Estudo de fermentações tipo batelada-alimentada utilizando soro de queijo como meio de cultura

19

Clonagem do gene laca em Kluyveromyces Marxianus para otimizar a produtividade da enzima beta-galactosidase

19

Avaliação das condições de produção da enzima transglutaminase microbiana em cultivos submerso e no estado sólido

13

Biotechnological production of galactooligosaccharides (GOS) using porungo cheese whey

The bioconversion of porungo cheese whey into galactooligosaccharides (GOS) was investigated using immobilized β-galactosidase in batch system. Two enzymatic immobilization strategies were tested for optima pH and temperature and the best immobilization strategy was used to evaluate the GOS production in two steps. First, different lactose sources (substrates) were tested, and subsequently, different concentrations of porungo cheese whey (200 g L-1 and 400 g L-1) and temperatures (37 °C to 46 °C) were evaluated. Immobilization of β-galactosidase increased the range of operational pH (7.0-7.5) when immobilized in calciumalginate support. However, the pH range decreased when the immobilization was conducted using calcium-Concanavalin A support. Batch reactions using the calcium-alginate immobilized biocatalyst produced the highest yields of GOS (63.2%) from porungo cheese whey, compared to the control substrate of lactose solution at concentration of 50 g L-1 (41.1%). The temperature of 46 °C and 400 g L-1 of substrate shown the better condition to GOS production, with lactose conversion of 61.4%. These results suggest the possible use of porungo cheese whey as substrate in the biotechnological production of GOS

Propriedades funcionais de proteínas tratadas com a enzima transglutaminase

12

Estudo da concentração da alimentação em cultivo tipo batelada-alimentada utilizando soro de queijo como meio de cultura

19

Utilização de um resíduo industrial fibroso de soja para a produção de celulases e xilanases em cultivo semi-sólido

18

Treatment and characterization of biomass of soybean and rice hulls using ionic liquids for the liberation of fermentable sugars

We investigated the changes in the physical structure of cellulose recovered from soybean and rice hulls treated with the ionic liquids 1-butyl-3-methylimidazolium chloride ([bmim][Cl]) and 1-butyl-3-methylimidazolium acetate ([bmim][Ac]). The characterization was carried out by a combination of thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Regenerated cellulose from soybean hull showed loss of crystallinity and high structural disruption caused by both ionic liquid treatments as compared to the untreated material. In contrast, rice hull presented only a small structural disruption when treated with [bmim][Ac] and was practically unaffected by [bmim][Cl], showing that this biomass residue is recalcitrance towards physico-chemical treatments, possibly as a consequence of its high composition content in silica. These results suggest the use of soybean hull as a substrate to be treated with ionic liquids in the preparation of lignocellulosic hydrolysates to be used in second-generation ethanol production, whereas other methods should be considered to treat rice hull biomass