Remediation of Iron Using Rhamnolipid-Surfactant Produced by Pseudomonas aeruginosa

Abstract

Pseudomonas aeruginosa was isolated from 20 years abandoned mine site of Itagunmodi Atakunmosa West, Ilesha, Nigeria. Atomic absorption Spectrophotometry (AAS) revealed Fe, Mn, Cr, Zn, Pb and Cr, while, Fe has the highest concentration range of 29-289 ppm in the analysed soil samples. Soil samples were enriched in R2b agar, serially diluted and pour plated. Four bacteria strains were isolated and identified using standard biochemical test. After routine biosurfactant screening by oil spreading and emulsification test, biosurfactant producing bacteria was confirmed as Pseudomonas aeruginosa. The partially purified biosurfactants were characterized with TLC and GC-MS analysis. The analyses indicated glycolipid biosurfactant specifically designated as Rhamnolipid-sa1 containing isopalmitic acid, hexadecanoic acid, methyl ester and hydroxylated fatty acid linked to decanoic acids. Iron removal potential of the extracted biosurfactant was studied and the result revealed that Rhamnolipid-sa1 effectively reduced iron (60.34%) and could be useful as alternative remediation tool for treatment of iron contaminated soil.

Sequential soil washing with mixed biosurfactants is suitable for simultaneous removal of multi-metals from soils with different properties, pollution levels and ages

“…These decreases in Pb content in the PL fraction are due to removal of Pb from iron oxides and the results suggest that RAM more effectively releases Pb from these oxides than plant biosurfactants. Akintunde et al (2015) confirmed that the Fe concentration in soil was decreased about 60% by RAM. Neilson et al (2003) found that, although RAM did not effectively remove Pb from heavily contaminated (3780-23,900 mg/kg) aged soils, they were more effective than carboxymethyl-beta-cyclodextrin for removing Pb bound to amorphous iron oxides.…”

Intraspecies Signaling between Common Variants of Pseudomonas aeruginosa Increases Production of Quorum-Sensing-Controlled Virulence Factors

“…This coordinate regulation may aid in iron acquisition as QS-controlled phenazines, such as pyocyanin, reduce poorly soluble Fe 3ϩ to Fe 2ϩ and facilitate its uptake via the Feo system (92). Additionally, rhamnolipids have been employed for iron remediation (93,94), which suggests that their surfactant activity may increase P. aeruginosa substrate iron uptake in part through hydroxy-alkylquinolone-dependent mechanisms (95).…”

Natural surfactant mediated bioremediation approaches for contaminated soil

“… 107 Rhamnolipid-sa1 alone was reported to be effective to reduce iron up to 60.34% from the contaminated soil. 108 Another plant extracted biosurfactant, saponin, was believed to be efficient for removing heavy metals (Cu, Zn, Cr, Pb, Ni, Mn) using a sequential sludge washing method through the proposed mechanism in Fig. 7 .…”