Transferring of red Monascus pigments from nonionic surfactant to hydrophobic ionic liquid by novel microemulsion extraction

doi:10.1016/j.seppur.2014.09.035

Separation and Purification Technology

Volume 138, 10 December 2014, Pages 34-40

https://doi.org/10.1016/j.seppur.2014.09.035 Get rights and content

Highlights

•
Extractive fermentation of red Monascus pigments in nonionic surfactant micelle aqueous solution.
•
Downstream processing of extractive fermentation.
•
Transferring of Monascus pigments from nonionic surfactant to ionic liquid by novel Winsor I microemulsion extraction.
•
Back-extraction of Monascus pigments from ionic liquid by water–ionic liquid two-phase extraction.

Abstract

Nonionic surfactant micelle aqueous solution as well as cloud point system is a potential separation/reaction medium. Downstream processing for recovery of product and regeneration of surfactant is indispensable. Adjustment of pH in the dilute phase of cloud point extraction is a common strategy for separation of ionizable organic compound from nonionic surfactant. However, this strategy is no longer suitable for recovery of ionizable organic compound with strong hydrophobicity due to the high solubilization of the ionic state of hydrophobic organic compound in micelles. Setting extractive fermentation of intracellular Monascus pigments in nonionic surfactant micelle aqueous solution to produce high color hue of red Monascus pigments as an example, transferring of hydrophobic Monascus pigments from nonionic surfactant to ionic liquid by novel hydrophobic ionic liquid–nonionic surfactant–water Winsor I microemulsion extraction and then back-extraction of the ionizable Monascus pigments from the ionic liquid by ionic liquid–water two-phase extraction were carried out. Nearly 80% yield was achieved in the complete process for recovery of Monascus pigments. It provides a novel strategy for stripping of hydrophobic ionizable organic compound from nonionic surfactant micelle aqueous solution.

Introduction

Surfactant forms micelles in an aqueous solution. Surfactant micelles have the capability to solubilize various species with a very broad polar spectrum, which makes surfactant micelle aqueous solution study extensively as reaction and separation media, such as micellar catalysis for solving the agent incompatibility in preparative organic chemistry [1], [2], [3]. Especially, nonionic surfactant micelle aqueous solution separates into a dilute phase and coacervate (surfactant-rich) phase above a certain temperature. This two-phase system is known as cloud point system and the phase separation temperature is called cloud point. Application of cloud point system for extraction of metal ions, organic compounds, and biomaterials is a well known technique in analysis field [4]. Due to the excellent biocompatibility of nonionic surfactant, nonionic surfactant micelle aqueous solution is also applied as a non-aqueous medium for enzymatic reaction, such as elimination of lignin inhibitor in the enzymatic saccharification of cellulose [5]. Our group has developed cloud point system as a novel medium of extractive fermentation for enhancement of hydrophobic compound solubility, elimination of product inhibition, and prevention of product from further degradation [6], [7].

Submerged culture of Monascus anka produces at least six molecular structures of pigments, which are classified into three groups based on their colors, i.e. yellow pigments (monascin and ankaflavin), orange pigments (monascorubrin and rubropunctation), and red pigments (monascorubramine and rubropuntamine) [8]. The major components of Monascus pigments are strongly depended on the nutrients in culture medium as well as culture condition (such as pH). The hydrophobic Monascus pigments are majorly accumulated intracellularly in conventional submerged aqueous culture. Recently, nonionic surfactant micelle aqueous solution is further developed for extractive fermentation of intracellular Monascus pigments [9], in which secretion of intracellular product and regulation of secondary microbial metabolites are fulfilled at the same time [10], [11]. Especially, extractive fermentation in the nonionic surfactant Triton X-100 micelle aqueous solution with high MSG (monosodium glutamate) concentration produces the high color hue of red Monascus pigment derivates with MSG (monosodium glutamate) residue (Fig. 1). The Monascus pigments are ionizable products with relatively strong hydrophobicity (log P is approximately 2 for its nonionic form while 0.3 for its ionic form [12]). Organic product in its ionic state has very limited solubilization in the nonionic surfactant micelles or the coacervate phase of cloud point system. Thus, most of ionizable products can be back-extracted from nonionic surfactant micelle aqueous solution by cloud point extraction via the adjustment of pH in dilute phase [13], [14], [15], [16], [17]. However, hydrophobic ionizable product in its ionic state prefers to partition into the coacervate phase of cloud point system [18], [19], [20], which makes adjustment of pH no longer suitable for back-extraction of the hydrophobic ionizable product from nonionic surfactant.

