SYSTEMATIC OPTIMIZATION OF CULTURE CONDITIONS FOR HIGH-YIELD BIOSURFACTANT SYNTHESIS BY STUTZERIMONAS STUTZERI PS1

Biosurfactants are versatile compounds produced by bacteria that have several industrial and biomedical applications. In the present study, 12 bacterial strains were isolated from oil-contaminated soil and subjected to primary screening for biosurfactant activity. Initial screening on a CTAB-MB agar plate showed blue halos, confirming the glycolipid nature of the produced biosurfactant. The most potent isolate, identified as Stutzerimonas stutzeri PS1 using 16S rRNA sequencing. Growth dynamics were monitored through growth curve analysis, revealing a maximum biomass of 8.87±0.02 g/L and peak biosurfactant yield of 4.66 ± 0.57 g/L. Under these conditions, the Stutzerimonas stutzeri PS1 demonstrated significant surface activity, reducing surface tension to 43.33 ± 0.57 mN/m with an emulsification index (E24) of 47.43 ± 2.22 %. Systemic optimization of nutritional parameters identified glycerol and urea as the ideal carbon and nitrogen sources, respectively. The peak production was achieved at a physiological pH of 7 and an incubation temperature of 37°C. These findings highlight Stutzerimonas stutzeri PS1 as a significant and efficient candidate for scalable, sustainable production of biosurfactant for biotechnological and biomedical applications.