β-Galactosidase production using glycerol and byproducts: Whey and residual glycerin

Porungo cheese whey: a new substrate to produce β-galactosidase

The bioconversion of porungo cheese whey to produce β-galactosidase in batch system was studied. The whey released after curd cutting and precipitation during porungo cheese production was collected in borosilicate flasks. Two strains of Kluyveromyces marxianus, CCT 4086 and CBS 6556, and whey supplementation with different nitrogen sources were evaluated. Different temperatures (30 °C and 37 °C) and pH values (5.0 to 7.0) were investigated to establish the best conditions for enzyme production. The highest enzymatic activity was obtained by K. marxianus CCT 4086 in porungo cheese whey supplemented with yeast extract (16.73 U mL-1). K. marxianus CCT 4086 produced superior β-galactosidase activity when compared to CBS 6556 for all media tested (ranging from 11.69 to 14.40 U mL-1). Highest β-galactosidase activity was reached under conditions of pH 7.0 and 30 °C using K. marxianus CCT 4086 in the better media composition. The lowest enzymatic activity was observed at 37 °C for all pH values tested (10.69 U mL-1 to 13.94 U mL-1) and a highest β-galactosidase activity was reached in pH 7.0 for both two temperatures (11.42 to 15.93 U mL-1). Porungo cheese whey shows potential for industrial β-galactosidase production by microbial fermentation.

Development and Characterization of Electrospun Nanostructures Using Polyethylene Oxide: Potential Means for Incorporation of Bioactive Compounds

The development of processes for stabilization of the properties of bioactive compounds has been studied in recent years, and the use of nanotechnology is among the most discussed routes. The present work addressed the assembly of nanostructures using polyethylene oxide (PEO), the production of core-shell nanofibers (NFs) with bioactive compounds, and the evaluation of their microscopic and physical characteristics. Aqueous solutions of PEO were electrospun by varying different process and solution parameters (PEO and NaCl concentrations, feeding rate, the tip-to-collector distance (TCD), and applied voltage) in order to optimize production of nanostructures. The best condition obtained was evaluated to form core-shell NFs composed by jussara pulp as a source of anthocyanins. To assess the production of NFs with PEO and jussara pulp, feed solutions were prepared in acetate buffer (pH 4.5) with 6% PEO and 10% lyophilized jussara pulp, at a feeding rate of 150 μL·h−1 and TCD of 15 cm using an applied voltage of 10 kV to form core-shell NFs. The results revealed the formation of core-shell NFs with a diameter of 126.5 ± 50.0 nm. The outcomes achieved represent a crucial step in the application of anthocyanins in food systems as pigments, establishing a basis for further research on the incorporation of nanomaterials into foodstuff.

Development of a novel integrated process for co-production of β-galactosidase and ethanol using lactose as substrate

A novel integrated process was developed successfully for co-production of β-galactosidase and ethanol using lactose as substrate, containing fermentation (Kluyveromyces lactis), isolation, permeabilization (a new recycling process) and spray drying. Firstly, a new fed-batch strategy optimized co-produced β-galactosidase at 105.91U/mL and ethanol at 32.16mg/mL, 4.40-fold and 10.82-fold increase over the results from initial conditions, respectively. Then a new mathematic model for the recycling permeabilization was established successfully. As expected, the total cells sediment from isolation of the fed-batch culture was permeabilized completely by distilled ethanol from broth supernatant. More amazedly, the specific activity of β-galactosidase product by spray drying the permeabilized cells reached 2.61U/mg, meeting the demand of commercial products. Furthermore, the ethanol product at 33.8% (v/v) was obtained from the novel integrated process, which could be applied for various applications. To conclude, the novel integrated process might be a feasible strategy to scale up for industrialization.