This invention provides a Bacillus sicca Z4, Bacillus siamensis The strain Z4 was deposited on March 3, 2026, at the China General
Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 37830, located at Institute of
Microbiology, Chinese Academy of Sciences, No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing. The optimal
fermentation medium for strain Z4 was 1000 mL of water, with
yeast extract at 15 g / L,
maltose at 20 g / L, and
sodium chloride at 4 g / L. The optimal
fermentation conditions were: 1% inoculum in a 250 mL
Erlenmeyer flask (75 mL), temperature 35℃, pH 7, rotation speed 289 r / min, and incubation time 18 h. Strain Z4 antagonized the growth and
spore germination of *
Spodoptera litura*, the causal agent of
sorghum smut. The aseptic
fermentation filtrate of strain Z4, diluted 10-20 times, could be used to accelerate
sorghum seed
germination and emergence. The
fermentation broth of strain Z4, diluted 10-100 times, could be used for the control of
sorghum smut. This invention provides new biocontrol resources for the prevention and control of sorghum
smut and other diseases.