The yeast Phaffia rhodozyma is known for producing carotenogenic pigments, commonly used in aquaculture feed formulation as well as in cosmetic, pharmaceutical, and food industries. Despite the high production of carotenoids from microorganisms by biotechnology, their use has limitation due to the cell wall resistance, which constitutes a barrier to the bioavailability of carotenoids. Therefore, there is a need to improve carotenoids recovering technique from microorganisms for the application of food industries. This study aimed to compare mechanical, chemical, and enzymatic techniques of cell disruption for extracting carotenoids produced by P. rhodozyma NRRL Y-17268. Among the techniques studied, the highest specific concentration of carotenoids (190.35 µg/g) resulted from the combined techniques of frozen biomass maceration using diatomaceous earth and enzymatic lysis at pH of the reaction medium of 4.5 at 55 o C, with initial activity of β-1,3 glucanase of 0.6 U/mL for 30 min.

The production of lipase by Geotrichum candidum in both, stirred tank and airlift bioreactors were compared. G candidum an imperfect filamentous fungus, grows well in liquid medium, and produces a lipase with specific affinity for long-chain fatty acids with cis-9 double bonds but, lipase production is generally not efficient because the optimum medium composition and fermentation conditions are not known. Response surface methodology was used to optimize the agitation speed (100-500 rpm) and aeration (0.2-1.8 vvm) for production of lipase by G candidum in a bench-scale stirred fermenter. A Central Composite Rotatable Design (CCRD) was used to optimize lipase activity and productivity. Lipase production in an airlift fermenter was also studied with aeration ranging from 1 to 3 vvm. A previously optimized culture medium containing 3.58% of peptone, 0.64% of soy oil and an initial pH of 7.0, was used in the experiments, incubating at 30• C. In the stirred reactor the optimum conditions of agitation and aeration for lipase production and productivity were 300 rpm and 1 vvm, leading to an activity of 20 U cm −3 in 54 h of fermentation and 0.3900 (U cm −3 h −1 ) of productivity. The best aeration condition in the airlift fermenter was 2.5 vvm, which yielded similar lipase activity after 30 h of fermentation, resulting in a productivity of 0.6423 (U cm −3 h −1 ). In the absence of mechanical agitation similar lipase yields were achieved but in less time, resulting in productivity, about 60% greater than in a stirred fermenter; the lower energy demand for the same lipase yield offers economic advantages.

C‐phycocyanin (C‐PC), a natural blue dye, has been used in food, immunodiagnostics and analytical reagents. In this paper, the optimization of the two‐stage extraction of C‐PC from Spirulina platensis cells was studied. First, the biomass underwent different treatments for cell disruption, including drying, freezing and milling at different levels, and the extraction was then carried out using fixed time, impeller rotational speed and biomass‐to‐solvent ratio. Having defined the cell rupture conditions, the extraction process was optimized, evaluating the effects of impeller rotational speed and biomass‐to‐solvent ratio with time using a factorial design and response surface techniques. The results were evaluated as functions of C‐PC concentration, purity and extraction yield. The optimum conditions for extracting C‐PC from dried, frozen biomass, milled to a small diameter, were an extraction time of 1 h, a biomass‐to‐solvent ratio 0.16:1, and without agitation, obtaining a C‐PC concentration of 13.20 mg/mL, purity of 0.603 and extraction yield of 82.48 mg/g. PRACTICAL APPLICATIONS This manuscript reports the extraction of C‐phycocyanin (C‐PC) using a method that can be scaled up. C‐PC can be used as a natural blue dye in the food industry as a substitute for artificial dyes, with the advantage that C‐PC is healthier and extracted from algal biomass. This paper presents the use of a complete factorial design to optimize the extraction of C‐PC from cyanobacteria using a procedure without the use of chemical products. This product can be used in foods, or suffer purification for use in the pharmaceutical industry since it shows some medical properties such as anti‐inflammatory and antitumoral effects.

SUMMARYCarotenoids are natural pigments that can be produced through biotechnological processes. However, the costs are relatively high and can be minimized by using lower-cost substrates as alternative nutrient sources. The fed-batch fermentation is one of the techniques used to obtain a high biomass concentration and/or maximum production. Thus, the aim of this work is to produce carotenoids in batch and fed-batch fermentation with the yeast Rhodotorula mucilaginosa CCT 7688 using agroindustrial byproducts in the culture medium. Carotenoid production was increased using experimental designs, which modified the concentration of the agroindustrial medium. In batch production the highest concentrations of total carotenoids (1248.5 μg/L) and biomass (7.9 g/L) were obtained in the medium containing 70 g/L sugar cane molasses and 3.4 g/L corn steep liquor at 25 °C and 180 rpm in 168 h, demonstrating an increase of 17% when compared to the standard yeast malt medium (1200 μg/L). In the fed-batch production, different feeding strategies were tested with 30 g/L sugar cane molasses and 6.5 g/L corn steep liquor, reaching a total carotenoid production of 3726 μg/L and biomass concentration of 16 g/L. Therefore, the strategy of the fed-batch process resulted in an increase in the carotenoid production of approx. 400% compared to that in the batch process (740.3 μg/L). Thus, the R. mucilaginosa strain has the potential to produce carotenoids in agroindustrial medium.