Engineering Escherichia coli for high-yielding 2,5-Dimethylpyrazine synthesis from L-Threonine by reconstructing metabolic pathways and enhancing cofactors regeneration.

2,5-Dimethylpyrazine (2,5-DMP) is important pharmaceutical raw material and food flavoring agent. Recently, engineering microbes to produce 2,5-DMP has become an attractive alternative to chemical synthesis approach. In this study, metabolic engineering strategies were used to optimize the modified Escherichia coli BL21 (DE3) strain for efficient synthesis of 2,5-DMP using L-threonine dehydrogenase (EcTDH) from Escherichia coli BL21, NADH oxidase (EhNOX) from Enterococcus hirae, aminoacetone oxidase (ScAAO) from Streptococcus cristatus and L-threonine transporter protein (EcSstT) from Escherichia coli BL21, respectively.

The role of cellular senescence-related genes in Asthma: Insights from bioinformatics and animal experiments.

Background: Asthma is a heterogeneous chronic respiratory disease, affecting about 10% of the global population. Cellular senescence is a multifaceted phenomenon defined as the irreversible halt of the cell cycle, commonly referred to as the senescence-associated secretory phenotype. Recent studies suggest that cellular senescence may play a role in asthma.

Bioinformatic mapping of a more precise Aspergillus niger degradome.

Aspergillus niger has the ability to produce a large variety of proteases, which are of particular importance for protein digestion, intracellular protein turnover, cell signaling, flavour development, extracellular matrix remodeling and microbial defense. However, the A. niger degradome (the full repertoire of peptidases encoded by the A.

Efficient expression of novel glutamate decarboxylases and high level production of γ-aminobutyric acid catalyzed by engineered Escherichia coli.

Glutamate decarboxylase (GAD) has the potential of converting L-glutamate to gamma-aminobutyric acid (GABA), which is an important non-proteinogenic amino acid that has a potential use as food additive or dietary supplement for its physiological functions. A novel pyridoxal 5'-phosphate (PLP)-dependent glutamate decarboxylase (LsGAD) was cloned from GRAS (generally recognized as safe) Lactobacillus senmaizukei by genome mining and efficiently expressed in Escherichia coli BL21. The LsGAD displayed excellent temperature property, pH property and kinetic parameters compared with the probe LbGAD and the other GADs.

Association of meteorological factors with pediatric acute appendicitis in China: A 7-year retrospective analysis.

Acute appendicitis (AA) affects between 7% and 8% of the world population and is one of the most common general surgical emergencies. The concept of seasonal patterns in the incidence of AA remains controversial. Thus, this study aimed to investigate whether meteorological factors are related to variations in the rate of pediatric AA cases at the Children's Hospital in Chongqing, China.

Bile salt hydrolases: Structure and function, substrate preference, and inhibitor development.

The worldwide trend of limiting the use of antibiotic growth promoters (AGPs) in animal production creates challenges for the animal feed industry, thus necessitating the development of effective non-antibiotic alternatives to improve animal performance. Increasing evidence has shown that the growth-promoting effect of AGPs is highly correlated with the reduced activity of bile salt hydrolase (BSH, EC 3.5.

Improved ethanol productivity from lignocellulosic hydrolysates by Escherichia coli with regulated glucose utilization.

Background: Lignocellulosic ethanol could offer a sustainable source to meet the increasing worldwide demand for fuel. However, efficient and simultaneous metabolism of all types of sugars in lignocellulosic hydrolysates by ethanol-producing strains is still a challenge.

Results: An engineered strain Escherichia coli B0013-2021HPA with regulated glucose utilization, which could use all monosaccharides in lignocellulosic hydrolysates except glucose for cell growth and glucose for ethanol production, was constructed.

A novel strategy for production of ethanol and recovery of xylose from simulated corncob hydrolysate.

Objectives: To develop a xylose-nonutilizing Escherichia coli strain for ethanol production and xylose recovery.

Results: Xylose-nonutilizing E. coli CICIM B0013-2012 was successfully constructed from E.

Exploring the Metabolomic Responses of to Temperature Stress by Gas Chromatography/Mass Spectrometry.

Owing to its high protein secretion capacity, simple nutritional requirements, and GRAS (generally regarded as safe) status, is widely used as a host for the industrial production of enzymes, antibiotics, and peptides. However, as compared with its close relative , little is known about the physiology and stress responses of . To explore its temperature-stress metabolome, strains ATCC 14580 and B186, with respective optimal growth temperatures of 42°C and 50°C, were cultured at 42°C, 50°C, and 60°C and their corresponding metabolic profiles were determined by gas chromatography/mass spectrometry and multivariate statistical analyses.

Periplasmic Export of Bile Salt Hydrolase in Escherichia coli by the Twin-Arginine Signal Peptides.

Bile salt hydrolase (BSH, EC 3.5.1.

Codon and Propeptide Optimizations to Improve the Food-grade Expression of Bile Salt Hydrolase in Lactococcus lactis.

To achieve the food-grade expression of bile salt hydrolase (BSH, EC 3.5.1.