Transcriptomic-metabolomic analysis reveals the effect of copper toxicity on fermentation properties in Saccharomyces cerevisiae.

Copper is one of the unavoidable heavy metals in wine production. In this study, the effects on fermentation performance and physiological metabolism of Saccharomyces cerevisiae under copper stress were investigated. EC1118 was the most copper-resistant among the six strains. The ethanol accumulation of EC1118 was 26.16-20 mg/L Cu2+, which was 1.90-3.15 times higher than that of other strains. The fermentation rate was significantly reduced by copper, and the inhibition was relieved after 4-10 days of adjustment. Metabolomic-transcriptomic analysis revealed that amino acid and nucleotide had the highest number of downregulated and upregulated differentially expressed metabolites, respectively. The metabolism of fructose and mannose was quickly affected, which then triggered the metabolism of galactose in copper stress. Pathways such as oxidative and organic acid metabolic processes were significantly affected in the early time, resulting in a significant decrease in the amount of carboxylic acids. The pathways related to protein synthesis and metabolism under copper stress, such as translation and peptide biosynthetic process, was also significantly affected. In conclusion, this study analyzed the metabolite-gene interaction network and molecular response during the alcohol fermentation of S. cerevisiae under copper stress, providing theoretical basis for addressing the influence of copper stress in wine production.

The haplotype-resolved T2T genome of teinturier cultivar Yan73 reveals the genetic basis of anthocyanin biosynthesis in grapes.

Teinturier grapes are characterized by the typical accumulation of anthocyanins in grape skin, flesh, and vegetative tissues, endowing them with high utility value in red wine blending and nutrient-enriched foods developing. However, due to the lack of genome information, the mechanism involved in regulating teinturier grape coloring has not yet been elucidated and their genetic utilization research is still insufficient. Here, the cultivar 'Yan73' was used for assembling the telomere-to-telomere (T2T) genome of teinturier grapes by combining the High Fidelity (HiFi)， Hi-C and ultralong Oxford Nanopore Technologies (ONT) reads. Two haplotype genomes were assembled, at the sizes of 501.68 Mb and 493.38 Mb, respectively. In the haplotype 1 genome, the transposable elements (TEs) contained 32.77% of long terminal repeats (LTRs), while in the haplotype 2 genome, 31.53% of LTRs were detected in TEs. Furthermore, obvious inversions were identified in chromosome 18 between the two haplotypes. Transcriptome profiling suggested that the gene expression patterns in 'Cabernet Sauvignon' and 'Yan73' were diverse depending on tissues, developmental stages, and varieties. The transcription program of genes in the anthocyanins biosynthesis pathway between the two cultivars exhibited high similarity in different tissues and developmental stages, whereas the expression levels of numerous genes showed significant differences. Compared with other genes, the expression levels of VvMYBA1 and VvUFGT4 in all samples, VvCHS2 except in young shoots and VvPAL9 except in the E-L23 stage of 'Yan73' were higher than those of 'Cabernet Sauvignon'. Further sequence alignments revealed potential variant gene loci and structure variations of anthocyanins biosynthesis related genes and a 816 bp sequence insertion was found in the promoter of VvMYBA1 of 'Yan73' haplotype 2 genome. The 'Yan73' T2T genome assembly and comparative analysis provided valuable foundations for further revealing the coloring mechanism of teinturier grapes and the genetic improvement of grape coloring traits.

Cesium immobilization by K-struvite crystal in aqueous solution: Ab initio calculations and experiments.

The use of immobilization methods to treat radioactive nuclear waste liquid is one of the most effective ways for preventing radioactive contamination. Understanding the solidification matrix for the immobilization behavior of radioactive ions is ​​an important issue. In this work, ab initio calculation was used to study the solidification mechanism of Cs+ in K-struvite crystal in the aqueous solution. Corresponding experiments were carried out and analyzed by XRF1, XPS2, AAS3, FI-IR4, SEM5, EDS6 and XRD7 . This work proposed a calculation method for the ΔEaq8 . By analyzing ΔEaq, the tendency of Cs+ to occupy the K site in K-struvite crystal is remarkable. Furthermore, in-depth first-principles calculations show that this immobilization behavior is related to the electronic structures of K-struvite and Cs-struvite9, and they together with the interaction of cation and aqueous solution determine the energy change of the process. This work provides a basic perspective for the study of magnesium phosphate potassium cement solidified nuclides, which is convenient for judging the solidification of other nuclide ions, thereby designing K-struvite cement for solidified nuclide. This method is also readily extended to other studies of the chemical immobilization of any crystal in the solution to any other ions.

Cement-Based Materials Containing Graphene Oxide and Polyvinyl Alcohol Fiber: Mechanical Properties, Durability, and Microstructure.

