Ammonium determination by merging-zone flow injection analysis and a naphthalene-based fluorescent probe.

This paper discusses the first-time study of a naphthalene-based fluorescent probe-naphthalene-2,3-dicarboxaldehyde (NDA), in combination with merging-zone flow injection analysis for the automated fluorescence determination of ammonium. The determination was contingent on detecting the fluorescent product of NDA-SO-NH, which has maximum excitation and emission wavelengths of 508 nm and 564 nm, respectively. And the possible sensing mechanism of NDA-NH was proposed.

Determination of ammonium in natural water using a quinoline-based -dialdehyde fluorescent reagent with visible excitation wavelength.

In this paper, a novel and stable fluorescent reagent, quinoline-2,3-dicarbaldehyde (QDA), is synthesized as a probe to detect ammonium in natural water. Ammonium reacts with QDA in the presence of SO and Ca to form a fluorescence product, which has maximum excitation and emission wavelengths at 429 nm and 518 nm. The concentration of reagents, the reaction temperature, the reaction time, and the pH in the final solution are investigated and optimized.

Reducing the cell lysis to enhance yield of acid-stable alpha amylase by deletion of multiple peptidoglycan hydrolase-related genes in Bacillus amyloliquefaciens.

Bacillus amyloliquefaciens is a major industrial host for extracellular protein production, with great potential in the enzyme industry. However, the strain has accelerated the autolysis drawback in the process of secreting extracellular enzymes, which can significantly lower the density of cells and decrease the product yield. To identify target genes, we employed comparative transcriptome sequencing and KEGG analysis to indicate the increased expression of peptidoglycan hydrolase-regulated genes from the exponential phase to the apoptotic phase of growth; this was further confirmed by quantitative RT-PCR.

Effect of Sargassum fusiforme polysaccharide on apoptosis and its possible mechanism in human erythroleukemia cells.

This study aimed to investigate the effects of Sargassum fusiforme polysaccharide (SFPS I, II, and III) on the apoptosis and regulation of human erythroleukemia (HEL) cells. The effect of different doses of SFPS on HEL cell growth was detected using the Cell Counting Kit-8 method, and apoptosis was detected by Hoechst staining. Cell cycle distribution and apoptosis were detected using flow cytometry.

Tunable physical and mechanical properties of gelatin hydrogel after transglutaminase crosslinking on two gelatin types.

The crosslinking and related gel properties of 3 wt% gelatin (type-A and type-B) catalyzed by microbial transglutaminase (MTG, dose of 0-20 U/g gelatin) have been investigated. A MTG-depended increase in the molecular weight and mean diameter of both gelatins was observed, where type-A presented a higher crosslinking efficiency than type-B due to more acyl donors of the former. As MTG concentration increased, the surface hydrophobicity and thermal stability of type-A gelatin increased.

Engineering a highly efficient expression system to produce BcaPRO protease in Bacillus subtilis by an optimized promoter and signal peptide.

Bacillus subtilis has been extensively utilized as a host to express heterologous protein used in various industrial processes. Hence, the secretory overproduction of recombinant proteins is highly dependent on the strong promoters and signal peptides with high efficiency in B. subtilis.