Utilization of Agro-Industry Residue for Rhamnolipid Production by P. aeruginosa AMB AS7 and Its Application in Chromium Removal.
Coconut oil sludge and oil cake was utilized as carbon source for biosurfactant production by Pseudomonas aeruginosa AMB AS7. The results of optimization study revealed that 1.5% (w/v) of coconut oil cake, 2% (w/v) of coconut oil sludge, pH 7.2, 37 °C, and 120 rpm were the optimum conditions for biosurfactant production. The yield coefficient of biosurfactant on biomass (YP/X) was 1.29 g/g. Besides, the results indicated that aeration of 0.5 vvm and agitation of 450 rpm in bioreactor resulted in high volumetric productivity of biosurfactant (rp) and specific product formation rate (qp) of 0.115 g/(L h) and 0.0131 g/(g h), respectively in medium containing 2% (w/v) coconut oil sludge. The maximum biosurfactant concentration of 5.53 g/L was obtained during 60 h of cultivation. The emulsification index (EI24) against coconut oil was found to be 88.42 ± 0.5%, and cell surface hydrophobicity of P. aeruginosa AMB AS7 was obtained 32.4 ± 0.9%. FTIR and GC-MS analysis revealed that the biosurfactant is rhamnolipid with anionic charge. The critical micelle concentration (CMC) of rhamnolipid was found to be 50 mg/L. It was found that 66.95% of chromium from aqueous solution can be removed using rhamnolipid at its CMC.
Department of Biotechnology, Kamaraj College of Engineering and Technology, S.P.G.C. Nagar, Virudhunagar, Tamilnadu, 626001, India.
Mariaamalraj
M
Samykannu
Department of Biotechnology, Kamaraj College of Engineering and Technology, S.P.G.C. Nagar, Virudhunagar, Tamilnadu, 626001, India. achyanant@yahoo.com.
Anant
A
Achary
D001673:Biodegradation, Environmental; D002857:Chromium / Q000378:metabolism*; D006017:Glycolipids / Q000096:biosynthesis* / Q000302:isolation & purification*; D011550:Pseudomonas aeruginosa / Q000254:growth & development*
D006017:Glycolipids; C418382:rhamnolipid; D002857:Chromium
Bioreactor study; Cell surface hydrophobicity; Chromium removal; Coconut oil sludge and cake; Rhamnolipid