Combined effects of pH and biosurfactant addition on solubilization and biodegradation of phenanthrene

Shin, Kyoung-Hee; Kim, K.-W.; Seagren, Eric A.

doi:10.1007/s00253-004-1561-2

Cited by 43 publications

(51 citation statements)

References 35 publications

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“…The eVect of pH on surface activity has been reported for biosurfactants produced by various microorganisms [2]. Extreme pH values could possibly transform weak surfaceactive species into more active emulsiWers by increasing ionization, in agreement with the available literature [16,21,22,24]. The activity of the rhamnolipid produced by Rhodococcus [2] and surfactin produced by Bacillus subtillis [13] was also pH-stable in a wide range from 4 to 11.…”

Section: Biosurfactant Separation and Characterizationsupporting

confidence: 73%

Biosurfactant production by free and alginate entrapped cells of Pseudomonas fluorescens

Abouseoud

Yataghene

Amrane

et al. 2008

J Ind Microbiol Biotechnol

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Production of biosurfactant by free and alginate-entrapped cells of Pseudomonas fluorescens Migula 1895-DSMZ was investigated using olive oil as the sole carbon and energy source. Biosurfactant synthesis was followed by measuring surface tension and emulsifying index E24 over 5 days at ambient temperature and at neutral pH. Diffusional limitations in alginate beads affected the kinetics of biosurfactant production when compared to that obtained with free cells culture. Nevertheless, the emulsion stability was improved and fewer by-products interfered with the biosurfactant activity. A decrease in pH down to 5 in the case of immobilized cells was observed during the first 3 days, after which it returned to its initial value. The minimum values of surface tension were 30 and 35 dynes cm(-1) achieved after 40 and 72 h with free and immobilized cells, respectively, while the corresponding maximum E24 values were 67 and 62%, respectively. After separation by acetone precipitation, the biosurfactant showed a rhamnolipid-type in nature, and had a good foaming and emulsifying activities. The critical micellar concentration was found to be 290 mg l(-1). The biosurfactant also showed good stability during exposure to high temperatures (up to 120 degrees C for 15 min), to high salinity (10% NaCl) and to a wide range of pH (4-9).

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Section: Biosurfactant Separation and Characterizationsupporting

confidence: 73%

Biosurfactant production by free and alginate entrapped cells of Pseudomonas fluorescens

Abouseoud

Yataghene

Amrane

et al. 2008

J Ind Microbiol Biotechnol

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“…Due to the environmental friendly nature of the biosurfactants, many researchers have studied solubilization of organic hydrocarbons in presence of biosurfactants for the application in remediation process [22,128,[189][190][191][192][193]. Most of the researchers have used rhamnolipid biosurfactant for their studies.…”

Section: Solubilization In Biosurfactantmentioning

confidence: 99%

Surfactant-enhanced remediation of organic contaminated soil and water

Paria

2008

Advances in Colloid and Interface Science

485

237

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“…Until now, the interfacial activity and the efficacy of recovering residual hydrocarbon have only been studied with individual biosurfactant compounds. These studies show that solubilization and biodegradation are the main mechanisms for oil removal by biosurfactants [2,9,14,37,44]. Only a few studies showed mobilization of entrapped hydrocarbons [6,12,13].…”

Section: Discussionmentioning

confidence: 99%

“…The biosurfactants produced under these conditions could certainly be used as the third component in the mixtures to increase the percentage of a certain fatty acid to achieve the appropriate fatty acid composition required for ultra low IFT values. Although rhamnolipid biosurfactants have been investigated for subsurface remediation, most of the studies have focused on hydrocarbon removal by solubilization (increase in the aqueous solubility of the hydrocarbon) [9,37,44] rather than mobilization (lowering IFT between aqueous and LNAPL phases to reduce the capillary pressure that traps the oil) [12]. Here, we found that the rhamnolipid biosurfactant had a low IFT against toluene (0.31 ± 0.01 mN/m) and was more hydrophilic than all of the lipopeptides studied.…”

Section: Discussionmentioning

confidence: 99%

“…This may have been due to the pH, ionic strength, and biosurfactant concentration used for biodegradation studies. It has been shown that optimal pH for hydrocarbon solubilization might not be optimal for microbial growth and hydrocarbon degradation [37]. In some studies, biosurfactant concentrations above the CMC inhibited degradation [32].…”

Section: Introductionmentioning

confidence: 99%

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Basis for formulating biosurfactant mixtures to achieve ultra low interfacial tension values against hydrocarbons

Youssef

Nguyên

Sabatini

et al. 2007

J Ind Microbiol Biotechnol

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Biosurfactants could potentially replace or be used in conjunction with synthetic surfactants to provide for more cost-effective subsurface remediation. The design of surfactant formulations that are effective in lowering interfacial tension (IFT), which is necessary to mobilize entrapped hydrocarbons, requires information about the surface-active agent (surfactant) and the targeted non-aqueous phase liquids (NAPL). We hypothesized that biosurfactant and synthetic surfactant mixtures can be formulated to provide the appropriate hydrophobic/hydrophilic conditions necessary to produce low IFT against NAPLs, and that such mixtures will produce synergism that make them more effective than individual biosurfactants or synthetic surfactants. Our work tested the interfacial activity of biosurfactants from individual strains and mixtures of biosurfactants from different strains with and without a synthetic surfactant. Multiple regression analysis showed that, for lipopeptide biosurfactants produced by various Bacillus species, the interfacial activity against toluene depended on the relative proportions of 3-OH-C14, C15, C16, and C18 in the fatty acid tail. As the fatty acid composition became more heterogeneous the system produced lower IFT against toluene. In mixtures of lipopeptide biosurfactants with the more hydrophilic, rhamnolipid biosurfactant, the IFT against toluene decreased as the percentage of the 3-OH C14 fatty acid increased in the lipopeptide. Mixtures of lipopeptide biosurfactants with the more hydrophobic synthetic surfactant, C12, C13-8PO SO4Na, were able to produce low IFT against hexane and decane. In general, we found that lipopeptide biosurfactants with a heterogeneous fatty acid composition or mixtures of lipopeptide and rhamnolipid biosurfactants lowered the IFT against hydrophilic NAPLs. Conversely, mixtures of lipopeptide biosurfactants with a more hydrophobic synthetic surfactant lowered the IFT against hydrophobic NAPLs.

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Combined effects of pH and biosurfactant addition on solubilization and biodegradation of phenanthrene

Cited by 43 publications

References 35 publications

Biosurfactant production by free and alginate entrapped cells of Pseudomonas fluorescens

Biosurfactant production by free and alginate entrapped cells of Pseudomonas fluorescens

Surfactant-enhanced remediation of organic contaminated soil and water

Basis for formulating biosurfactant mixtures to achieve ultra low interfacial tension values against hydrocarbons

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