Abstract In the present study, an innovative cultivation strategy of Rhodotorula mucilaginosa CCT 7688 to accumulate both lipids and high added value carotenoids was proposed, with the potential to contribute to the economic feasibility of microbial oils in comparison with vegetable oils. The stepwise fed-batch cultivation with crude glycerol feeding at 24 h, 96 h, and 144 h, with the addition of magnesium to the initial culture medium, resulted in a lipid content of 51.0 ± 0.3 % CDW, biomass concentration of 21.00 ± 0.48 g L-1, total lipid production of 10.72 ± 0.18 g L-1, lipid productivity of 0.037 ± 0.001 g L-1 h-1, volumetric carotenoid production of 2843.2 ± 282.0 μg L-1, and carotenoid productivity of 9.87 ± 0.98 μg L-1 h-1. These values represent a 6-fold increase in lipid content, a 19-fold increase in lipid production, and a 2-fold increase in carotenoid production compared to batch cultivation.

ABSTRACT Different yeast strains from forests located in southern Brazil, with potential to produce carotenoids, were isolated. Three microorganisms were selected as potential carotenoid producers. Sporiodiobolus pararoseus, Rhodotorula mucilaginosa and Pichia fermentans were grown in Yeast Malt (YM) medium and the carotenoids produced identified as cryptoxanthin and β-carotene. In order to reduce production costs, agroindustrial residues were used in the formulation of medium A (parboiled rice water and crude glycerol) and medium B (parboiled rice water and sugar cane molasses). The highest carotenoid production was obtained with S. pararoseus. It reached 905.30 μ gL-1 (122.82 μg g-1) in YM medium, 820 μg L-1 (68.04 μg g-1) in medium B and 710 μg L-1 (86.46 μg g-1) in medium A. R. mucilaginosa exhibited the best performance in medium B (360 μg L-1 and 30.16 μg g-1) and a new microorganism - P. fermentans - reached 48% (medium A) and 78% (medium B) of the value found in YM medium. Therefore, the agroindustrial residues under evaluation, which replaced the commonly used nitrogen and carbon sources in culture media, enabled the isolated yeasts to yield carotenoids.

Lipozyme TL IM foi usada para catalisar a esterificação de álcool isoamílico e ácido butírico. Um planejamento fatorial fracionário foi utilizado para avaliar os efeitos da temperatura (30, 40, 50 ºC), razão molar álcool:ácido (1:1, 2:1, 3:1), concentração de enzima (0,003, 0,0115, 0,020 g mL-1), concentração de ácido butírico (0,1, 0,3, 0,5 mol L-1) e agitação (50, 115, 180 rpm) na produção de éster. Com esses resultados, os níveis foram redefinidos para um planejamento fatorial 2³. A máxima produção de éster foi obtida a 30 ºC, 180 rpm, razão molar álcool:ácido de 1:1, concentração de enzima 0,021 g mL-1 e concentração de ácido butírico de 0,5 mol L-1. Sob essas condições ótimas foi obtido 92% de esterificação e concentração de éster de 0,9 mol L-1. Álcool isoamílico obtido a partir de óleo fúsel foi utilizado nas mesmas condições resultando em 93% de esterificação e concentração de éster de 1,0 mol L-1.

Lipozyme TL IM was used to catalyse the esterification of isoamyl alcohol and butyric acid. A fractional factorial design was employed to evaluate the effects of temperature (30, 40, 50 °C), alcohol:acid molar ratio (1:1, 2:1, 3:1), enzyme concentration (0.003, 0.0115, 0.020 g mL-1), butyric acid concentration (0.1, 0.3, 0.5 mol L-1) and shaking rate (50, 115, 180 rpm) on the ester yield. With these results, the levels were redefined to a 2³ factorial design. The maximum yield of ester was obtained at 30 ºC, 180 rpm, alcohol:acid molar ratio of 1:1, enzyme concentration of 0.021 g mL-1 and butyric acid concentration of 0.5 mol L-1. Under the optimal conditions, 92% esterification was attained with an ester concentration of 0.9 mol L-1. Isoamyl alcohol from fusel oil was used under the same conditions and resulted in 93% esterification and an ester concentration of 1.0 mol L-1.

C-ficocianina é um pigmento natural azul que pode ser utilizado como aditivo alimentar e na indústria farmacêutica. Esse trabalho visou obter C-ficocianina com aumento na pureza e sem perdas na recuperação, empregando a técnica da precipitação. O extrato bruto de C-ficocianina foi utilizado nos ensaios. A otimização da purificação foi feita através de um planejamento experimental, no qual avaliou-se a concentração de sulfato de amônio, o volume e o pH de tampão de re-suspensão. Subseqüentemente, um estudo da purificação utilizando o fracionamento com sulfato de amônio foi realizado nas melhores condições encontradas no planejamento experimental. As condições mais favoráveis para a purificação foram obtidas quando foi utilizado fracionamento com sulfato de amônio na faixa 0-20%/20-50%, relação volume de re-suspensão/volume inicial de 0,52 e tampão pH 7,0. Nessas condições, em um único passo de purificação, a pureza aumentou 70% comparado ao extrato inicial e a recuperação foi de 83,8%.

C-phycocyanin is a natural blue dye that has been used as an additive in food and can be used to produce medications. The major goal of the present study was to obtain C-phycocyanin under the best operational conditions for high C-phycocyanin recovery and purity using the precipitation technique. Crude C-phycocyanin from Spirulina platensis was used. Optimization of the purification was carried out using experimental design. The effect of ammonium sulfate concentration, volume and of pH for resuspension were evaluated. Subsequently an ammonium sulfate fractionation study was carried out using the most suitable conditions found in the experimental design. The best purification condition was ammonium sulfate fractionation at 0-20%/20-50%, in relation to a resuspension volume/initial volume of 0.52 in a 7.0 pH buffer. Under these conditions, in an one-step purification only, the purity increased 70% compared to the initial extract, with an 83.8% recovery.