Effect of rhamnolipid biosurfactants on performance of coal and mineral flotation

Khoshdast, Hamid; Sam, Abbas; Vali, Hojatollah; Noghabi, Kambiz Akbari

doi:10.1016/j.ibiod.2011.10.003

Cited by 46 publications

(21 citation statements)

References 13 publications

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“…Basic values >pH 8.0 were found to have exercised a more unfavourable effect on surface tension, biosurfactant production, and dry cell weight comparative to acidic pH values. However, in a recent report more prominent STR potential was observed at alkaline pH values in P. aeruginosa MA01 which could be attributed to formation of lipid vesicles (Khoshdast et al, 2011). The tolerance of biosurfactants to NaCl has been earlier reported as being restricted to NaCl 5% (Illori et al, 2005) and 15% (Darvishi et al, 2011).…”

Section: Optimization Of the Production Mediamentioning

confidence: 83%

Rhamnolipid biosurfactant production by Pseudomonas aeruginosa strain KVD-HR42 isolated from oil contaminated mangrove sediments

Deepika¹,

Raghuram²,

Bramhachari³

2017

Afr. J. Microbiol. Res.

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Pseudomonas aeruginosa strain KVD-HR42 exhibiting growth and biosurfactant production with 1% molasses as the sole carbon source was isolated from oil contaminated mangrove sediments. Optimization of media conditions involving variations in carbon, nitrogen sources, amino acids, pH, temperature, and NaCl% were evaluated with the aim of increasing biosurfactant productivity and surface tension reduction (STR). The highest biosurfactant production of 4.83 g/L was obtained when cells were grown in mineral salts media (MSM) supplemented with 1% (w/v) molasses, NaNO 3 , and leucine 0.1% (w/v) at 35±2°C at 150 rpm after 48 h. The results obtained from kinetics study indicated that biosurfactant production, E 24 %, and rhamnose concentration were growth associated. However, maximum biosurfactant production occurred in the exponential growth phase and detected an increase in E 24 % and rhamnose concentration. The Fourier transform infrared (FTIR) spectra confirmed the rhamnolipid nature of the biosurfactant. Stability studies revealed the thermostable activity of biosurfactant (110°C for 15 min) and could also withstand wide pH and NaCl ranges. Maximum oil biodegradation of 68% was achieved with 1% waste lubricant oil (WLO). The biosurfactant emulsified various hydrocarbons with varied efficiencies. However maximum E 24 % and E 48 % activity was exhibited with n-hexadecane (69.5 and 40%). The results reveal the potential of strain KVD-HR42 biosurfactant for the bioremediation of petroleum hydrocarbons in mangrove sediments.

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Section: Optimization Of the Production Mediamentioning

confidence: 83%

Rhamnolipid biosurfactant production by Pseudomonas aeruginosa strain KVD-HR42 isolated from oil contaminated mangrove sediments

Deepika¹,

Raghuram²,

Bramhachari³

2017

Afr. J. Microbiol. Res.

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“…Rhamnolipids showed an almost stable surface activity profile at pH values less than neutral (from 7 to 2). A more pronounced reduction in surface activity was observed at alkaline pH values, which could be ascribed to the formation of vesicles at these pH values (Khoshdast et al, 2011).…”

Section: Effect Of Ph and Temperature On Surface Tensionmentioning

confidence: 87%

“…Furthermore, in a study conducted by Onbasli and Aslim (2009) the strains of P. aeruginosa examined produced rhamnolipids at 250-300 mg/L. Moreover, Khoshdast et al (2011) suggested that rhamnolipids produced from the strain P. aeruginosa Ma01 decreased the surface tension of the culture from 70 dyne/cm 2 to 30 dyne/cm 2 at the end of incubation.…”

Section: Determination Of Biosurfactant-producer Strainsmentioning

confidence: 98%

Production of biosurfactant by Pseudomonas spp. isolated from industrial waste in Turkey

