Isolation of natural red colorants from fermented broth using ionic liquid-based aqueous two-phase systems

Area of Science:

• Biotechnology
• Separation Science
• Natural Product Chemistry

Background:

• Growing demand for natural colorants necessitates efficient and sustainable extraction methods.
• Conventional separation techniques often lack selectivity and efficiency for complex biological matrices.
• Ionic liquids offer tunable properties for novel separation systems.

Purpose of the Study:

• To investigate ionic liquid-based aqueous two-phase systems (ATPS) for red colorant recovery from Penicillium purpurogenum.
• To optimize ATPS conditions for enhanced colorant yield, purity, and protein removal.
• To evaluate the potential of ATPS as a benign alternative for natural colorant extraction.

Main Methods:

• Screening of various ATPS formulations using quaternary ammonium and imidazolium ionic liquids.
• Fermentation of Penicillium purpurogenum DPUA 1275 to produce red colorants.
• Optimization of process parameters including ionic liquid type, pH, and tie-line length.
• Quantification of red colorant partition coefficients, protein removal efficiency, and selectivity.

Main Results:

• Specific ATPS formulations demonstrated effective separation of red colorants from contaminants.
• Optimized conditions (short alkyl chain quaternary ammonium, alkaline pH, short tie-line length) yielded high partition coefficients (K red = 24.4 ± 2.3).
• High protein removal (60.7 ± 2.8%) and selectivity (S red/prot = 10.05) were achieved.

Conclusions:

• Ionic liquid-based ATPS are a viable and efficient method for extracting natural red colorants.
• Process optimization allows for high purity and yield, meeting industrial demands.
• This approach offers a sustainable and benign alternative to traditional separation techniques.