Production optimization, purification and characterization of lipopeptide biosurfactant obtained from Brevibacillus sp. AVN13

• Published in: Journal of environmental chemical engineering Vol. 9; no. 1; p. 104867
• Main Authors: Vigneshwaran, C., Vasantharaj, K., Krishnanand, N., Sivasubramanian, V.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2021
• Subjects: Biosurfactants; Brevibacillus; FPLC; Lipopeptide; NMR; FPLC; Brevibacillus; NMR; Biosurfactants; Lipopeptide
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2020.104867

The present study reports on production of biosurfactant (surface active compound) by a novel bacterial strain Brevibacillus sp. AVN 13 isolated from the crude oil contaminated soil. The purification and characterization of the biosurfactant were also investigated. Optimization studies using Box−Behnken design and response surface methodology were performed in order to define the best inocula conditions favoring maximum biosurfactant yield. The optimized medium conditions for maximum yield were found to be pH (7.1), temperature (38 °C), used engine oil (0.90 v/v%) and potassium nitrate (0.53 w/v%). Utilizing the predicted optimized conditions, the maximal biosurfactant yield of 1.29 g/L was achieved which agreed well with the predicted value. The crude biosurfactant was purified by ammonium sulfate precipitation and solvent extraction followed by Fast Protein Liquid Chromatography (FPLC). Thin layer chromatography (TLC), Gas chromatography and mass spectrometry (GC−MS) and 1H and 13C Nuclear magnetic resonance spectroscopy (NMR) were used to characterize the purified biosurfactant. The molecular mass of the purified product was determined through Tricine SDS-PAGE and CMC of purified biosurfactant were also studied. Further the structural characterization studies revealed that the surface active compound contain lipopeptide compound. [Display omitted] •The new Brevibacillus sp. AVN 13 strain showed promising biosurfactant production.•Production using Box-Behnken design improved biosurfactant yield of 1.29 g/L.•The purified biosurfactant had relative molecular weight ≤ 2.5 kDa.•The purified biosurfactant exhibited low surface tension values.•TLC, GC−MS and 1H and 13C NMR studies revealed lipopeptide nature of biosurfactant.