Kaya¹,

Aslım²,

Kariptaş³

2014

Turk J Biol

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In this study, 26 Pseudomonas spp. were isolated from a stream polluted by factory waste and from petroleum-contaminated soil. The surface tension (ST) of the cultures was used as a criterion for the primary isolation of biosurfactant-producing bacteria. Biosurfactant production was quantified by ST reduction, critical micelle concentration (CMC), emulsification capacity (EC), and cell surface hydrophobicity (CSH). Two of the isolates, P. aeruginosa 78 and 99, produced rhamnolipid biosurfactant. The strains started rhamnolipid production in the logarithmic phase. They decreased the ST of the culture from 73 dyne/cm 2 to 29 and 33 dyne/cm 2 , and the CMC of produced rhamnolipids were 115 and 130 mg/L, respectively. P. aeruginosa 78 and 99 strains emulsified benzene and n-hexane at the highest rates, and the surfaces of these strains were 73% and 65% and 62% and 72% more hydrophobic for benzene and toluene, respectively.

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“…Depending on the number of rhamnose molecules, rhamnolipids are classified as either mono‐ or di‐ rhamnolipid. Rhamnolipids have widely been used in various fields (Fazaelipoor et al, 2010; Khoshdast et al, 2011; Ochoa‐Loza et al, 2007; Sandrin et al, 2000; Torrens et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

Rhamnolipid–Metal Ions (Cr^VI and Pb^II) Complexes: Spectrophotometric, Conductometric, and Surface Tension Measurement Studies

Hari

Upadhyay

2020

J Surfact & Detergents

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The formation of rhamnolipid complexes with metal ions of chromium (VI) and lead (II) has been studied spectrophotometrically, conductometrically, and by surface tension measurement. The values of the critical micelle concentration (CMC) of rhamnolipid, obtained by spectroscopic, conductometric, and surface tension measurements, were 5.2 × 105, 5.0 × 105, and 5.3 × 105 mol.dm−3, respectively, which are in close agreement. An increase in CMC on increasing metal ion content in the rhamnolipid solution and a shift in λmax in the spectra of rhamnolipid indicated the formation of a complex between rhamnolipid and both the metal ions, namely, chromium (VI) and lead (II). The values of stability constants for the {rhamnolipid–chromium (VI)} and {rhamnolipid–lead (II)} complexes have been determined by spectroscopic data and were as 0.58 × 104 and 0.50 × 104 at 308 K, respectively. The thermodynamic parameters for micellization, namely, free energy change (∆Gmic), entropy change (∆Smic), and heat enthalpy change (∆Hmic), have been determined by conductivity measurements. An increase in the negative value of ∆Gmic and a decrease in the value of ∆Smicon increasing metal ion content in the surfactant solution indicated lower micellization of rhamnolipid in the presence of metal ions. The electrostatic attractions and entrapment of chromium (VI) in the micelles of the biosurfactants were found to be responsible for {rhamnolipid–lead (II)} and {rhamnolipid–chromium (VI)} complexes, respectively.

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Effect of rhamnolipid biosurfactants on performance of coal and mineral flotation

Cited by 46 publications

References 13 publications

Rhamnolipid biosurfactant production by Pseudomonas aeruginosa strain KVD-HR42 isolated from oil contaminated mangrove sediments

Rhamnolipid biosurfactant production by Pseudomonas aeruginosa strain KVD-HR42 isolated from oil contaminated mangrove sediments

Production of biosurfactant by Pseudomonas spp. isolated from industrial waste in Turkey

Rhamnolipid–Metal Ions (Cr^VI and Pb^II) Complexes: Spectrophotometric, Conductometric, and Surface Tension Measurement Studies

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Effect of rhamnolipid biosurfactants on performance of coal and mineral flotation

Cited by 46 publications

References 13 publications

Rhamnolipid biosurfactant production by Pseudomonas aeruginosa strain KVD-HR42 isolated from oil contaminated mangrove sediments

Rhamnolipid biosurfactant production by Pseudomonas aeruginosa strain KVD-HR42 isolated from oil contaminated mangrove sediments

Production of biosurfactant by Pseudomonas spp. isolated from industrial waste in Turkey

Rhamnolipid–Metal Ions (CrVI and PbII) Complexes: Spectrophotometric, Conductometric, and Surface Tension Measurement Studies

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Rhamnolipid–Metal Ions (Cr^VI and Pb^II) Complexes: Spectrophotometric, Conductometric, and Surface Tension Measurement Studies