Production of an extracellular emulsifier by a gram negative bacterium

Palejwala, Smita; Desai, J. D.

doi:10.1007/bf01192185

Cited by 16 publications

(10 citation statements)

References 7 publications

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“…Heat treatment of some biosurfactants caused no appreciable change in surfactant properties such as the lowering of surface tension and interfacial tension (2). The biosurfactant produced by B. subtilis MTCC 2423 was thermostable and retained its surface activity even after heating at 100°C for 2 h. Similar results have been reported for the surfactin and lichenysin (9).…”

Section: Discussionsupporting

confidence: 72%

“…Haferberg et al (6) and Guerra-Santos et al (7) reported that the majority of known biosurfactants are synthesized by microorganisms grown on water-immiscible hydrocarbons, which are expensive and therefore increase the overall process cost. However, other cheaper, water-soluble substrates such as glucose, glycerol, and mannitol (8)(9)(10) have been used to produce biosurfactants. Until now biosurfactants have been unable to compete economically with chemically synthesized compounds in the market because of their high production costs, which are due to the inefficient bioprocessing methodologies available, poor strain improvement, and the need to use expensive substrates.…”

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confidence: 99%

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Effects of various nutritional supplements on biosurfactant production by a strain of Bacillus subtilis at 45°C

Makkar

Cameotra

2002

J Surfact & Detergents

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Effects of various factors on growth and biosurfactant production by Bacillus subtilis MTCC 2423 were studied. Sucrose (2%) and potassium nitrate (0.3%) were the best carbon and nitrogen sources. The addition of various metal supplements (magnesium, calcium, iron, and trace elements) greatly affected growth and biosurfactant production. The effect of the metal cations, used together, is greater than when they are used individually. The biosurfactant production increased considerably (almost double) by addition of metal supplements. Very high concentrations of metal supplements, however, inhibited biosurfactant production. Amino acids such as aspartic acid, asparagine, glutamic acid, valine, and lysine increased the final yield of biosurfactant by about 60%. The organism could produce biosurfactant at 45°C and within the pH range of 4.5-10.5. The biosurfactant was thermostable and pH stable (from 4.0 to 12.0). The capability of the organism to produce biosurfactant under thermophilic, alkaliphilic, and halophilic conditions makes it a suitable candidate for field applications. Infrared, nuclear magnetic resonance, and mass spectroscopy studies showed the surfactant to be identical to surfactin.

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Section: Discussionsupporting

confidence: 72%

mentioning

confidence: 99%

Effects of various nutritional supplements on biosurfactant production by a strain of Bacillus subtilis at 45°C

Makkar

Cameotra

2002

J Surfact & Detergents

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“…Haferberg et al (21) and Guerra Santos et al (22) reported that microorganisms grown on expensive water-immiscible hydrocarbons synthesize the majority of known biosurfactants synthesized, thus increasing the overall process cost. However, other cheaper water-soluble substrates such as glucose, glycerol, and ethanol have been used to produce biosurfactants (23)(24)(25). In this work, biosurfactant production by B. subtilis MTCC 2423 at thermophilic growth conditions was studied and characterized.…”

Section: Resultsmentioning

confidence: 99%

Structural characterization of a biosurfactant produced by Bacillus subtilis at 45°C

Makkar¹,

Cameotra²

1999

J Surfact & Detergents

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Structural and biochemical characterization of a biosurfactant produced by Bacillus subtilis under thermophilic conditions was performed. Preliminary structural determination of CHCl 3 /CH 3 OH (65:15) extracts by thin-layer chromatographic reagents showed it to be identical to surfactin. Also, the infrared, 1 H nuclear magnetic resonance, and mass spectroscopy analysis confirmed it to be identical to surfactin. Biochemically, the surfactant was a lipopeptide-containing lipid (17.05%) and protein (13.2%). The surfactant yielded a minimal aqueous surface-tension value of 28 dyne/cm and an interfacial tension value at 0.1% concentration of 0.2 dyne/cm against diesel oil. The critical micelle concentration of the surfactant was 35 mg/L. The biosurfactant exhibited an emulsification value (E 24 ) of 90 against diesel oil and a sand-pack oil recovery of 62%. It has potential application in microbial-enhanced oil recovery in thermophilic, alkaline, acidic, and halophilic environments. The culture was maintained on nutrient agar plates. Media and cultivation conditions. For biosurfactant synthesis, a mineral salt medium with the following composition was utilized: KNO 3 (0.3%), Na 2 HPO 4 (0.22%), KH 2 PO 4 (0.014%), NaCl (0.001%), MgSO 4 (0.06%), CaCl 2 (0.004%), FeSO 4 (0.002%), and 0.1 mL of trace element solution contain-FIG. 2. 1 H nuclear magnetic reasonance (NMR) spectrum of the biosurfactant produced by Bacillus subtilis MTCC 2423 at 45°C. TMS, tetramethylsilane; NHs, imide hydrogens of peptide bond; CαH 2 , alpha hydrogens; Hα s , alpha hydrogens. FIG. 3. Fast atom bombardment mass spectrum of the biosurfactant produced by Bacillus subtilis MTCC 2423 at 45°C.

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“…These properties are discussed in terms of emulsifying capacity (EC), emulsifying stability (ES) and emulsification activity (EA). The ES is commonly measured in terms of the time that an amount of oil and/or cream separating from an emulsion depending on temperature, gravitational field and the concentration of oil in the emulsion (Lima et al, 1997;Palejwala andDesai, 1989, Pearce andKinsela, 1978). The aim of this work was to study the influence of pH, temperature and biosurfactants type on emulsifier stability from diesel oil in water and the biosurfactant by Saccharomyces lipolytica CCT-0913 on emulsifier stability from vegetable oil and mineral oil in water.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of emulsifier stability of biosurfactant produced by Saccharomyces lipolytica CCT-0913

Lima

Alegre

2009

Braz. arch. biol. technol.

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Surface-active compounds of biological origin are widely used for many industries (cosmetic, food, petrochemical). The Saccharomyces lipolytica CCT-0913 was able to grow and produce a biosurfactant on 5% (v/v) diesel-oil at pH 5.0 and 32 o C. The cell-free broth emulsified and stabilized the oil-in-water emulsion through a first order kinetics. The results showed that the initial pH value and temperature influenced the emulsifier stability (ES), which was the time when oil was separated. The biosurfactant presented different stabilization properties for vegetable and mineral oil in water solution, despite the highest values of the ES occurring with vegetable oil. The biosurfactantpresented smallest ES when compared to commercial surfactants; however, this biosurfactant was not purified.

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Production of an extracellular emulsifier by a gram negative bacterium

Cited by 16 publications

References 7 publications

Effects of various nutritional supplements on biosurfactant production by a strain of Bacillus subtilis at 45°C

Effects of various nutritional supplements on biosurfactant production by a strain of Bacillus subtilis at 45°C

Structural characterization of a biosurfactant produced by Bacillus subtilis at 45°C

Evaluation of emulsifier stability of biosurfactant produced by Saccharomyces lipolytica CCT-0913

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