gamma-aminobutyric acid (GABA) is a four-carbon non-protein amino presented in wide range of organisms. In this study, suppression subtractive hybridization (SSH) library was constructed using roots legume shrub, Caragana intermedia, with the combined treatment 300 mm NaCl and + 10 GABA. We obtained 224 GABA-regulated unique expressed sequence tags (ESTs) including signal transduction, transcriptional regulation, hormone biosynthesis, reactive oxygen species (ROS) polyamine metabolism, etc....

The asymmetric reductive amination of ketones with ammonia using engineered amine dehydrogenases (AmDHs) is a particularly attractive and environmentally friendly method for the synthesis chiral amines. However, one major challenge these AmDHs their limited range accepted substrates. Herein, several were developed through evolution naturally occurring leucine dehydrogenases, which displayed good activity toward aliphatic but restricted catalytic scope short-chain Computational analysis...

Squalene is a high-value antioxidant with many commercial applications. The use of microbial cell factories to produce squalene as an alternative plant and animal extracts could meet increasing market demand. Yarrowia lipolytica excellent host for production due its high levels acetyl-CoA hydrophobic environment. However, the need precise complicated gene editing has hindered industrialization this strain. Herein, rapid construction strain was achieved by enhancing homologous recombination...

The utilization and conversion of one-carbon (C1) feedstocks through biological processes have attracted much interest in building a carbon cycle economy. However, relevant research on the biosynthetic pathway lactic acid (LA) from C1 compounds has not been reported. Herein, three de novo multienzyme synthetic pathways for optically pure racemic LA methanol were successfully engineered using modularized construction optimization approach involving enzyme screening, directed evolution,...

Ketoreductases are tools for the synthesis of chiral alcohols in industry. However, low activity natural enzymes often restricts their use industrial applications. On basis computational analysis and previous reports, two residues (F92 F94) probably affecting ketoreductase CgKR1 were identified. By tuning these residues, CgKR1-F92C/F94W variant was obtained that exhibited higher toward all 28 structurally diverse substrates examined than wild-type enzyme. Among them, 13 have a specific over...

Limonene is an important monoterpene used as a chemical commodity and precursor for producing biofuels, flavor medicinal compounds. In this paper, we engineered Escherichia coli by embedding two exogenous genes encoding limonene synthase (LS) geranyl diphosphate (GPPS) production of limonene. Out 12 E. strains transformed with various plasmids, the best one p15T7-ls-gpps produced titer 4.87 mg/L. order to enhance production, rate-limiting enzymes in endogenous MEP pathway coli,...

Abstract Background β-Nicotinamide mononucleotide (NMN) is the direct precursor of nicotinamide coenzymes such as NAD + and NADP , which are widely applied in industrial biocatalysis especially involving cofactor-dependent oxidoreductases. Moreover, NMN a promising candidate for medical uses since it considered to be beneficial improving health aged people who usually suffer from an insufficient level . To date, various methods have been developed synthesis NMN. Chemical phosphorylation...

A multiscale stability study of foams stabilized by sodium dodecyl sulfate (SDS), dodecylbenzene sulfonate (SDBS), and polyoxyethylene alkylether (AES) was conducted, to investigate the relationship surfactant molecular behavior interfacial monolayer configuration foam film properties. Molecular dynamic (MD) simulations using a full-atom model utilized explore microscopic features air/liquid interface layer. Several parameters such as distribution head groups order degree hydrophobic tails...

A new reductase, CgKR2, with the ability to reduce ethyl 2-oxo-4-phenylbutyrate (OPBE) (R)-2-hydroxy-4-phenylbutyrate ((R)-HPBE), an important chiral precursor for angiotensin-converting enzyme (ACE) inhibitors, was discovered. For first time, (R)-HPBE >99% ee produced via bioreduction of OPBE at 1 M without external addition cofactors. The space-time yield (700 g·L–1·d–1) 27 times higher than highest record.

In this paper, ultrastable aqueous foam stabilized by a kind of flexible connecting bipolar-headed surfactant alkyl polyoxyethylene sulfate (AE3S) with coexisting Mg(2+) was reported. Detailed molecular behaviors AE3S in film divalent cationic Ca(2+) or were investigated dynamic simulation, comparing the traditional sodium dodecyl (SDS), to find out how microcharacter and array behavior molecules determined interaction effect stability. It found that obtained cooperation magnesium ions...

Abstract In order to search for oxidoreductases suitable the preparation of methyl ( R )‐ o ‐chloromandelate [( )‐CMM], key intermediate clopidogrel, homologous proteins Gre2p were expressed in Escherichia coli , among which CgKR1 showed most satisfactory activity and stereoselectivity towards ‐chlorobenzoylformate (CBFM). Using crude enzyme glucose dehydrogenase (GDH), as much 300 g⋅L −1 CBFM was almost stoichiometrically converted )‐CMM with excellent enantiomeric excess (98.7% ee ). More...