Thanks to the discovery of novel physical and chemical properties of ionic liquids (ILs), such as hydrophobic IL [Bmim]PF₆ (1-butyl-3-methylimidazolium hexafluorophosphate) exhibiting character of organic solvent. The organic solvent character of hydrophobic ILs has already utilized as a medium for hydrophobic IL–water two-phase extraction [21]. Meanwhile, hydrophobic IL [Bmim]PF₆, which replaces the organic solvent in organic solvent–nonionic surfactant Triton X-100–water ternary system, forms a novel [Bmim]PF₆-nonionic surfactant Triton X-100–water ternary Winsor I microemulsion, where oil in water microemulsion phase (W_m) coexists with excess IL phase [22]. The corresponding conventional Winsor I microemulsion (organic solvent–nonionic surfactant–water ternary system) extraction has been studied extensively for stripping of organic product from nonionic surfactant micelle aqueous solution. However, there is conflict between the extractive capacity of excess oil phase and the forming of W_m phase. In generally, relatively strong polar organic solvents have high extractive capacity while the nonionic surfactant is also partially extracted into the excess oil phase [23]. Similar to the conventional Winsor I microemulsion extraction, hydrophobic ILs provide the chance for transferring organic product from nonionic surfactant micelle aqueous solution to excess IL phase by the novel Winsor I microemulsion extraction. Furthermore, the peculiar characters of hydrophobic ILs also lead to the novel Winsor I microemulsion extraction have some potential advantages, such as relatively high phase transfer temperature (81 °C) [24] for operation at room temperature, very limited solubility of [Bmim]PF₆ in water at room temperature for removal of the contaminated nonionic surfactant in the excess IL phase by washing with water [25], and extraction of organic compounds with broad polar spectrum [21].

In the present work, recovery of Monascus pigments (Fig. 1) from extracellular broth after extractive fermentation in nonionic surfactant micelle aqueous solution was set up as a model of stripping hydrophobic ionizable organic product from nonionic surfactant micelle aqueous solution. First, the impossibility of recovery of Monascus pigments from nonionic surfactants by adjustment of pH in cloud point extraction was checked experimentally. Then, the effect of pH on transferring of Monascus pigments from nonionic surfactant micelle aqueous solution to excess [Bmim]PF₆ phase by Triton X-100–[Bmim]PF₆–water Winsor I microemulsion extraction was examined. Finally, adjustment of pH for back-extraction of Monascus pigments from IL by [Bmim]PF₆–water two-phase extraction was demonstrated.

Section snippets

Extractive fermentation of Monascus pigments

Extractive fermentation of red Monascus pigment derivates with MSG residue (Fig. 1) in Triton X-100 micelle aqueous solution was conducted following in a similar procedure to our previous work [10]. M. anka (China Center of Industrial Culture Collection, CICC 5013) was maintained on potato dextrose agar (PDA) medium (potato 200 g, glucose 20 g and agar 15–20 g, per liter of tap water) at 4 °C. Inoculum culture was conducted at 30 °C and 200 rpm for 30 h in a 250 ml Erlenmeyer flask with 50 ml of working

Cloud point extraction of Monascus pigments

After extractive fermentation in nonionic surfactant micelle aqueous solution, the spectrum (representing with photometric reading) of Monascus pigments in the extracellular broth was determined (Fig. 2A). The spectrum of Monascus pigments had a broad absorbance with two peaks at approximately 430 nm and 510 nm, which consisted with the major components of pigments were red Monascus pigments with MSG residue (Fig. 1). The red Monascus pigments with MSG residue have the characteristic absorbance

Discussion

Stripping of organic compound from surfactant micelle aqueous solution is strongly depended on the character of the organic compound and the surfactant. Based on the character of surfactant, degradable surfactant can be removed before the further recovery of product, such as biodegradation of bio-surfactant for de-emulsification during microbial fermentation [26]. Based on the character of solute, low boiling point product can be easily recovered by evaporation due to the high boiling point of

Conclusions

Application of nonionic surfactant micelle aqueous solution (cloud point system) as separation/reaction medium, the down-stream processing for recovery of product and regeneration of surfactant is indispensable. Setting extractive fermentation of intracellular Monascus pigments in nonionic surfactant micelle aqueous solution to produce high color hue of red Monascus pigments as an example, transferring of hydrophobic Monascus pigments from nonionic surfactant to IL by novel Winsor I

Acknowledgments

The financial supports from the National Natural Science Foundation of China (No. 21276155) and the Innovation Practice Program for SJTU Students (No: IPP 9146) are acknowledged.