The influence of graphene oxide (GO) and polyvinyl alcohol (PVA) fiber on the mechanical performance, durability, and microstructure of cement-based materials was investigated in this study. The results revealed that compared with a control sample, the mechanical strength and durability of cement-based materials were significantly improved by adding PVA fiber and GO. The compressive and flexural strength at 28 d were increased by 30.2% and 39.3%, respectively. The chloride migration coefficient at 28 d was reduced from 7.3 × 10-12 m²/s to 4.3 × 10-12 m²/s. Under a sulfate corrosion condition for 135 d, the compressive and flexural strength still showed a 13.9% and 12.3% gain, respectively. Furthermore, from the Mercury Intrusion Porosimetry (MIP) test, with the incorporation of GO, the cumulative porosity decreased from more than 0.13 cm³/g to about 0.03 cm³/g, and the proportion of large capillary pores reduced from around 80% to 30% and that of medium capillary pores increased from approximately 20% to 50%. Scanning electron microscope (SEM) images showed a significant amount of hydration products adhering to the surface of PVA fiber in the GO and PVA fiber modified sample. The addition of GO coupling with PVA fiber in cement-based materials could promote hydration of cement, refine the microstructure, and significantly improve mechanical strength and durability.

Passively Q-switched Yb:YAG laser based on a MoSe2 saturable absorber.

A MoSe2 nanosheets-based saturable absorber (SA) was fabricated successfully by the liquid-phase exfoliation method. A passively Q-switched crystalline Yb:YAG laser was realized with the MoSe2 SA inserted inside the cavity. The shortest pulses at a wavelength of 1049 nm with a duration of 250 ns, maximum repetition rate of 181 kHz, and an average output power of 158 mW were emitted, corresponding to a maximum pulse energy of 0.87 µJ. To the best of our knowledge, this is the first experimental demonstration of the nonlinear absorption property of MoSe2 nanoplatelets in a crystalline Yb-doped solid-state laser, which also proves the great potential of the MoSe2 SA as an optical modulator in the 1 µm spectral region.

Characterization of aroma compounds in Chinese bayberry (Myrica rubra Sieb. et Zucc.) by gas chromatography mass spectrometry (GC-MS) and olfactometry (GC-O).

The aroma-active compounds in Chinese bayberry were identified using gas chromatography-olfactometry (GC-O) and GC-mass spectrometry techniques. The volatile compounds were extracted using Liquid-liquid extraction, solvent-assisted flavor evaporation and headspace solid-phase microextraction (HS-SPME), respectively. On the basis of odor intensity, the most important aroma compounds in Chinese bayberry samples were caryophyllene, menthol, 4-terpineol, linalool oxide, linalool, benzyl alcohol, α-methylbenzyl alcohol, ß-phenylethanol, 3-methylbutanoic acid and acetic acid, and so on. Moreover, HS-SPME technique was employed to investigate the aroma compounds among immature and mature waxberry fruits. The results showed that terpenes (for example, ß-caryophyllene) was predominant and its concentration represented over 89.9% of the overall compounds, and alcohols, aldehydes, ketones, esters, acids, and others were typically present in lesser amounts. Finally, principal component analysis revealed that there was also significant difference between immature and mature waxberry fruits.

Identification and quantification of impact aroma compounds in 4 nonfloral Vitis vinifera varieties grapes.

The aroma compounds in grapes of Cabernet gernischt, Cabernet sauvignon, Cabernet franc, and Merlot have been studied by gas chromatography-olfactometry (GC-O). The GC-O study revealed the presence of 58 aroma compounds in which 53 odorants were identified. The most significant odor active volatiles in 4 grape berries were beta-damascenone, hexanal, (Z)-3-hexen-1-ol, (E,Z)-2,6-nonadienal, beta-ionone, and unknown (RI = 1612). The quantification of volatile aroma compounds in grapes was developed using headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The influences of SPME fiber, extracting temperature, and time on the extraction of volatile compounds in grape were investigated. The aroma compounds in 4 grapes were quantified. According to the odor activity values (OAVs), (E,Z)-2,6-nonadienal (OAV from 334 to 777), beta-damascenone (OAV 245-790), beta-ionone (OAV 97-193), and acetic acid (OAV 7-165) had comparatively high OVA values.

[Analysis of free terpenoids in four Vitis vinifera varieties using solvent assisted flavour evaporation and gas chromatography-tadem mass spectrometry].

The free terpenoids in four Vitis vinifera varieties were studied by solvent assisted flavour evaporation (SAFE) and gas chromatography-tadem mass spectrometry (GC-MS/MS). The compounds of the grapes were extracted with vibrating extraction at constant temperature, and then the non-volatiles were removed by SAFE. The volatile compounds were concentrated with a stream of nitrogen and analyzed by GC-MS/MS. The temperature of cycle water and flow rate of the sample were optimized in SAFE procedure. In the four varieties of grapes, a total of 30 terpenoids were identified by mass spectral data from NIST05a and Kovats retention indices of the standards (RI(S)) or from the literature (RI(L)), including 10 monoterpenoids, 18 sesquiterpenoids, 1 diterpenoid, and 1 triterpenoid. Twenty-eight terpenoids were detected in Cabernet Gernischt, and 16, 1.7, and 16 in Merlot, Cabernet Sauvignon, and Cabernet Fanc, respectively. A total of 17 sesquiterpenoids were identified in Cabernet Gernischt, and it was the richest among the four grapes. According to semi-quantitative method, the concentration of monoterpenoids in Cabernet Sauvignon was the highest among the four grapes, whereas the concentration of sesquiterpenoids in Cabernet Gernischt was the highest. The results showed that this method can be used to identify and quantify the free terpenoids in grapes.