This work aimed to evaluate the effect of sugar cane molasses and glycerol on glutathione (GSH) fermentation by Saccharomyces cerevisiae ATCC 7754 in flask culture using response surface methodology. Under optimized conditions (80 g/L of molasses and 60 g/L of glycerol), the highest GSH and biomass concentration achieved were 119.6 mg/L and 25.3 g/L, respectively. Further studies done in 5 L bioreactor resulted 241.3 mg/L GSH after 96 h in batch fermentation without amino acids addition and the concentration of biomass was 12.1 g/L. In batch fermentation with the addition of the three amino acids (4 mM cysteine, glycine and glutamic acid at 32 h), biomass reached to 25 g/L and GSH, 236.1 mg/L at 96 h of fermentation. The strategy of precursor amino acids addition is a key aspect in increasing the synthesis of GSH.

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.

Extrato aquoso de C-ficocianina de Spirulina platensis, com e sem resíduos celulares, foi purificado em sistema aquoso bifásico (SAB) polietilenoglicol (PEG)/fosfato de potássio variando-se a massa molar do PEG, a pH 6, mais promissor do que a pH 7. Para os ensaios realizados com cada massa molar, com diferentes percentuais de PEG e sal, as concentrações (mg mL-1), as purezas (OD 620/OD 280) e os coeficientes de partição da C-ficocianina de cada sistema foram determinados e comparados. O processo para a purificação primária de C-ficocianina intracelular com resíduos celulares (integrado), composto por 15% de PEG 1500 e 13% de fosfato de potássio de 5% de PEG 4000 e 18% de sal, alcançaram concentrações de C-ficocianina de, respectivamente, 1,60 e 2,67 mg mL-1 na fase de topo. As purezas foram de 0,73 e 0,79, respectivamente, valores superiores aos obtidos nos sistemas sem resíduos celulares.

Crude C-phycocyanin extracts from Spirulina platensis, with and without cell debris, were purified in aqueous two-phase systems ( ATPS) varying the molar mass of the PEG, at pH 6, more promising than at pH 7 . For the assays carried out with each molar mass, with distinct percentages of PEG and salt, the concentrations (mg mL-1), purities (OD 620/OD 280) and C-phycocyanin partition coefficients of each system were determined and compared. The process for the primary purification of intracellular C-phycocyanin with cell debris (integrated), composed of 15% of PEG 1500 and 13% of potassium phosphate and 5% of PEG 4000 and 18% of salt, produced C-phycocyanin concentrations of, respectively, 1.60 and 2.67 mg mL-1 in the top phase. The purities were of 0.73 and 0.79 respectively, values higher than those obtained in the systems without cells.

Isoamyl butyrate production was investigated using free and immobilized lipases by esterification of butyric acid with isoamyl alcohol in a solvent-free system and in an organic media. Among the enzymes studied, Lipozyme TL IM was found to be the most active catalyst in n-hexane as a solvent. The effects of different solvents and the amount of water added on conversion rates were studied. A maximum conversion yield of 80% in n-hexano at 48 h was obtained under the following conditions: 3 g L-1 of Lipozyme TL IM, 30 ºC, 180 rpm of agitation, isoamyl alcohol to butyric acid molar ratio of 1:1 and acid substrate concentration of 0.06 M.