Multilevel Systematic Optimization To Achieve Efficient Integrated Expression of .

Genomic integration of heterologous genes is the preferred approach in industrial fermentation-related strains due to the drawbacks associated with plasmid-mediated microbial fermentation, including additional growth burden, genetic instability, and antibiotic contamination. Synthetic biology and genome editing advancements have made gene integration convenient. Integrated expression is extensively used in the field of biomanufacturing and is anticipated to become the prevailing method for expressing recombinant proteins.

Engineering of human tryptophan hydroxylase 2 for efficient synthesis of 5-hydroxytryptophan.

L-Tryptophan hydroxylation catalyzed by tryptophan hydroxylase (TPH) presents a promising method for synthesizing 5-hydroxytryptophan (5-HTP), yet the limited activity of wild-type human TPH2 restricts its application. A high-activity mutant, MT10 (H318E/H323E), was developed through semi-rational active site saturation testing (CAST) of wild-type TPH2, exhibiting a 2.85-fold increase in k/K over the wild type, thus enhancing catalytic efficiency.

L-lysine production by systems metabolic engineering of an NADPH auto-regulated Corynebacterium glutamicum.

Here, the systems metabolic engineering of L-lysine-overproducing Corynebacterium glutamicum is described to create a highly efficient microorganism producer. The key chromosomal mutations associated with L-lysine synthesis were identified based on whole-genome sequencing. The carbon flux was subsequently redirected into the L-lysine synthesis pathway and increased the availability of energy and product transport systems required for L-lysine synthesis.

Geometric Remodeling of Nitrilase Active Pocket Based on ALF-Scanning Strategy To Enhance Aromatic Nitrile Substrate Preference and Catalytic Efficiency.

Nitrilase can catalyze nitrile compounds to generate corresponding carboxylic acids. Nitrilases as promiscuous enzymes can catalyze a variety of nitrile substrates, such as aliphatic nitriles, aromatic nitriles, etc. However, researchers tend to prefer enzymes with high substrate specificity and high catalytic efficiency.

Efficient secretory expression of phospholipase D for the high-yield production of phosphatidylserine and phospholipid derivates from soybean lecithin.

Phospholipase D (PLD) is an essential biocatalyst for the biological production of phosphatidylserine and phospholipid modification. However, the efficient heterologous expression of PLD is limited by its cell toxicity. In this study, a PLD was secretory expressed efficiently in with an activity around 100 U/mL.

Transcriptomics reveals the effect of ammonia nitrogen concentration on F2 assimilation and the analysis of function.

The biological treatment of wastewater with high concentrations of ammonia nitrogen has become a hot research issue, but there are limited reports on the mechanism of ammonia nitrogen utilization by microorganisms. In this paper, a transcriptomic approach was used to investigate the differences in gene expression at 500.0 mg/L (Amo 500) and 100.

An enzymatic colorimetric whole-cell biosensor for high-throughput identification of lysine overproducers.

L-lysine is a crucial nutrient for both humans and animals, and its main commercial use is as a supplement in animal feed to promote chicken and other animal growth. Fluorescence biosensors based on the transcriptional regulator have been developed for high-throughput screening of L-lysine producers. However, due to its inability to specifically detect lysine, this fluorescent biosensor cannot be employed to screen high-yielding strains.

Pathway engineering facilitates efficient protein expression in Pichia pastoris.

Pichia pastoris has been recognized as an important platform for the production of various heterologous proteins in recent years. The strong promoter AOX1, induced by methanol, with the help of the α-pre-pro signal sequence, can lead to a high expression level of extracellular protein. However, this combination was not always efficient, as protein secretion in P.

Industrial production of L-lysine in Corynebacterium glutamicum: Progress and prospects.

L-lysine is one of the amino acids necessary for humans and animals and widely used in food processing, pharmaceutical preparations and feed additives. In recent years, rational design based on systems metabolic engineering and conventional optimization of fermentation parameters have contributed to the high production of L-lysine. As the demand for L-lysine in the world market is increasing year by year, intensive research has been devoted to efficient productivity and economic production costs.

Enhancement of l-Pipecolic Acid Production by Dynamic Control of Substrates and Multiple Copies of the Gene in the Genome.

l-Pipecolic acid is an important rigid cyclic nonprotein amino acid, which is obtained through the conversion of l-lysine catalyzed by l-lysine cyclodeaminase (LCD). To directly produce l-pipecolic acid from glucose by microbial fermentation, in this study, a recombinant strain with high efficiency of l-pipecolic acid production was constructed. This study involves the dynamic regulation of the substrate concentration and the expression level of the l-lysine cyclodeaminase-coding gene .

Enhancing β-alanine production from glucose in genetically modified Corynebacterium glutamicum by metabolic pathway engineering.

To directly produce β-alanine from glucose by microbial fermentation, a recombinant Corynebacterium glutamicum strain with high efficiency of β-alanine production was constructed in this study. To do this, the biosynthetic pathway of β-alanine in an L-lysine-producing strain XQ-5 was modified by enhancing carbon flux in biosynthetic pathway and limiting carbon flux in competitive pathway. This study showed that replacement of L-aspartate kinase (AK) with wild-type AK and disruption of lactate dehydrogenase and alanine/valine aminotransferases increase β-alanine production because of decreasing the by-products accumulation.

Reconstruction of the Diaminopimelic Acid Pathway to Promote L-lysine Production in .

