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In biotechnology there is a need for new purification and concentration processes for biologically active compounds such as proteins, enzymes, nucleic acids, or cells that combine a high selectivity and biocompatibility with an easy scale-up. A liquid-liquid extraction with a reversed micellar phase might serve these purposes owing to its capacity to solubilize specific biomolecules from dilute aqueous solutions such as fermentation and cell culture media. Reversed micelles are aggregates of surfactant molecules containing an inner core of water molecules, dispersed in a continuous organic solvent medium. These reversed micelles are capable of selectively solubilizing polar compounds in an apolar solvent. This review gives an overview of liquid-liquid extraction by reversed micelles for a better understanding of this process

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The production of red pigments and citrinin by Monascus purpureus CCT3802 was investigated in submerged batch cultures performed in two phases: in the first phase, cells were grown on glucose, at pH 4.5, 5.5 or 6.5; after glucose depletion, pH was adjusted, when necessary, to 4.5, 5.5, 6.5, 7.0, 8.0 or 8.5, for a production phase. The highest total red pigments absorbance of 11.3 U was 16 times greater than the lowest absorbance and was achieved with growth at pH 5.5, followed by production at pH 8.5, which causes an immediate reduction of the intra cellular red pigments from 75% to 17% of the total absorbance. The lowest citrinin concentration, 5.5 mg L -1 , was verified in the same culture while the highest concentration, 55 mg L -1 , was verified in cultures entirely carried out at pH 5.5. An alkaline medium, besides promoting intra cellular red pigments excretion, strongly represses citrinin synthesis.

-The production of red pigments by Monascus ruber was evaluated utilizing complex culture media composed of glucose or sucrose (10 g/L), corn steep liquor (5 or 10 g/L) and monosodium glutamate (0, 5.0, 7.6, 11.4 or 15.2 g/L). Medium containing 10 g/L glucose, 5 g/L corn steep liquor and 7.6 g/L monosodium glutamate resulted the highest values of extracellular red pigment absorbance (20.7 U) and productivity (0.35 U/h). This medium also produced better results than using semi-synthetic medium with analytical grade reagents (12.4 U and 0.21 U/h). The cell growth was similar in both media (X ≅ 6.5 g/L), indicating that the capacity of the cells to produce red pigments was higher in complex culture media. In addition, in the complex culture medium, less of the intracellular red pigments accumulated than in semi-synthetic medium (9.1% and 30%, respectively).