Efficient Extraction of Astaxanthin from Phaffia rhodozyma with Polar and Non-polar Solvents after Acid Washing

method of extracting astaxanthin from Phaffia rhodozyma with various solvents after acid washing was investigated. The extraction efficiency was distinctly increased after acid washing of P. rhodozyma cells. When the concentration of HCl was 0.4 mol.L^-1, the highest extraction efficiency of astaxanthin was achieved which was about three times higher than the control. Acetone or benzene as single polar or non-polar solvent was the most ef- fective solvent in our research. With a combination of isopropanol and n-hexane （volume ratio of 2 ： 1）, the maxi- mal extraction efficiency was achieved, approximately 60% higher than that obtained with a single solvent. The liquid-solid ratio and the extracting time were also optimized. Under the optimum extraction conditions, the extraction yield of astaxanthin exceeded 98%.

Determination of Melamine in Quail Egg and Milk with Capillary Zone Electrophoresis

A capillary zone electrophoresis method was developed for determination of melamine in food samples, such as quail egg and milk products. The CE procedure was performed on fused silica capillary (41 cm × 75 μm I.D.) at 17 kV using pH3.1 60mmol/L phosphate buffer as run buffer and detecting at 200 nm. The proposed method showed good linearity (0.5 - 10.0 μmol/L) and low LOD (0.5 μmol/L) with good reproducibility (RSD% was 2.4 and 3.2 for migration time and peak area respectively), which made it suitable for quantity control of the related food product.

Boosted activity by engineering the enzyme microenvironment in cascade reaction: A molecular understanding

Engineering of enzyme microenvironment can surprisingly boost the apparent activity.However,the underlying regulation mechanism is not well-studied at a molecular level so far.Here,we present a modulation of two model enzymes of cytochrome c(Cty C)and D-amino acid oxidase(DAAO)with opposite pH-activity profiles using ionic polymers.The operational pH of poly(acrylic acid)modified Cyt C and polyallylamine modified DAAO was extended to 3-7 and 2-10 where the enzyme activity was larger than that at their optimum pH of 4.5 and 8.5 by 106%and 28%,respectively.The cascade reaction catalyzed by two modified enzymes reveals a 1.37-fold enhancement in catalytic efficiency compared with their native counterparts.The enzyme activity boosting is understood by performing the UV-vis/CD spectroscopy and molecular dynamics simulations in the atomistic level.The increased activity is ascribed to the favorable microenvironment in support of preserving enzyme native structures nearby cofactor under external perturbations.

INTRACELLULAR INOSITOL PHOSPHATES METABOLISM IN NIH 3T3 CELLS AFTER EXPOSURE TO ULTRAVIOLET LIGHT.

The relationship between inositol phosphates metabolism andinhibition of DNA synthesis was examined.The DNA synthesis ratemeasured by the [~3H]-labeled thymidine incorporation into cellularDNA in NIH3T3 fibroblast treated with UV indicates that there existsa resting stage of DNA synthesis in cells exposed to UV light.

Key molecules of Mucorales for COVID-19-associated mucormycosis:a narrative review

Mucormycosis is a lethal human disease caused by fungi of the order Mucorales.Mucormycosis is caused by fungi mainly belonging to the genera Mucor,Rhizopus,and Lichtheimia,all of which belong to the order Mucorales.The number of individuals with mucormycosis-causing disorders has increased in recent years,hence,leading to the spread of mucormycosis.Throughout the coronavirus disease 2019(COVID-19)pandemic,numerous cases of mucormycosis in COVID-19-infected patients have been reported worldwide,and the illness is now recognized as COVID-19-associated mucormycosis,with most of the cases being reported from India.Immunocompromised patients such as those with bone marrow sickness and uncontrolled diabetes are at a greater risk of developing mucormycosis.Genes,pathways,and other mechanisms have been studied in Mucorales,demonstrating a direct link between virulence and prospective therapeutic and diagnostic targets.This review discusses several proteins such as high-affinity iron permease(FTR1),calcineurin,spore coat protein(CotH),and ADP-ribosylation factors involved in the pathogenesis of mucormycosis that might prove to be viable target(s)for the development of novel diagnostic and therapeutic methods.