Excellent Surface-active Properties Research Articles

A basidiomycetous yeast, Pseudozyma crassa, produces novel diastereomers of conventional mannosylerythritol lipids as glycolipid biosurfactants

Mannosylerythritol lipids (MELs) are glycolipid biosurfactants produced by the yeast strains of the genus Pseudozyma. These compounds show not only excellent surface-active properties, but also versatile biochemical actions. During a survey of new MEL producers, we found that a basidiomycetous yeast, Pseudozyma crassa, extracellularly produces three glycolipids. When glucose and oleic acid were used as the carbon source, the total amount of glycolipids reached approximately 4.6 g/L in the culture medium. The structures of these glycolipids were similar to those of well-known MEL-A, -B, and -C, respectively. Very interestingly, in all the present glycolipids, the configuration of the erythritol moiety was entirely opposite to that of conventional MELs. The present glycolipids were identified to have the carbohydrate structure of 4- O-β- d-mannopyranosyl-(2 R,3 S)-erythritol, stereochemically different from 4- O-β- d-mannopyranosyl-(2 S,3 R)-erythritol of conventional MELs. Furthermore, these new glycolipids possessed both short-chain acids (C 2 or C 4) and long-chain acids (C 14, C 16, or C 18) on the mannose moiety. The major component of the present glycolipids clearly showed different interfacial and biological properties, compared to conventional MELs comprising two medium-chain acids on the mannose moiety. Accordingly, the novel MEL diastereomers produced by P. crassa should provide us with different glycolipid functions, and facilitate a broad range of applications of MELs.

Surface treatment of CoFe 2O 4 nanoparticles to improve their dispersibility in aqueous phase with new fluorine-contain polymers

Magnetite CoFe 2O 4 nanoparticles were modified by a new series of fluorine-containing polymeric dispersants. The Fourier transform infrared spectroscopy (FTIR) and element analysis showed that the polymer chains have been successfully adsorbed onto the surfaces of the CoFe 2O 4 nanoparticles. The influence of the content of fluoroalkyl groups on the surface tension and the dispersing properties were also investigated and the results showed that the modified CoFe 2O 4 nanoparticles exhibit excellent surface active properties and the nanoparticles can be dispersed very well in the aqueous phase. Zeta potential and the average diameter of the nanoparticles can reach to −68 mV and 42 nm with the increasing of the content of fluoroalkyl groups of the polymeric dispersant, respectively.

Techbits: Naphthenate Deposits, Emulsions Highlighted in Technology Workshop

Techbits Pau, France was the scene for a recent SPE Applied Technology Workshop (ATW) titled "Managing Naphthenates and Soap Emulsions." From 10–13 March 2008, more than 70 attendees discussed the flow assurance challenges that naphthenate deposition presents, as well as the current state of the art in mitigating their formation in the field. Colin Smith, senior consultant with Maxoil Solutions and ATW Committee Member, opened the workshop with a scene-setting discussion on the fundamentals of naphthenate sludge and emulsion formation. If left unchecked, naphthenate deposits may cause fouling or plugging of production equipment such as flowlines and separators, and the formation of stable emulsions may prevent efficient oil/water separation, increasing separator residence times. The problem is more common than the industry might think, according to Smith; naphthenate deposits are present in 10% or more of North Sea crudes, while 30% of southeast Asian crudes and 20% of west African crudes demonstrate soap emulsion or sludge problems. Smith mentioned that naphthenates were first clearly identified in oilfields in the 1960s, but research and development (R&D) efforts began in earnest in the mid-1990s. The first session of the workshop highlighted the fundamentals. Johan Sjoblom, Professor at the Norwegian University of Science and Technology (NTNU), examined the current understanding of the different types of acids in a crude oil that can lead to naphthenate formation and sludge or emulsion problems. Monoacids (those acids with one carboxyl [COOH] group) tend to stabilize emulsions and concentrate in the oil phase or sludges, while tetracids (those with four COOH groups) can stabilize oil/water emulsions and tend to react with metallic ions such as calcium (Ca2+) to form deposits that harden irreversibly. Christian Hurtevent, an expert in physical chemistry and deposits with Total, discussed his company's experience with emulsion formation based on oil density and acid type. In general, Total has observed biodegradation and deposit problems in problem crudes with lower API values (<30), while higher API problem crudes tend to demonstrate emulsion stability challenges. The company has used an ultrasonic scanner to evaluate emulsion phase behavior, which has suggested how various naphthenic salts aggregate in a crude oil/water mixture. Ingemar Uneback, Application Development Manager for Akzo Nobel, proposed how derivatives of naphthenic mono acids could be extracted from crude oil and used as favorable starting blocks in chemical synthesis. In the formation of surfactants, for example, several monoacids demonstrate excellent surface active properties, low viscosity, good oxidative stability, and favorable biodegradability for environmentally sensitive applications. Uneback stated that Akzo Nobel has begun testing naphthenic monoacids as surfactants with promising results for potential application in fuels, agrochemicals, oilfield process chemicals, and asphalts.

