RESUMO
To reveal the formation mechanism of fungal community and diversity during the production of Shaoxing Huangjiu, we examined fungal communities in the samples of Linfanjiumu, Maiqu and fermentation mash based on Illumina MiSeq PE300 high-throughput sequencing platform. A total of 136000, 215283, 166150, and 143624 sequences were obtained from the samples of Linfanjiumu, Maiqu, initial mash and mature mash, respectively. After clustering, 32, 133, 107 and 84 OUT (operational taxonomic units) were obtained, respectively. The diversity and richness of fungi were in order of Maiqu > initial mash > mature mash > Linfanjiumu. At the level of phylum, Ascomycota were dominant in all samples. At genus level, Saccharomyces was dominant in Linfanjiumu, Aspergillus was dominant in Maiqu, and Saccharomyces and Aspergillus were the dominant fungi in the initial and mature mash. With the extension of the fermentation time, the proportion of Saccharomyces gradually increased in the mash, while other fungal groups including Aspergillus showed a decreasing trend. According to the results of PCoA analysis and similarity cluster analysis, the structure of fungi community in Linfanjiumu, initial mash and mature mash was much similar, while the fungal resources in Maiqu were quite different from other samples. The analysis of fungal community characteristics in the initial mash showed that the Linfanjiumu and Maiqu affected fungal diversity in Shaoxing Huangjiu. The dominant species of saccharification and fermentation starter (Linfanjiumu and Maiqu) played a leading role in driving community assembly of fermentation fungi.
Assuntos
Ascomicetos , Micobioma , Vinho , Fermentação , Fungos/genética , Sequenciamento de Nucleotídeos em Larga Escala , Vinho/microbiologiaRESUMO
A series of novel 3D 3d-4f heterometallic cluster-based coordination polymers, [Ln4Cr4(µ3-O)4(µ4-O)4(NA)8(H2O)12]·xH2O (Ln = 1-Gd, 2-Tb, 3-Er; HNA = nicotinic acid; x = 13 (1-Gd), 11.33 (2-Tb), 15 (3-Er)), have been successfully synthesized by hydrothermal method using nicotinic acid as bridging ligand. The single-crystal X-ray diffraction (SCXRD) analysis indicated that the basic unit of Ln4Cr4 shows a butterfly-shaped structure. Furthermore, each Ln4Cr4 cluster connects with other four Ln4Cr4 clusters by bridging NA- ligands to form a 3D structure containing interesting 1D honeycomb-shaped coordination nanotubes. The variable temperature magnetic susceptibility measurements of compound 1 revealed that the existence of antiferromagnetic (AF) coupling between the metal ions in the Gd4Cr4 clusters. Field-dependent isothermal magnetization studies displayed that the magnetic entropy change (-ΔSm) value of 1-Gd reached 22.05 J K-1 kg-1.
RESUMO
The use of least-squares support vector machines (LS-SVM) combined with near-infrared (NIR) spectra for prediction of enological parameters and discrimination of rice wine age is proposed. The scores of the first ten principal components (PCs) derived from PC analysis (PCA) and radial basis function (RBF) were used as input feature subset and kernel function of LS-SVM models, respectively. The optimal parameters, the relative weight of the regression error gamma and the kernel parameter sigma 2, were found from grid search and leave-one-out cross-validation. As compared to partial least-squares (PLS) regression, the performance of LS-SVM was slightly better, with higher determination coefficients for validation ( Rval2) and lower root-mean-square error of validation (RMSEP) for alcohol content, titratable acidity, and pH, respectively. When used to discriminate rice wine age, LS-SVM gave better results than discriminant analysis (DA). On the basis of the results, it was concluded that LS-SVM together with NIR spectroscopy was a reliable and accurate method for rice wine quality estimation.
