Encapsulating systems prepared with beta-lactoglobulin, the major component of whey protein, may serve as versatile bioavailability enhancers for poorly absorbed nutraceuticals.

ATP is indispensable to the biosynthesis of both S-adenosylmethionine (SAM) and glutathione (GSH) in yeast cells. To improve ATP supply for overproduction of SAM and GSH in Candida utilis CCTCC M 209298, an exogenous ATP6 gene from Arabidopsis thaliana was expressed in the parental strain to construct the mutant C. utilis ATP6 by genomic integration. The maximal production of SAM and GSH in the mutant increased by 46.6 and 28.7%, respectively, when compared with those obtained in the parental strain. The mechanism underlying improved SAM and GSH biosynthesis by exogenous ATP6 gene expression revealed that the mutant had higher activities of key enzymes involved in SAM and GSH biosynthesis as well as energy metabolism. Increased NADH availability and F F -ATPase activity subsequently resulted in improved ATP regeneration and intracellular ATP supply for SAM and GSH overproduction. The present study not only developed an effective method for improving SAM and GSH biosynthesis by energy metabolism regulation, but also offered a novel approach for efficient production of similar energy-consuming products in eukaryotic cells.

20Crosslinking is essential for maintaining the integrity of protein-based nanoparticles against 21 environmental fluctuations. However, conventional crosslinkers (e.g. glutaraldehyde) are 22 usually toxic and environmental unfriendly. In this study, a tyrosinase-aided crosslinking 23 procedure was developed and compared to the conventional glutaraldehyde-based process. 24Sodium caseinate (SC) nanoparticles were synthesized by ionic gelation or desolvation under 25 aqueous or alcoholic condition, respectively. The nanoparticles were stabilized by different 26 crosslinkers and challenged under simulated environmental stress, including acidification and 27 antisolvent removal. A simple based on dynamic light scattering (DLS) was developed to 28 evaluate the particle integrity, using the retention of particle size and count rate as indicators. 29Satisfying crosslinking was observed for the ionic gelation procedure in the presence of 30 tyrosinase (10 U/mol SC) combined with two phenols (catechol or chlorogenic acid, 2.5 31 mol/mol SC). In comparison, a higher dose of glutaraldehyde (7.5 mol/mol SC) was required 32 for achieving a comparable crosslinking effect. For the desolvation procedure, the efficacies 33 for both glutaraldehyde and tyrosinase-phenol blends decreased, although they were still 34 significant, and glutaraldehyde exhibited better crosslinking effect. The results from the DLS 35 study were in consistence with those obtained from scanning electron microscopy. Overall, 36 tyrosinase-aided oxidation is a competitive, low-toxicity approach for crosslinking 37 protein-based nanostructures. 38