A basidiomycetous yeast, Pseudozyma tsukubaensis, efficiently produces a novel glycolipid biosurfactant. The identification of a new diastereomer of mannosylerythritol lipid-B

Mannosylerythritol lipids (MELs) are glycolipid biosurfactants produced by the yeast strains of the genus Pseudozyma. These compounds show not only excellent surface-active properties but also versatile biochemical activities. In the course of MEL production by Pseudozyma tsukubaensis, we found an unusual MEL that had a different carbohydrate structure from that of conventional MELs. The carbohydrate structure was identified as 1- O-β- d-mannopyranosyl- d-erythritol, and the MEL was confirmed to be 1- O-β-(2′,3′-di- O-alka(e)noyl-6′- O-acetyl- d-mannopyranosyl)- d-erythritol. Interestingly, the configuration of the erythritol moiety in the present MEL was opposite to that of the known MEL-B, 4- O-β-(2′,3′-di- O-alka(e)noyl-6′- O-acetyl- d-mannopyranosyl)- d-erythritol, and to that of all MELs hitherto reported. The present MEL should thus provide different interfacial and biochemical properties compared to conventional MELs.

A yeast glycolipid biosurfactant, mannosylerythritol lipid, shows high binding affinity towards lectins on a self-assembled monolayer system

Mannosylerythritol lipids (MEL), which are glycolipid biosurfactants secreted by the Pseudozyma yeasts, show not only excellent surface-active properties but also versatile biochemical actions including antitumor and cell-differentiation activities. In order to address the biochemical actions, interactions between MEL-A, the major component of MEL, and different lectins were investigated using the surface plasmon resonance spectroscopy. The monolayer of MEL-A showed high binding affinity to concanavalin A (ConA) and Maackia amurensis lectin-I (MAL-I). The observed affinity constants for ConA and MAL-I were estimated to be 9.48 +/- 1.31 x 10(6) and 3.13 +/- 0.274 x 10(6) M(-1), respectively; the value was comparable to that of Manalpha1-6(Manalpha1-3)Man, which is one of the most specific probe to ConA. Significantly, alpha-methyl-D-mannopyranoside (1 mM) exhibited no binding inhibition between MEL-A and ConA. MEL-A is thus likely to self-assemble to give a high affinity surface, where ConA binds to the hydrophilic headgroup in a different manner from that generally observed in lectin-saccharide interactions. The binding manner should be related with the biochemical actions of MEL toward mammalian cells via protein-carbohydrate interactions.

