Abstract: By using the methods of flow point, biocompatibility assay, orthogonal test etc, a variety of screening tests were conducted for all of the adjuvants added in the formulation of suspension concentrate with a strain P1 of Paenibacillus polymyxa (P1-SC). The results showed that, when the formulation of P1-SC was prepared as:P1 was 10% (≥ 10.18 lg cfu/g), both wetting dispersant of 500^# and MOA-7 were 2.5%, thickeners of magnesium aluminum silicate and xanthan gum were 0.75% and 0.15% respectively, antiseptic agent C25 was 0.20%, antifreeze of propanol was 3%, silicone anti-foaming agent was 0.3%, and finally adding soft water to make it up to 100%, the viable P1 spores in P1-SC were ≥ 9.18 lgcfu/mL, the fineness (through 75 µm sieve) was ≥ 95%, the pH value was 5.0-8.0, the amount of long-lasting foaming (after 1 min) was ≤ 30 mL, the residual mass after dumping was ≤ 5.0%, and the residual mass after washing was ≤ 0.5%, the suspension rate was ≥ 90%, which means it reaches the detection standards of an enterprise for a SC formulation. Meanwhile, the shelf life of P1 spores in prepared P1-SC was measured under different temperatures. A 6-month storage test revealed that the number of viable P1 decreased about 6% when stored at 45℃,however, it did not change much when stored at 4℃ and 25℃, respectively.

Key words: Paenibacillus polymyxa, suspension concentrate, formulation, screen, stability