Influencing Factors to Biodispersant Biosynthesis of Bacillus subtilis S343

Biodispersants are a group of compounds containing surface-active molecules (hydrophilic and hydrophobic radicals). They are widely researched and applied in many industries, biological control agents in agriculture and environmental remediation. Bacillus subtilis strain S343, isolated from ferns, is one of the most effective biodispersant producers. Nutritional factors and fermentation conditions affecting the yield of biodispersants were studied. The fermentation medium contains carbon source which is soluble starch (1% w/v), nitrogen source which is yeast extract (0.5% w/v), some minerals and Ethylenediaminetetraacetic Acid (EDTA) (0.05 g/L), pH 7, 0 and incubation under shaking conditions at 35 °C for 6 days was found to maximize biodispersant production. The crude biodispersants produced reached the highest level of 18.9 g/L, oil spreading activity reached 75 mm, and the ability to collapse in just 1 second after contact. In particular, the E24 emulsification index is high at 60% and the surface tension of the crude biodispersant can be reduced to 30.92 ± 2.0 compared to the water sample of 71.2 mN/m. The study shows that Bacillus subtilis S343 strain is a potential source for producing biodispersants for application in the fields of environment, biomedicine, agriculture and industry.