The dehydrogenase pathway and the succinylase pathway are involved in the synthesis of L-lysine in . Despite the low contribution rate to L-lysine production, the dehydrogenase pathway is favorable for its simple steps and potential to increase the production of L-lysine. The effect of ammonium (NH) concentration on L-lysine biosynthesis was investigated, and the results indicated that the biosynthesis of L-lysine can be promoted in a high NH environment.

L-valine production in Corynebacterium glutamicum based on systematic metabolic engineering: progress and prospects.

L-valine is an essential branched-chain amino acid that cannot be synthesized by the human body and has a wide range of applications in food, medicine and feed. Market demand has stimulated people's interest in the industrial production of L-valine. At present, the mutagenized or engineered Corynebacterium glutamicum is an effective microbial cell factory for producing L-valine.

Redistribution of Intracellular Metabolic Flow in Improves Carbon Atom Economy for High-Yield 2,5-Dimethylpyrazine Production.

2,5-Dimethylpyrazine (2,5-DMP) is an important pharmaceutical intermediate and an important essence. Conventional chemical synthesis methods are often accompanied by toxic substances as by-products, and the biosynthesis efficiency of 2,5-DMP is insufficient for industrial applications. In this study, the and genes were overexpressed to enhance enzymatic and nonenzymatic reactions in metabolic pathways, and was knocked out to block competitive branching carbon flow metabolic pathways.

Improvement of NADPH-dependent P450-mediated biotransformation of 7α,15α-diOH-DHEA from DHEA by a dual cosubstrate-coupled system.

Hydroxylation of DHEA to 7α,15α-diOH-DHEA was catalyzed by NADPH-dependent cytochrome P450 monooxygenase from Colletotrichum lini. By adding coenzyme precursor nicotinic acid, the NADPH/NADP ratio was significantly increased, and the 7α,15α-diOH-DHEA molar conversion was enhanced from 37.37% to 50.

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) production by Haloarchaeon Halogranum amylolyticum.

Haloarchaea is an important group of polyhydroxyalkanoate (PHA)-accumulating organisms. However, few promising haloarchaeal species for economical and efficient PHA production have been reported. Here, we first discovered that Halogranum amylolyticum TNN58 could efficiently accumulate poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with a high 3-hydroxyvalerate (3HV) fraction using glucose as carbon source.

Mutation breeding of high 4-androstene-3,17-dione-producing Mycobacterium neoaurum ZADF-4 by atmospheric and room temperature plasma treatment.

Steroid medication is used extensively in clinical applications and comprises a large and vital part of the pharmaceutical industry. However, the difficulty of separating 4-androstene-3,17-dione (AD) from 1,4-androstadiene-3,17-dione (ADD) restricts the application of the microbial transformation of phytosterols in the industry. A novel atmospheric and room temperature plasma (ARTP) treatment, which employs helium as the working gas, was used to generate Mycobacterium neoaurum mutants producing large amounts of AD.

Enhancement of steroid hydroxylation yield from dehydroepiandrosterone by cyclodextrin complexation technique.

The cyclodextrins (CDs) complexation technique was performed for the enhancement of hydroxylation yield from dehydroepiandrosterone (DHEA) by Colletotrichum lini ST-1. Using DHEA/methyl-β-cyclodextrin (M-β-CD) or DHEA/hydroxypropyl-β-cyclodextrin (HP-β-CD) inclusion complexes as substrate (10g/L), the hydroxylation yields were increased by 14.98% and 20.

Fermentation of biodiesel-derived glycerol by Bacillus amyloliquefaciens: effects of co-substrates on 2,3-butanediol production.

Cultivation in glycerol instead of sugars inhibits 2,3-butanediol (2,3-BD) production by Bacillus amyloliquefaciens. In this study, we report that B. amyloliquefaciens readily produces 2,3-BD from biodiesel-derived glycerol in the presence of beet molasses as a co-substrate.

[Flow-injection chemiluminescence determination of procaterol hydrochloride].

A new flow injection chemiluminescences method for the determination of procaterol hydrochloride has been developed. It is based on the chemiluminescence reaction of procaterol hydrochloride with Ce (IV)-rhodamine B in sulphuric-chlorhydric acid medium and the experimental fact of the enhancement of chemiluminescence by surfactant CTMAB. The concentration of the analyte shows a good linear relationship with the produced luminescence intensity in the range of 2.

[Cloning of the gene encoding a key enzyme involved in production of glycerol in Candida glycerinogenes].

Candida glycerinogenes WL2002-5, an excellent glycerol producer, has been used for industrial scale fermentation of glycerol by an aerobic process. However, our knowledge about glycerol biosynthesis at the molecular level and genetic background of this yeast species lags far behind those of model yeasts such as Saccharomyces cerevisiae et al. In this report, inverse primers, in conjunction with degenerated primers, were used to amplify the NAD+-dependent glycerol 3-phosphate dehydrogenase (GPD) encoding gene from C.

Bioconversion of lovastatin to a novel statin by Amycolatopsis sp.

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase catalyzes the conversion of HMG-CoA to mevalonic acid, which plays a significant role in cholesterol synthesis. Several statins, inhibitors of HMG-CoA reductase, can be synthesized and converted by microorganisms. Among 700 strains obtained from culture collections, one strain could convert lovastatin to a novel statin, wuxistatin.

[Construction of recombinant Saccharomyces cerevisiae producing 1,3-propanediol by one step method].

1,3-Propanediol is one of the most important industrial chemicals for its highly desired properties and its wide applications as a key component of an emerging polymer business. Biological production of 1,3-propanediol has been a novel and competitive way. In our previous job, the gene dahB encoding for glycerol dehydratase from Klebsiella and the gene yqhD encoding for 1,3-propanediol oxidoreductase isoenzyme from E.