In the era of global industrialisation, the exploration of natural resources has served as a sour... more In the era of global industrialisation, the exploration of natural resources has served as a source of experimentation for science and advanced technologies, giving rise to the manufacturing of products with high aggregate value in the world market, such as biosurfactants. Biosurfactants are amphiphilic microbial molecules with hydrophilic and hydrophobic moieties that partition at liquid/liquid, liquid/gas or liquid/solid interfaces. Such characteristics allow these biomolecules to play a key role in emulsification, foam formation, detergency and dispersal, which are desirable qualities in different industries. Biosurfactant production is considered one of the key technologies for development in the 21st century. Besides exerting a strong positive impact on the main global problems, biosurfactant production has considerable importance to the implantation of sustainable industrial processes, such as the use of renewable resources and " green " products. Biodegradability and low toxicity have led to the intensification of scientific studies on a wide range of industrial applications for biosurfactants in the field of bioremediation as well as the petroleum, food processing, health, chemical, agricultural and cosmetic industries. In this paper, we offer an extensive review regarding knowledge accumulated over the years and advances achieved in the incorporation of biomolecules in different industries.
Biosurfactants are natural products derived from bacteria, yeasts or fungi. The complex chemical ... more Biosurfactants are natural products derived from bacteria, yeasts or fungi. The complex chemical structures and physical properties of biosurfactants generally result in properties equal to or exceeding many synthetic surfactants. Biosurfactants demonstrate low toxicity to freshwater, marine and terrestrial ecosystems and are potential candidates for a variety of environmental applications. Research has largely been focused on the enhancement of oil biodegradation and microbial-enhanced oil recovery. The solubilisation and emulsification of toxic heavy metals by biosurfactants have also been reported, assisting in the recovery of such hazardous materials from contaminated sites. The future success of biosurfactant technology in bioremediation initiatives is promising, but will require the precise targeting of the biosurfactant systems to reduce production costs and increase product yield. The suitability to the physical conditions and chemical nature of the pollution-affected site is also important the commercialisation of these biomolecules.
This work describes the application of microbial surfactants in the removal of petroleum and a de... more This work describes the application of microbial surfactants in the removal of petroleum and a derivative from marine environment. Two biosurfactants were produced by the yeasts Candida sphaerica and C. lipolytica cultivated in industrial residues as substrates during 144 h and 72 h, respectively. The surface tensions of the biomolecules were measured (25 mN/m), the production yields were calculated (8-9 g/L) and the Critical Micelle Concentrations (CMC) determined (0.03 %). Both biosurfactants were applied in samples of sea water and coral reefs artificially contaminated with petroleum and motor oil. The results showed a dispersant action of the biosurfactant from C. sphaerica while the biosurfactant from C. lipolytica showed a great oil emulsification capacity. Petroleum and motor oil percentages removal of 100 % were obtained. The possibility of application of these biosurfactants in the remediation of environments contaminated by hydrophobic hydrocarbons motivates the developmen...
Many biosurfactants have been produced, although few are produced due to the high costs of produc... more Many biosurfactants have been produced, although few are produced due to the high costs of production and purification processes. Given the potential for biotechnological application of these compounds in the oil and pharmaceutical industries, the optimization of the use of two industrial wastes, corn steep liquor and ground-nut oil refinery residue e as low cost nutrients for the production of a biosurfactant by Candida sphaerica (UCP 0995) was studied. Then the properties of the biosurfactant was described, and its isolation, preliminary chemical characterization. In this paper we used an optimized medium with distilled water supplemented with 9 % ground nut oil refinery residue and 9 % corn steep liquor as substrates to produce biosurfactants by Candida sphaerica, at 28 degrees C during 144h under 200rpm. The isolated biosurfactant was formed with a yield of 9g/L. The biosurfactant showed high surface tension reducing activity the 25 mN/m, a small CMC value (0.025 %), thermal (5-...
