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BACKGROUND: Nicotinamide mononucleotide (NMN), a key intermediate of nicotinamide adenine dinucleotide, plays an important in anti‐aging and disease. Lactococcus lactis, an important probiotic lactic acid bacteria (LAB), has shown great potential for the biosynthesis of NMN, which will significantly affect the probiotic effects of the dairy products. RESULTS: We used the CRISPR/nCas9 technique to knockout nadR gene of L. lactis NZ9000 to enhance the accumulation of NMN by 61%. The nadE* gene from Francisella tularensis with codon optimization was heterologous in L. lactis NZ9000ΔnadR and has a positive effect on NMN production. Combined with optimization of the concentration of substrate nicotinamide, a final intracellular NMN titer was 2289 μmol L–1 mg–1 with 10 g L–1 nicotinamide supplement, which was 5.7‐fold higher than that of the control. The transcription levels of key genes (pncA, nadD and prs1) involved in NMN biosynthesis were up‐regulated by more than two‐fold, indicating that the increase of NMN titer was attributed to FtnadE* heterologous expression. CONCLUSION: Our study provides a better understanding of the NMN biosynthesis pathway in L. lactis, and can facilitate NMN production in LAB via synthetic biology approaches. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The rational design and synthesis of hierarchical three-dimensional nanostructures with diversified compositions and fascinating morphologies can provide abundant choices and enhanced probability for applications in the energy storage field. Herein, we report an effective, metal catalyst- or surfactant-free approach for the controlled growth of hierarchical one-dimensional (1D)/two-dimensional (2D) nanostructures. The quasi-paralleled and interlaced nanosheet arrays of NiMn layered double hydroxides are grown on KCu7S4 microwires with a quasi-one-dimensional channel. The supersaturation of the system and screw dislocation-driven growth pattern of 2D materials could be key factors in determining the structure of the nanosheets arrays of NiMn LDHs. The electrochemical investigation shows that the KCu7S4@NiMn LDHs have a significantly enhanced specific capacitance (879 F g−1 at 1 mV s−1, 733.8 F g−1 at 1 A g−1) and rate capability (76.9% retention at 30 A g−1) that far exceed those of the reported individual KCu7S4 electrodes. A hybrid supercapacitor based on KCu7S4@NiMn LDH//activated graphene electrode also presents good cycle stability (an 84.8% capacitance retention after 16 000 cycles). The outstanding supercapacitor performance forebode the enormous potential of KCu7S4@NiMn LDH composites in electrochemical properties. [ABSTRACT FROM AUTHOR]

High-fat diets may promote growth, partly through their protein-sparing effects. However, high-fat diets often lead to excessive fat deposition, which may have a negative impact on fish such as poor growth and suppressive immune. Therefore, this study investigated the effects of a fat-rich diet on the mechanisms of fat deposition in the liver. Three-hundred blunt snout bream (Megalobrama amblycephala) juveniles (initial mass 18.00±0.05 g) were fed with one of two diets (5% or 15% fat) for 8 weeks. β-Oxidation capacity and regulation of rate-limiting enzymes were assessed. Large fat droplets were present in hepatocytes of fish fed the high-fat diet. This observation is thought to be largely owing to the reduced capacity for mitochondrial and peroxisomal β-oxidation in the livers of fish fed the high-fat diet, as well as the decreased activities of carnitine palmitoyltransferase (CPT) I and acyl-CoA oxidase (ACO), which are enzymes involved in fatty-acid metabolism. Study of CPT I kinetics showed that CPT I had a low affinity for its substrates and a low catalytic efficiency in fish fed the high-fat diet. Expression of both CPT I and ACO was significantly down-regulated in fish fed the high-fat diet. Moreover, the fatty-acid composition of the mitochondrial membrane varied between the two groups. In conclusion, the attenuated β-oxidation capacity observed in fish fed a high-fat diet is proposed to be owing to decreased activity and/or catalytic efficiency of the rate-limiting enzymes CPT I and ACO, via both genetic and non-genetic mechanisms. [ABSTRACT FROM AUTHOR]

Objective: To study the volatile constituents from peel of Aquilaria sinensis (Lour.) Gilg. and its anti-tumor activity., Methods: The volatile components from peel of A. sinensis were extracted by chloroform and analysed by the GC-MS technique. Assay the peel extract of A. sinensis on MCF-7 cell proliferation using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) method., Results: GC-MS gave 131 peaks and 28 compounds have been identified. The contents of the benzene compounds accounted 7.79% of the volatile components, the esquiterpenes accounted 5.44%, and the relative content of fatty acids accounted 3.08%. In addition, two 2-(2-phenylethyl)-color ketones and a chromone component were detected, and the total relative content accounted 12.3%. The inhibition rate of human breast cancer cells reached 99. 6% when the concentration was 500 microg/mL., Conclusion: The volatile components from peel of A. sinensis were analysed and a large number of characteristic elements of A. sinensis were detected for the first time. The chloroform extract from peel of A. sinensis significantly inhibited the proliferation of human breast cancer cells.

The title compound, C(9)H(11)NO(4), is an inter-mediate for dyes and drugs. The O-C-C-O chain adopts a synclinal conformation. The crystal structure is stabilized by C-H⋯O hydrogen bonds.