ABSTRACT
With the increasingly serious eutrophication of global water bodies and the strict discharge standards of tail water in wastewater treatment plants (WWTPs), there is an urgent technology need for efficient deep phosphorus removal from wastewater. A composite cerium-based adsorbent (Ce-Zr-Al) was synthesized by coprecipitation method for the adsorption of low concentration phosphorus in water. The performance of the Ce-Zr-Al composite adsorbent was explored, and the mechanism was also revealed through the analyses including SEM, BET, XPS, and FT-IR. The results showed that the composite adsorbent had excellent phosphorus removal performance. The phosphorus removal rate reached up to 92.6%, and the phosphorus concentration in effluent was less than 0.074 mg/L. The phosphate adsorption capacity of saturation was 73.51 mg/g. The adsorption process of phosphate was in accordance with pseudo-second-order kinetic model and Langmuir model. In addition, the composite adsorbent had a high zero potential point (pH PZC= 8) and a wide range of pH application. After the repeated desorption for 10 times in NaOH solution, the composite adsorbent still maintained good adsorbability (adsorption rate > 94%). The ligand exchange and electrostatic adsorption played the main role for the phosphorus removal from water using the composite adsorbent.
Subject(s)
Phosphorus , Water Pollutants, Chemical , Wastewater , Adsorption , Spectroscopy, Fourier Transform Infrared , Water Pollutants, Chemical/analysis , Phosphates/analysis , Kinetics , Water/analysis , Hydrogen-Ion ConcentrationABSTRACT
BACKGROUND: Black garlic (Allium sativum L.) melanoidins (MLDs) are produced by Maillard reaction under high temperature and high humidity, and has a variety of biological activities. The aim of this study was to analyze the structural characteristics and investigate α-amylase and α-glucosidase in vitro inhibitory activity of black garlic MLDs. RESULTS: Spectroscopic and chemical analysis revealed that black garlic MLDs were heterogeneous macromolecular polymers with a skeletal structure similar to sugar chains. Molecular weight distribution and 3DEEM fluorescence showed that black garlic MLDs were composed of high-molecular-weight colorants with strong fluorescence properties. The polarity of black garlic MLDs was related to the fluorescence groups. The results of physicochemical properties proved that the polarity difference of black garlic MLDs was related to the elemental composition, resulting in differences in fluorescence, thermodynamic and apparent characteristics. MLDs with higher levels of fluorescent intensity (BG20 and BG40) had stronger inhibitory effects on α-amylase and α-glucosidase than BGW, and hydrolysis of fluorescent groups attenuated the inhibitory activity. The median inhibitory concentration (IC50 ) of black garlic MLDs against enzymes was positively correlated with the concentration, and the kinetic results detected non-competitive and mixed types of inhibition. CONCLUSION: High-molecular-weight fluorescent components of black garlic MLDs played a crucial role in the inhibitory activities of α-amylase and α-glucosidase, and the inhibitory ability was positively correlated with concentration. Black garlic MLDs had the potential to block postprandial glucose rise. © 2023 Society of Chemical Industry.
Subject(s)
Garlic , Garlic/chemistry , alpha-Amylases/antagonists & inhibitors , alpha-Glucosidases/metabolism , Glycoside Hydrolase Inhibitors/chemistry , Glycoside Hydrolase Inhibitors/pharmacology , Chemical PhenomenaABSTRACT
Cyperus esculentus is widely representing one of the important oil crops around the world, which provides valuable resources of edible tubers called tiger nut. The chemical composition and high ability to produce fats emphasize the role of tiger nut in promoting oil crop productivity. However, the underlying molecular mechanism of the production and accumulation of lipids in tiger nut development still remains unclear. Here, we conducted comprehensive transcriptomics and lipidomics analyses at different developmental stages of tuber in Cyperus esculentus. Lipidomic analyses confirmed that the accumulation of lipids including glycolipids, phospholipids, and glycerides were significantly enriched during tuber development from early to mature stage. The proportion of phosphatidylcholines (PC) declined during all stages and phosphatidyl ethanolamine (PE) was significantly declined in early and middle stages. These findings implied that PC is actively involved in triacylglycerol (TAG) biosynthesis during the tubers development, whereas PE may participate in TAG metabolism during early and middle stages. Comparative transcriptomics analyses indicated several genomic and metabolic pathways associated with lipid metabolism during tuber development in tiger nut. The Pearson correlation analysis showed that TAG synthesis in different developmental stages was attributed to 37 candidate transcripts including CePAH1. The up-regulation of diacylglycerol (DAG) and oil content in yeast, resulted from the inducible expression of exogenous CePAH1 confirmed the central role of this candidate gene in lipid metabolism. Our results demonstrated the foundation of an integrative metabolic model for understanding the molecular mechanism of tuber development in tiger nut, in which lipid biosynthesis plays a central role.