Torularhodin and Torulene: Bioproduction, Properties and Prospective Applications in Food and Cosmetics - a Review

Torularhodin and torulene are two widespread microbial carotenoids with relatively few studies, as compared to other nutraceutical carotenoids such as β-carotene, lycopene and astaxanthin. Several genera of microorganisms produce it in high concentration (up to 0.1% of the cell dry weight), probably as a protection against photooxidation and free radicals. These pigments, which differ by a terminal carboxylic group, have provitamin-A activity and, being red, have potential use as food and cosmetic color additives. Several factors affect the biosynthesis of these substances, including: the composition of culture media, light irradiation, which may enhance the carotenoid production up to 25% of the non-irradiated cultures, and temperature, which changes the carotenoid balance towards more of the acidic carotenoid (torularhodin) or the hydrocarbon (torulene). The biomass may be directly extracted using non polar solvents such as hexane or a hexane-acetone mixture, without need of cell disruption. Extensive purification is not needed for using the pigments as food or cosmetic additives, but it is still necessary to evaluate the bioactivity of the pigments in humans.

A Comparison of Cell Disruption Procedures for the Recovery of Intracellular Carotenoids from Sporobolomyces Ruberrimus H110.

Carotenoids are intracellular pigments produced by microorganisms, including some species of yeasts, in the stationary phase of growth by the secondary metabolic pathways. In the present study, different methods of Sporobolomyces ruberrimus H110 yeast cell lysis were evaluated with the objective of optimizing the recovery of intracellular pigments. Three extraction methods were used: vortex (glass beads and quartz stones), planetary mill (glass beads and quartz stones) and dimethyl sulfoxide. For each one of the lysis agents studied, factorial designs were developed considering as independent variables the agitation speed and lysis agent concentration. A central composite planning was defined considering as independent variables the lysis agent concentration and agitation speed, analyzing as response the estimated total number of extracted carotenoids. From the methods studied, a better extraction of total carotenoid (1.74 mg.g-1 of cells and of 1.57 mg.g-1 of cells) using the planetary mill method with 135 mg of glass beads or irregular quartz stones, with an agitation speed of 200 rpm. As to the cell lysis, the analysis indicated that the mechanical methods studied showed to be efficient in regards to cell laceration.