ABSTRACT Effects of PEG molecular weight, system polymer concentrations (tie-line lengths), pH an... more ABSTRACT Effects of PEG molecular weight, system polymer concentrations (tie-line lengths), pH and sodium chloride concentration, on the partition coefficient of trypsin in PEG-purified Anacardium occidentale L. (cashew tree) exudate gum polysaccharide aqueous two-phase systems have been investigated. Changes in PEG molecular weight, tie-line length and pH, had relatively little effect on trypsin partitioning, with partition coefficients (Κ) < 0.3, i.e., trypsin partitioned preferentially into the A. occidentale L. gum (lower) phase. However, addition of sodium chloride (0.1 M) resulted in dramatic increases in Κ values with increasing pH using the PEG 4000 (9% w/w)-purified A. occidentale L. gum (18% w/w) system, increasing to 3.70 at pH 7.0 and 9.77 at pH 8.0, i.e., trypsin partitioned preferentially into the PEG 4000 (upper) phase. Relative trypsin activities in the phases were investigated for these systems (with different sodium chloride levels) and high activities were obtained at pH 7.0 (70.9%) and pH 8.0 (90.9%) in 0.1 M sodium chloride, which in conjunction with their Κ values, clearly demonstrates their suitability as lower cost enzyme purification procedures (compared with PEG-dextran).
Statistical experimental designs and response surface methodology were employed to optimize the c... more Statistical experimental designs and response surface methodology were employed to optimize the concentrations of agroindustrial residues as soybean oil (SORR) from refinery, and corn steep liquor (CSL) from corn industry, for tensio-active agent produced by Candida sphaerica UCP 0995. Three 2 2 full factorial design were applied sequentially to investigate the effects of the concentrations and interactions of soybean oil refinery residue and corn steep liquor on the surface tension of free-cell culture broth for 144 h. Two 2 2 central composite designs and response surface methodology were adopted to derive a statistical model to measure the effect of SORR and CSL on the surface tension of the free-cell culture broth for 144 h. The regression equation obtained from the experimental data using a central composite design was solved, and by analyzing the response surface contour plots, the optimal concentrations of the constituents of the OPEN ACCESS Int. J. Mol. Sci. 2011, 12 2464 medium were determined: 8.63% v/v (9% v/v) of SORR and 8.80% v/v (9% v/v) CSL. The minimum surface tension predicted and experimentally confirmed was 25.25 mN/m. The new biosurfactant, denominated Lunasan, recovered 95% of motor oil adsorbed in a sand sample, thus showing great potential for use in bioremediation processes, especially in the petroleum industry.
The characterisation of bovine serum albumin (BSA) mass transfer mechanisms in a perforated rotat... more The characterisation of bovine serum albumin (BSA) mass transfer mechanisms in a perforated rotating disc contactor (PRDC) using an aqueous two-phase system (ATPS) composed of poly(ethylene glycol) (PEG) and a polysaccharide, the cashew-nut tree gum, was described. The PEG-rich phase was used as the dispersed phase and protein transfer took place from the dispersed to the continuous phase. Studies of
Journal of Chromatography B: Biomedical Sciences and Applications, 2000
The characterisation of a new system based on cashew-nut tree gum, a branched acidic heteropolysa... more The characterisation of a new system based on cashew-nut tree gum, a branched acidic heteropolysaccharide found in Brazil, and poly(ethylene glycol) (PEG) was studied. Phase diagrams are provided for the PEG–cashew-nut tree gum system. The influence of PEG molecular mass, tie-line length and pH on bovine serum albumin (BSA) partition was investigated. Protein partition coefficient was little influenced by changing PEG molecular mass. Increasing the tie-line length decreased the partition. Increasing the pH also raised the BSA partition coefficient. It is shown that systems formed by PEG and cashew-nut tree gum may be considered as an interesting alternative for use in protein purification.
Soil that is accidentally contaminated with petroleum hydrocarbons can be remediated by physical,... more Soil that is accidentally contaminated with petroleum hydrocarbons can be remediated by physical, chemical, or biological methods. However, new trends in soil and water restoration avoid introducing synthetic chemicals. Among the remediation techniques available for contaminated sites, bioremediation is regarded as environmentally friendly because it preserves the soil structure, requires little energy input, and involves the complete destruction or immobilization of the contaminants, although the efficiency of biodegradation of oil pollutants is often limited by their poor water solubility. Despite their advantages, due to the high production costs biosurfactants are not extensively used. In this sense the lipopeptide biosurfactant produced by Candida lipolytica (UCP 0988), is an attractive alternative to the synthetic surfactants, showing properties in bioremediation of heavy metals. The biosurfactant reduced the surface tension of the production medium from 50 mN/m to 25 mN/m, with a yield of 8 g/L, after 72 h of fermentation. The biosurfactant showed a CMC of 0.03 %. The lipoprotein removed 96 % of Zn and Cu, and reduced the concentration of Pb, Cd and Fe. The optimization process of biosurfactant production, which permitted the reduction of costs, suggests its ample utilization according to commercial requirements.
