Characterization and biomedical application of Tetradecamethylcycloheptasiloxane, a silicone-type biosurfactant produced by Streptomyces castaneoglobisporus AJ9 isolated from solar salt works

Tetradecamethylcycloheptasiloxane (C₁₄H₄₂O₇ Si₇ ), a biosurfactant, was extracted by acid precipitation method from the haloalkaliphilic actinomycetes, Streptomyces castaneoglobisporus AJ9 (Gene Bank KC603900.1) and characterized by GC-MS analysis. The purified biosurfactant could effectively degrade dyes such as orange MR, direct violet, cotton red, reactive yellow and nitro green. Antimicrobial screening results showed that biosurfact ants could effectively control bacterial pathogens such as Staphylococcus aureus and Vibrio parahaemolyticus and fungal pathogens such as Fusarium sp. and Penicillium sp. Even a small diminutive quantity of biosurfactant (100 μg) could totally block the multiplication of White Spot Syndrome Virus (WSSV) in shrimp in vivo. The suppression of cancer cells in vitro by the biosurfactant was 74 % as confirmed by Response Surface Methodology (RSM) and residual plot analysis. Wheat bran, groundnut oilcake and oilseed cake seem to enhance biosurfactant production.