Characterization of New Types of Mannosylerythritol Lipids as Biosurfactants Produced from Soybean Oil by a Basidiomycetous Yeast, Pseudozyma shanxiensis

Mannosylerythritol lipids (MELs) are glycolipid biosurfactants produced by the yeast strains of the genus Pseudozyma. These show not only the excellent surface-active properties but also versatile biochemical actions. In course of MEL production from soybean oil by P. shanxiensis, new extracellular glycolipids (more hydrophilic than the previously reported MELs) were found in the culture medium. As a result of the structural characterization, the glycolipids were identified as a mixture of 4-O-[(2', 4'-di-O-acetyl-3'-O-alka(e)noyl)-beta-D-mannopyranosyl]-D-erythritol and 4-O-[(4'-O-acetyl-3'-O-alka(e)noyl-2'-O-butanoyl)-beta-D-mannopyranosyl]-D-erythritol. Interestingly, the new MELs possessed a much shorter chain (C(2) or C(4)) at the C-2' position of the mannose moiety compared to the MELs hitherto reported, which mainly possess a medium-chain acid (C(10)) at the position. They would thus show higher hydrophilicity and/or water-solubility, and expand the development of the environmentally advanced yeast biosurfactants.

Characterization of the genusPseudozymaby the formation of glycolipid biosurfactants, mannosylerythritol lipids

Pseudozyma antarctica is one of the best producers of the glycolipid biosurfactants known as mannosylerythritol lipids (MELs), which show not only excellent surface-active properties but also versatile biochemical actions. In order to obtain a variety of producers, all the species of the genus were examined for their production of MELs from soybean oil. Pseudozyma fusiformata, P. parantarctica and P. tsukubaensis were newly identified to be MEL producers. Of the strains tested, P. parantarctica gave the best yield of MELs (30 g L(-1)). The obtained yield corresponded to those of P. antarctica, P. aphidis and P. rugulosa, which are known high-level MEL producers. Interestingly, P. parantarctica and P. fusiformata produced mainly 4-O-[(4',6'-di-O-acetyl-2',3'-di-O-alkanoyl)-beta-d-mannopyranosyl]-meso-erythritol (MEL-A), whereas P. tsukubaensis produced mainly 4-O-[(6'-mono-O-acetyl-2',3'-di-O-alkanoyl)-beta-d-mannopyranosyl]-meso-erythritol (MEL-B). Consequently, six of the nine species clearly produced MELs. Based on the MEL production pattern, the nine species seemed to fall into four groups: the first group produces large amounts of MELs; the second produces both MELs and other biosurfactants; the third mainly produces MEL-B; and the fourth is non-MEL-producing. Thus, MEL production may be an important taxonomic index for the Pseudozyma yeasts.

Preparation and surface activity of modified soy protein

AbstractA series of novel surfactants have been prepared by the reaction of hydrolyzed soy protein with alkyl succinic anhydride. These novel surfactants exhibit excellent surface active properties including surface tension, foaming, emulsifying, wetting power, and buffer ability. The hydrophobic modified protein exhibit more surface activity than original protein because of the enhanced hydrophobicity in structure. The increase in hydrophobic chain length leads to an increase in the surface activity. The surface tension reduction is correlated to the hydrophobicity of the modified molecule, which was determined by a fluorescent probe. In application on cotton bleaching procedures, these surfactants increase the whiteness of fabrics. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3498–3503, 2006

Preparation and properties of new tetrafunctional amphoteric surfactants bearing amino, carboxyl, and hydroxyl groups and an ether bond

New amphoteric surfactants of N-(3-alkoxy-2-hydroxypropyl)-N-(2-hydroxyethyl)-β-alanine (APA) have been synthesized. The fundamental surface-active properties (critical micelle concentration and isoelectric point) and hemolysis tests were also investigated to examine the effects of differences in chain length of the alkoxy moiety. The hemolysis result of APA exhibited low constant values irrespective of the alkyl chain length. The amphoteric APA surfactant was confirmed to have a mild effect on human microorganisms and to possess excellent surface-active properties. In addition, a speculative model of micelle configuration was estimated by semiempirical molecular orbital simulations.