The influence of medium constituents on the production of biosurfactants by Candida tropicalis cu... more The influence of medium constituents on the production of biosurfactants by Candida tropicalis cultivated in waste frying oil was investigated according to a fractional factorial 2(5-1) design. The combined effect of the C/N(inorganic), C/Fe, C/Mg, and C/P ratios and yeast extract on surface tension reduction, biosurfactant yield, emulsification activity, and biomass were studied. The highest biosurfactant yield was reached when low C/Mg and low C/P ratio variables were combined, while the cell growth was favored by increasing the nitrogen concentration. The highest surface tension net decrease, on the other hand, was observed at low yeast extract concentration, low C/Fe, and high C/P ratios. Emulsification indices against lubrication and automobile waste oil of approximately 65 to 95% were observed. The crude biosurfactant produced in the medium--formulated with 2% waste frying oil, 0.067% NH4Cl, 0.025% MgSO4.7H2O, 0.067% KH2PO4, and 0.0026% FeCl3.6H2O--removed approximately 78 to 97% of the petroleum and motor oil adsorbed in sand samples.
The partition behaviour of trypsin in poly(ethylene glycol) (PEG) Á/cashew-nut tree gum aqueous t... more The partition behaviour of trypsin in poly(ethylene glycol) (PEG) Á/cashew-nut tree gum aqueous two-phase systems has been characterized. The enzyme partitioned preferentially into the cashew-nut tree gum phase. Investigation on the effect of the molecular weight of the PEG, the pH of system and the tie-line length of the biphasic diagram lead to the conclusion that the system properties had little effect on trypsin partition coefficients. In some cases, the NaCl addition changed dramatically the partition coefficient, this means that altering the conditions allows the manipulation of the protein partition. Maximum recovery of trypsin activity in the cashew-nut tree gum phase was obtained with PEG (molecular weight 8000) at pH 7.0 and 1.0 M NaCl. #
In the era of global industrialisation, the exploration of natural resources has served as a sour... more In the era of global industrialisation, the exploration of natural resources has served as a source of experimentation for science and advanced technologies, giving rise to the manufacturing of products with high aggregate value in the world market, such as biosurfactants. Biosurfactants are amphiphilic microbial molecules with hydrophilic and hydrophobic moieties that partition at liquid/liquid, liquid/gas or liquid/solid interfaces. Such characteristics allow these biomolecules to play a key role in emulsification, foam formation, detergency and dispersal, which are desirable qualities in different industries. Biosurfactant production is considered one of the key technologies for development in the 21st century. Besides exerting a strong positive impact on the main global problems, biosurfactant production has considerable importance to the implantation of sustainable industrial processes, such as the use of renewable resources and " green " products. Biodegradability and low toxicity have led to the intensification of scientific studies on a wide range of industrial applications for biosurfactants in the field of bioremediation as well as the petroleum, food processing, health, chemical, agricultural and cosmetic industries. In this paper, we offer an extensive review regarding knowledge accumulated over the years and advances achieved in the incorporation of biomolecules in different industries.
Biosurfactants are natural products derived from bacteria, yeasts or fungi. The complex chemical ... more Biosurfactants are natural products derived from bacteria, yeasts or fungi. The complex chemical structures and physical properties of biosurfactants generally result in properties equal to or exceeding many synthetic surfactants. Biosurfactants demonstrate low toxicity to freshwater, marine and terrestrial ecosystems and are potential candidates for a variety of environmental applications. Research has largely been focused on the enhancement of oil biodegradation and microbial-enhanced oil recovery. The solubilisation and emulsification of toxic heavy metals by biosurfactants have also been reported, assisting in the recovery of such hazardous materials from contaminated sites. The future success of biosurfactant technology in bioremediation initiatives is promising, but will require the precise targeting of the biosurfactant systems to reduce production costs and increase product yield. The suitability to the physical conditions and chemical nature of the pollution-affected site is also important the commercialisation of these biomolecules.