Dehydrogenases are widely employed as biocatalysts for the production of optically pure chemicals under mild conditions. Most dehydrogenases nicotinamide cofactor (NADPH or NADH)-dependent oxidoreductases. 7β-Hydroxysteroid dehydrogenase (7β-HSDH) is a key enzyme biochemical synthesis ursodeoxycholic acid (UDCA). To date, all reported 7β-HSDHs strictly NADPH-dependent enzymes. However, compared with NADPH, NADH much more economical, making it preferential synthetic applications...

(-)-α-Bisabolol, a monocyclic susquiterpene alcohol, has been widely used in the fields of food, medicine, and biofuel. Recently, rapid development synthetic biology offered sustainable route for production (-)-α-bisabolol by microbial cell factories. Even though efficient biosynthesis achieved Escherichia coli with highest titer 23.4 g/L, possible infection risk bacteriophage makes E. unsuitable to act as most robust chassis. Herein, we optimized MVA pathway Komagataella phaffii fused...

Abstract A β‐ketoacyl‐ACP reductase (FabG) gene from Bacillus sp. ECU0013 was heterologously overexpressed in Escherichia coli and the encoded protein purified to homogeneity. The recombinant could reduce a broad spectrum of prochiral ketones including aromatic keto esters showed highest activity asymmetric reduction ethyl 2‐oxo‐4‐phenylbutyrate (OPBE). Using E. cells coexpressing both FabG glucose dehydrogenase (GDH) genes, as much 620 g⋅L −1 OPBE almost stoichiometrically converted ( S...

Ursodeoxycholic acid (UDCA) is the main active ingredient of natural bear bile powder with multiple pharmacological functions. 7β-Hydroxysteroid dehydrogenase (HSDH) a key biocatalyst for synthesis UDCA. However, all 7β-HSDHs reported commonly suffer from poor activity and thermostability, resulting in limited productivity In this study, multiobjective directed evolution (MODE) strategy was proposed applied to improve activity, pH optimum 7β-HSDH. The best variant (V3-1) showed specific...

Glucose dehydrogenase (GDH) is a general tool for driving nicotinamide (NAD(P)H) regeneration in synthetic biochemistry. An increasing number of bioreactions are carried out media containing high amounts organic cosolvents or hydrophobic substrates/products, which often denature native enzymes, including those cofactor regeneration. In this work, we attempted to improve the chemical stability Bacillus megaterium GDH (BmGDHM0 ) presence large 1-phenylethanol by directed evolution. Among...

A carbonyl reductase gene (yueD) from Bacillus sp. ECU0013 was heterologously overexpressed in Escherichia coli, and the encoded protein (BYueD) purified to homogeneity characterized. The NADPH-dependent showed a broad substrate spectrum towards different aromatic ketones, α- β-ketoesters. Although enantioselectivity high moderate for reduction of α-ketoesters, all tested β-ketoesters ketones were reduced corresponding chiral alcohols enantiomerically pure forms. Furthermore, practical...

Carbonic anhydrase (CA, EC 4.2.1.1), an ancient enzyme and the fastest among many enzymes, is a useful biocatalyst for carbon capture use storage (CCUS). The of alkaline buffers high temperatures are favorable biomineralization. Hence, stability CA under such harsh conditions extremely important its practical application. Herein, we report new thermostable alkaline-tolerant α-CA (designated as LdCA), with only 26 % identity to bovine (BCA), which was identified by genome mining from...

Ursodeoxycholic acid (UDCA) is an effective drug for the treatment of hepatitis. In this study, 7α-hydroxysteroid dehydrogenase (7α-HSDH) and lactate (LDH), as well 7β-hydroxysteroid (7β-HSDH) glucose (GDH), were co-immobilized onto epoxy-functionalized resin (ES-103) to catalyze synthesis UDCA from chenodeoxycholic (CDCA). Through optimizing immobilization pH, time, loading ratio enzymes resin, specific activities immobilized LDH-7αHSDH@ES-103 7βHSDH-GDH@ES-103 43.2 25.8 U g-1 ,...

To improve the fermentation production of transglutaminase (TGase) from Streptomyces mobaraensis for applications in food industry, atmospheric and room-temperature plasma (ARTP) mutagenesis was applied to breed S. mutants with increased TGase production. After eight rounds iterative ARTP mutagenesis, four genetically stable mutants, Sm5-V1, Sm6-V13, Sm2-V10, Sm7-V12, were identified, which showed by 27, 24, 19%, respectively. The best mutant Sm5-V1 exhibited a maximum activity 5.85 U/mL...