Folitixorin Calcium

Edible bird's nest (EBN) is a functional food renowned for its numerous health benefits. While its nutritional and therapeutic value is well-documented, the metabolites contributing to the bioactivities of EBN remain poorly understood. This study aimed to identify the metabolites present in EBN subjected to different treatments, including double-boiled EBN (EBN_db), EBN hydrolysate (EBN_hydro), EBN fermented with Lactobacillus helveticus (EBN_LH), Latilactobacillus curvatus (EBN_LC), and Latilactobacillus sakei (EBN_LS) using liquid chromatography-mass spectrometry (LC-MS) and correlate the identified bioactive metabolites with the bioactivities of EBN. It was found that the fermented EBNs exhibited the highest number of metabolites, with 76 tentatively identified, followed by EBN_hydro (45) and EBN_db (37). Citric acid (1.97-4.48 g/kg) was present in all treated EBN samples, while L(+)-lactic acid (3.03-8.07 g/kg) and adipic acid (2.33-3.18 g/kg) were only found in fermented EBNs. Among the treated EBN samples, EBN_LC demonstrated the significantly highest (p ≤ 0.05) antioxidative (22.34 ± 0.41 % 1,1-diphenyl-2-picrylhydrazil radical scavenging activity), antihypertensive (5.46 ± 0.26 % angiotensin-converting enzyme inhibitory activity), and antihyperglycemic activities (6.48 ± 0.34 % α-amylase inhibitory activity). A total of 18 metabolites, including citric acid, 4-sphingenin, N-acetylcitrulline, 4-aminophenol, L(+)-lactic acid, 2-oxoadipate, sildenafil, formylglycinamidin-RP, 11β,17α,21-α-5β-pregnane-3,20-dione, 2-ketobutyric acid, homoserine, benzaldehyde, 1-pyrroline4-hydroxy-2-carboxylate, nortriptyline, 1-methylguanine, 3-hydroxy-trimethyllysine, 3-phenylpropionate, and reserphine were predicted as bioactive metabolites using the partial least squares discriminant analysis (PLS-DA). This study provides valuable insights into the metabolites present in EBN and serves as fundamental data for future investigations into the bioactive compounds responsible for its specific health benefits, potentially leading to the development of enhanced EBN-based functional foods.

D-pantothenic acid (D-PA) is an essential vitamin that has been widely used in various industries. However, the low productivity caused by slow D-PA production in fermentation hinders its potential applications. In this study, strategies of engineering the synthetic pathway combined with regulating methyl recycle were employed in E. coli to enhance D-PA production. First, a self-induced promoter-mediated dynamic regulation of D-PA degradation pathway was carried out to improve D-PA accumulation. Then, to drive more carbon flux into D-PA synthesis, the key nodes of the R-pantoate pathway which encoded the essential enzyme were integrated into the genome. Subsequently, the further increase in D-PA production was achieved by promoting the regeneration of methyl donor. The strain L11T produced 86.03 g/L D-PA with a productivity of 0.797 g/L/h, which presented the highest D-PA titer and productivity to date. The strategies could be applied to constructing cell factories for producing other bio-based products.