Microbial assisted ( pseudomonas sp.) production of novel bio-surfactant rhamnolipids and its characterisation by different spectral studies
- Citation data:
Journal of Molecular Liquids, ISSN: 0167-7322, Vol: 242, Page: 873-878
- Publication Year:
- Materials Science; Physics and Astronomy; Chemistry
The production and characterisation of rhamnolipids bio-surfactant obtained by the strain P19 of pseudomonas sp. was investigated. With regard to the carbon and nitrogen sources, several media were investigated to enhance the production of the bio-surfactant. Primarily the bacteria was isolated from the soil by using mineral salt (MS) broth [Peptone – 0.5 g, KH 2 PO 4 – 0.7 g, NaH 2 PO 4 – 0.9 g, NaNO 3 – 2 g, MgSO 4 ·7H 2 O – 0.4 g, CaCl 2 ·2H 2 O – 0.1 g]; trace elements: 2 mL solution of a mixture containing FeSO 4.7H 2 O – 2 g, MnSO 4 – 1.5 g, (NH 4 ) 6 Mo 7 ·4H 2 O – 0.6 g in 1 L of distilled water; along with 2 g/L d -glucose as carbohydrate source. The production of rhamnolipids by the bacteria was confirmed by C-TAB-methylene blue agar plate assay. The selected strain was identified on the basis of Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) of the ribosomal protein. The isolated bio-surfactant was characterised by HRMS and NMR spectroscopic studies. The CMC of purified rhamnolipids was calculated using the UV–Vis method and found to be 34.2 mg L −1. The optical micrograph and HR-TEM images invoked the formation of miceller nano-aggregates of the bio-surfactant in aqueous solution.