Synthesis and surface activity of polyethylene glycol–maleic anhydride–polydimethylsiloxane polyester surfactants

Abstract A novel series of water-soluble polyethylene glycol (PEG)–silicone polyester surfactants has been prepared by the polymerization of PEG, maleic anhydride, polydimethylsiloxane and fumaric acid. The unique structural features of these surfactants have been confirmed by FTIR, proton nuclear magnetic resonance and elemental analysis. Also, the influences of the PEG segment lengths of PEG–silicone polyesters on the surface tension, wetting power and dispersant properties were investigated. The experimental results indicated that the solution that contained the PEG–silicone polyester surfactants exhibits excellent surface active properties.

Diospyros melanoxylon Leaves: A Rich Source of Pentacyclic Triterpenes

In a program designed to search for alternative uses of Diospyros melanoxylon leaves (bidi wrapper leaves), extensive chemical screening resulted in the isolation of nine pentacyclic triterpenes and ß -sitosterol. Out of the nine pentacyclic triterpenes, two are hitherto unreported (2 and 4), four are taxonomically significant (7-10), and the remaining three (1, 5 and 6) are known. Significantly, the ursane structures, viz., a -amyrin (0.7%) and ursolic acid (0.56%) and corsolic acid (0.14%), were obtained in fairly large quantities. In view of the excellent surface active properties and interesting biological activities attributed to some of these skeletons, their present isolation is of relevance.

Preparation of water‐soluble polyurethane surfactants

A novel series of water-soluble polyurethane surfactants has been prepared by the addition polymerization of 2,4 and 2,6-toluene diisocyanate 80 : 20%, respectively (TDI) to polyethylene glycol (PEG) and/or castor oil and ethylene glycol (EG). These water-soluble polyurethane surfactants have been found to exhibit excellent surface active properties including surface tension, foaming and wetting tendency, and formation of stable emulsions. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1531–1536, 1998

Preparation of water-soluble polyurethane surfactants

A novel series of water-soluble polyurethane surfactants has been prepared by the addition polymerization of 2,4 and 2,6-toluene diisocyanate 80 : 20%, respectively (TDI) to polyethylene glycol (PEG) and/or castor oil and ethylene glycol (EG). These water-soluble polyurethane surfactants have been found to exhibit excellent surface active properties including surface tension, foaming and wetting tendency, and formation of stable emulsions. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1531–1536, 1998

Synthesis of sucrose-based surfactants through regioselective sulfonation of acylsucrose and the nucleophilic opening of a sucrose cyclic sulfate

Synthesis of a new class of anionic and amphoteric sucrose-based surfactants is described. Direct sulfonation of 6- O-acylsucrose using the pyridine–sulfur trioxide complex led to a mixture of the regioisomeric monosulfates, 6- O-acyl-4′– O-sulfosucrose and 6- O-acyl-1′- O-sulfosucrose, while sulfonation of 1′- O-acylsucrose afforded a mixture of 1′- O-acyl-6′- O-sulfosucrose and 1′- O-acyl-6- O-sulfosucrose. The ratio of regioisomers ranged from 4.7:1.0 to 7.5:1.0, depending on reaction time and the size of the fatty acyl chain. The regiospecific synthesis of 6- O-acyl-4- O-sulfosucrose derivatives was accomplished by nucleophilic substitution of the sucrose 4,6-cyclic sulfate using various fatty acids. The amphoteric 6-alkylamino-6-deoxy-4- O-sulfosucrose surfactants were also synthesized by nucleophilic substitution of the sucrose cyclic sulfate by different fatty amines. All the newly synthesized sucrose-based surfactants displayed excellent surface-active properties.

Ozone-cleavable gemini surfactants, a new candidate for an environmentally friendly surfactant

Three types of gemini surfactants bearing carbon–carbon double bond(s) showed excellent surface-active properties, and readily decomposed into non-surface-active fragments and/or single-chain surfactants with different surface-active properties upon exposure to ozone in water.