This work describes the application of microbial surfactants in the removal of petroleum and a de... more This work describes the application of microbial surfactants in the removal of petroleum and a derivative from marine environment. Two biosurfactants were produced by the yeasts Candida sphaerica and C. lipolytica cultivated in industrial residues as substrates during 144 h and 72 h, respectively. The surface tensions of the biomolecules were measured (25 mN/m), the production yields were calculated (8-9 g/L) and the Critical Micelle Concentrations (CMC) determined (0.03 %). Both biosurfactants were applied in samples of sea water and coral reefs artificially contaminated with petroleum and motor oil. The results showed a dispersant action of the biosurfactant from C. sphaerica while the biosurfactant from C. lipolytica showed a great oil emulsification capacity. Petroleum and motor oil percentages removal of 100 % were obtained. The possibility of application of these biosurfactants in the remediation of environments contaminated by hydrophobic hydrocarbons motivates the developmen...
Many biosurfactants have been produced, although few are produced due to the high costs of produc... more Many biosurfactants have been produced, although few are produced due to the high costs of production and purification processes. Given the potential for biotechnological application of these compounds in the oil and pharmaceutical industries, the optimization of the use of two industrial wastes, corn steep liquor and ground-nut oil refinery residue e as low cost nutrients for the production of a biosurfactant by Candida sphaerica (UCP 0995) was studied. Then the properties of the biosurfactant was described, and its isolation, preliminary chemical characterization. In this paper we used an optimized medium with distilled water supplemented with 9 % ground nut oil refinery residue and 9 % corn steep liquor as substrates to produce biosurfactants by Candida sphaerica, at 28 degrees C during 144h under 200rpm. The isolated biosurfactant was formed with a yield of 9g/L. The biosurfactant showed high surface tension reducing activity the 25 mN/m, a small CMC value (0.025 %), thermal (5-...
ABSTRACT Effects of PEG molecular weight, system polymer concentrations (tie-line lengths), pH an... more ABSTRACT Effects of PEG molecular weight, system polymer concentrations (tie-line lengths), pH and sodium chloride concentration, on the partition coefficient of trypsin in PEG-purified Anacardium occidentale L. (cashew tree) exudate gum polysaccharide aqueous two-phase systems have been investigated. Changes in PEG molecular weight, tie-line length and pH, had relatively little effect on trypsin partitioning, with partition coefficients (Κ) < 0.3, i.e., trypsin partitioned preferentially into the A. occidentale L. gum (lower) phase. However, addition of sodium chloride (0.1 M) resulted in dramatic increases in Κ values with increasing pH using the PEG 4000 (9% w/w)-purified A. occidentale L. gum (18% w/w) system, increasing to 3.70 at pH 7.0 and 9.77 at pH 8.0, i.e., trypsin partitioned preferentially into the PEG 4000 (upper) phase. Relative trypsin activities in the phases were investigated for these systems (with different sodium chloride levels) and high activities were obtained at pH 7.0 (70.9%) and pH 8.0 (90.9%) in 0.1 M sodium chloride, which in conjunction with their Κ values, clearly demonstrates their suitability as lower cost enzyme purification procedures (compared with PEG-dextran).
Statistical experimental designs and response surface methodology were employed to optimize the c... more Statistical experimental designs and response surface methodology were employed to optimize the concentrations of agroindustrial residues as soybean oil (SORR) from refinery, and corn steep liquor (CSL) from corn industry, for tensio-active agent produced by Candida sphaerica UCP 0995. Three 2 2 full factorial design were applied sequentially to investigate the effects of the concentrations and interactions of soybean oil refinery residue and corn steep liquor on the surface tension of free-cell culture broth for 144 h. Two 2 2 central composite designs and response surface methodology were adopted to derive a statistical model to measure the effect of SORR and CSL on the surface tension of the free-cell culture broth for 144 h. The regression equation obtained from the experimental data using a central composite design was solved, and by analyzing the response surface contour plots, the optimal concentrations of the constituents of the OPEN ACCESS Int. J. Mol. Sci. 2011, 12 2464 medium were determined: 8.63% v/v (9% v/v) of SORR and 8.80% v/v (9% v/v) CSL. The minimum surface tension predicted and experimentally confirmed was 25.25 mN/m. The new biosurfactant, denominated Lunasan, recovered 95% of motor oil adsorbed in a sand sample, thus showing great potential for use in bioremediation processes, especially in the petroleum industry.
