soil or plant material. The methods comprise suspending the Bacillus spores in a liquid consisting essentially of water and an organic acid, including acetic acid, wherein the acid lowers the pH so that the spores are inhibited from germination and growth and so that growth of unwanted microorganisms in the suspension is prevented. Compositions formed according to the methods of the invention are also provided.