References (38)

Z. Wang et al.
Fractal kinetic analysis of polymers/nonionic surfactants to eliminate lignin inhibition in enzymatic saccharification of cellulose
Bioresour. Technol.
(2011)
Z. Wang
The potential of cloud point system as a novel two-phase partitioning system for biotransformation
Appl. Microbiol. Biotechnol.
(2007)
Z. Wang et al.
Extractive microbial fermentation in cloud point system
Enzyme Microb. Technol.
(2010)
B. Kang et al.
Effect of pH and nonionic surfactant on profile of intracellular and extracellular Monascus pigments
Process Biochem.
(2013)
B. Kang et al.
Production of citrinin-free Monascus pigments by submerged culture at low pH
Enzyme Microb. Technol.
(2014)
T. Ingram et al.
Partition coefficients of ionizable solutes in aqueous micellar two-phase systems
Chem. Eng. J.
(2013)
J.J.A. Rendleman
Enhanced production of y-cyclodextrin from corn syrup solids by means of cyclododecanone as selective complexant
Carbohydr. Res.
(1993)
M. Topf et al.
Product recovery in surfactant-based separation processes: pervaporation of toluene from concentrated surfactant solutions
J. Membr. Sci.
(2013)
T. Pan et al.
Stripping of nonionic surfactant from coacervate phase of cloud point system for lipase separation by Winsor II microemulsion extraction with direct addition of alcohols
Process Biochem.
(2010)
R. Liang et al.
Novel polyethylene glycol induced cloud point system for extraction and back-extraction of organic compounds
Sep. Purif. Technol.
(2009)

A.M. Ferreira et al.

Complete removal of textile dyes from aqueous media using ionic-liquid-based aqueous two-phase systems

Sep. Purif. Technol.

(2014)

T. Ingram et al.

Modeling of pH dependent n-octanol/water partitioning coefficients of ionizable pharmaceuticals

Fluid Phase Equilibr.

(2011)

I.V. Berezin et al.

Physicochemical foundations of micellar catalysis

Russ. Chem. Rev.

(1973)

T. Dwars et al.

Reactions in micellar systems

Angew. Chem. Int. Ed.

(2005)

K. Holmberg

Organic reactions in microemulsion

Eur. J. Org. Chem.

(2007)

W.L. Hinze et al.

A critical review of surfactant-mediated phase separations (cloud-point extraction): theory and applications

Crit. Rev. Anal. Chem.

(1993)

P. Juzlova et al.

Secondary metabolites of the fungus Monascus: review

J. Ind. Microbiol.

(1996)

Z. Hu et al.

Perstraction of intracellular pigments by submerged cultivation of Monascus in nonionic surfactant micelle aqueous solution

Appl. Microbiol. Biotechnol.

(2012)

H. Jung et al.

Color characteristics of Monascus pigments derived by fermentation with various amino acids

J. Agric. Food Chem.

(2003)

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Transferring of red Monascus pigments from nonionic surfactant to hydrophobic ionic liquid by novel microemulsion extraction

Highlights

Abstract

Introduction

Section snippets

Extractive fermentation of Monascus pigments

Cloud point extraction of Monascus pigments

Discussion

Conclusions

Acknowledgments

Bioresour. Technol.

Appl. Microbiol. Biotechnol.

Enzyme Microb. Technol.

Process Biochem.

Enzyme Microb. Technol.

Chem. Eng. J.

Carbohydr. Res.

J. Membr. Sci.

Process Biochem.

Sep. Purif. Technol.

Sep. Purif. Technol.

Fluid Phase Equilibr.

Physicochemical foundations of micellar catalysis

Russ. Chem. Rev.

Reactions in micellar systems

Angew. Chem. Int. Ed.

Organic reactions in microemulsion

Eur. J. Org. Chem.

A critical review of surfactant-mediated phase separations (cloud-point extraction): theory and applications

Crit. Rev. Anal. Chem.

Secondary metabolites of the fungus Monascus: review

J. Ind. Microbiol.

Perstraction of intracellular pigments by submerged cultivation of Monascus in nonionic surfactant micelle aqueous solution

Appl. Microbiol. Biotechnol.

Color characteristics of Monascus pigments derived by fermentation with various amino acids

J. Agric. Food Chem.