The characterisation of bovine serum albumin (BSA) mass transfer mechanisms in a perforated rotat... more The characterisation of bovine serum albumin (BSA) mass transfer mechanisms in a perforated rotating disc contactor (PRDC) using an aqueous two-phase system (ATPS) composed of poly(ethylene glycol) (PEG) and a polysaccharide, the cashew-nut tree gum, was described. The PEG-rich phase was used as the dispersed phase and protein transfer took place from the dispersed to the continuous phase. Studies of
Journal of Chromatography B: Biomedical Sciences and Applications, 2000
The characterisation of a new system based on cashew-nut tree gum, a branched acidic heteropolysa... more The characterisation of a new system based on cashew-nut tree gum, a branched acidic heteropolysaccharide found in Brazil, and poly(ethylene glycol) (PEG) was studied. Phase diagrams are provided for the PEG–cashew-nut tree gum system. The influence of PEG molecular mass, tie-line length and pH on bovine serum albumin (BSA) partition was investigated. Protein partition coefficient was little influenced by changing PEG molecular mass. Increasing the tie-line length decreased the partition. Increasing the pH also raised the BSA partition coefficient. It is shown that systems formed by PEG and cashew-nut tree gum may be considered as an interesting alternative for use in protein purification.
Soil that is accidentally contaminated with petroleum hydrocarbons can be remediated by physical,... more Soil that is accidentally contaminated with petroleum hydrocarbons can be remediated by physical, chemical, or biological methods. However, new trends in soil and water restoration avoid introducing synthetic chemicals. Among the remediation techniques available for contaminated sites, bioremediation is regarded as environmentally friendly because it preserves the soil structure, requires little energy input, and involves the complete destruction or immobilization of the contaminants, although the efficiency of biodegradation of oil pollutants is often limited by their poor water solubility. Despite their advantages, due to the high production costs biosurfactants are not extensively used. In this sense the lipopeptide biosurfactant produced by Candida lipolytica (UCP 0988), is an attractive alternative to the synthetic surfactants, showing properties in bioremediation of heavy metals. The biosurfactant reduced the surface tension of the production medium from 50 mN/m to 25 mN/m, with a yield of 8 g/L, after 72 h of fermentation. The biosurfactant showed a CMC of 0.03 %. The lipoprotein removed 96 % of Zn and Cu, and reduced the concentration of Pb, Cd and Fe. The optimization process of biosurfactant production, which permitted the reduction of costs, suggests its ample utilization according to commercial requirements.
The influence of medium constituents on the production of biosurfactants by Candida tropicalis cu... more The influence of medium constituents on the production of biosurfactants by Candida tropicalis cultivated in waste frying oil was investigated according to a fractional factorial 2(5-1) design. The combined effect of the C/N(inorganic), C/Fe, C/Mg, and C/P ratios and yeast extract on surface tension reduction, biosurfactant yield, emulsification activity, and biomass were studied. The highest biosurfactant yield was reached when low C/Mg and low C/P ratio variables were combined, while the cell growth was favored by increasing the nitrogen concentration. The highest surface tension net decrease, on the other hand, was observed at low yeast extract concentration, low C/Fe, and high C/P ratios. Emulsification indices against lubrication and automobile waste oil of approximately 65 to 95% were observed. The crude biosurfactant produced in the medium--formulated with 2% waste frying oil, 0.067% NH4Cl, 0.025% MgSO4.7H2O, 0.067% KH2PO4, and 0.0026% FeCl3.6H2O--removed approximately 78 to 97% of the petroleum and motor oil adsorbed in sand samples.
The partition behaviour of trypsin in poly(ethylene glycol) (PEG) Á/cashew-nut tree gum aqueous t... more The partition behaviour of trypsin in poly(ethylene glycol) (PEG) Á/cashew-nut tree gum aqueous two-phase systems has been characterized. The enzyme partitioned preferentially into the cashew-nut tree gum phase. Investigation on the effect of the molecular weight of the PEG, the pH of system and the tie-line length of the biphasic diagram lead to the conclusion that the system properties had little effect on trypsin partition coefficients. In some cases, the NaCl addition changed dramatically the partition coefficient, this means that altering the conditions allows the manipulation of the protein partition. Maximum recovery of trypsin activity in the cashew-nut tree gum phase was obtained with PEG (molecular weight 8000) at pH 7.0 and 1.0 M NaCl. #
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