Development of biochemicals-functionalization of biosurfactants and natural dyes

Under the aspect of environmental protection an increased demand for natural fine chemicals has been observed. From this viewpoint, this paper reviews current works on biodyes and attempts to describe their new functions. Biosurfactants have remarkably excellent surface active properties in spite of their bulky molecular structures, as well as good biodegradabilities and safety for living organisms. Furthermore, rhamnolipid A and B, produced by a hydrocarbon-assimilating bacterium, showed pH-sensitive conversion of molecular aggregates in the form of micelles, lipid particles, lamella, and vesicles. Curcumin derivatives were prepared to achieve a lasting color of the original dye, and the characteristics of microbial pyocyanine as a biodye were investigated. Hybrids of pyrene and biosurfactants were prepared to monitor the microenvironmental conditions of various kinds of colloidal surfaces and biointerfaces with respect to their polarity and fluidity.

Production of a biosurfactant exhibiting excellent emulsification and surface active properties bySerratia marcescens

A biosurfactant exhibiting excellent emulsification activity and surface properties was isolated during growth ofSerratia marcescens on 2% (w/v) sucrose. Reduction in surface tension values and increase in the yield of biosurfactant during the late log phase of growth indicates that the biosurfactant is a secondary microbial metabolite. The biosurfactant formed stable emulsions with a wide variety of hydrocarbons. The isolated surface-active compound has a potential application in enhanced oil recovery and is stable over a wide range of temperatures (10-120‡C) and pH (2-12). This is the first report of effective and stable emulsion formation by a strain ofSerratia marcescens.

Surface-active properties of rhamnolipids from Pseudomonas aeruginosa GS3.

Pseudomonas aeruginosa GS3 produced rhamnolipid biosurfactants during growth on carbohydrates, higher chain length n-alkanes and l-alkenes, petroleum crude oil and vegetable oils. With glucose as the substrate, maximum surfactant production (0.44 g/l) was observed during the stationary phase of growth. Partially purified rhamnolipids showed excellent surface-active properties in terms of reduction in the interfacial tension between them and a variety of hydrocarbons, hydrocarbon mixtures and vegetable oils and formation of stable emulsion.

Fluoroalkylated Oligo-Surfactants

Synthesis and properties of a series of fluoroalkylated oligomers by using fluoroalkanoyl peroxides have been reviewed. The synthetic methods of fluoroalkylated acrylic acid, nonionic, and cationic oligomers were illustrated. These fluoroalkylated oligomers, in particular, fluoroalkylated acrylic acid, nonionic, and cationic oligomers were in general shown to become soluble not only in water but also in common organic solvents such as methanol, ethanol, dimethyl sulfoxide, benzene and toluene. These fluoroalkylated oligomers have quite unique structure that fluoroalkyl groups are substituted only on the both terminals of oligomer chain, and can be regarded as double-chain type surfactant. They exhibit excellent surface active properties attributable to fluoroalkyl groups, such as quite low surface and interfacial tension, and anti-foaming property, and so on.Fluoroalkylated acrylic acid homo-and co-oligomers were demonstrated to exhibit a potent anti-HIV-1 activity in vitro. Furthermore, fluoroalkylated cationic oligomers were found to have an antibacterial activity. Therefore, these fluoroalkylated acrylic acid and cationic oligomers have been widely applicable to various fields as the novel functional materials which possess both a unique property imparted by fluorine and an anti-HIV-1 or antibacterial activity.

Synthesis and Properties of Soap Types of Cleavable Surfactants Bearing a 1, 3-Dioxolane Ring Derived from Long-chain Epoxides and Ethyl Levulinate

Sodium carboxylates of surfactants bearing a 1, 3-dioxolane ring were synthesized by reactions of epoxides and ethyl levulinate in the presence of BF3·Et2O as a catalyst at room temperature, followed by alkaline hydrolysis. Two surfactants, derived from long-chain alkyl epoxide or from long-chain alkyl glycidyl ether, respectively, showed excellent surface-active properties and good acid-decomposition. The latter surfactants from alkyl glycidyl ether had higher water solubility and solubility in hard water compared to the corresponding former. Critical micelle concentration (cmc) and area per molecule at the surface of the latter somewhat exceeded those of the former. The hydrophilicity and bulkiness of the oxymethylene group in the side chain of the 1, 3-dioxolane ring may have been responsible for this.