Flavor compound structural analysis during the douchi fermentation process.

(a) PCoA of flavor components generated during douchi fermentation. Green box indicates the flavor components, blue triangle indicates group 1, and red triangle denotes group 2. The grouping mode is based on Hellinger distances with 97% similarity. (b) HCA of the flavor components generated during douchi fermentation.</p

Flavor components generated during douchi fermentation.

Flavor components generated during douchi fermentation.</p

Table_1_Biological potential of Bacillus subtilis BS45 to inhibit the growth of Fusarium graminearum through oxidative damage and perturbing related protein synthesis.DOCX

Fusarium root rot (FRR) caused by Fusarium graminearum poses a threat to global food security. Biological control is a promising control strategy for FRR. In this study, antagonistic bacteria were obtained using an in-vitro dual culture bioassay with F. graminearum. Molecular identification of the bacteria based on the 16S rDNA gene and whole genome revealed that the species belonged to the genus Bacillus. We evaluated the strain BS45 for its mechanism against phytopathogenic fungi and its biocontrol potential against FRR caused by F. graminearum. A methanol extract of BS45 caused swelling of the hyphal cells and the inhibition of conidial germination. The cell membrane was damaged and the macromolecular material leaked out of cells. In addition, the mycelial reactive oxygen species level increased, mitochondrial membrane potential decreased, oxidative stress-related gene expression level increased and oxygen-scavenging enzyme activity changed. In conclusion, the methanol extract of BS45 induced hyphal cell death through oxidative damage. A transcriptome analysis showed that differentially expressed genes were significantly enriched in ribosome function and various amino acid transport pathways, and the protein contents in cells were affected by the methanol extract of BS45, indicating that it interfered with mycelial protein synthesis. In terms of biocontrol capacity, the biomass of wheat seedlings treated with the bacteria increased, and the BS45 strain significantly inhibited the incidence of FRR disease in greenhouse tests. Therefore, strain BS45 and its metabolites are promising candidates for the biological control of F. graminearum and its related root rot diseases.</p

Correlation between microbiota and flavor components in the douchi fermentation process, evaluated with the O2PLS method.

(a) VIP(pred) plot of the microbiota correlated strongly with flavor components (VIP(pred) > 1.0). (b) Network of correlations between microbiota and flavor components during douchi fermentation. The left-side circle represents genera (|p| > 0.7); the right-side circle denotes flavor components; red line between microbiota and flavor components indicates positive correlation (p > 0.7); and blue line shows negative correlation (p < −0.7). (c) The details of the microbiota and the flavor components.</p

Relative abundances of bacteria at the phylum (a) and genus (b) levels during douchi fermentation.

Relative abundances of bacteria at the phylum (a) and genus (b) levels during douchi fermentation.</p

Mechanical tests of AF tissues.

<p>(A–B) The picture of a paraffin-embedded AF sample and a schematic showing how the testing regions and points were selected. Note NP was removed from the IVD. (C) The pre-test and post-test images of a sample under nanoindentation test, from which an imprint is clearly seen (shown by the arrowhead). (D) The storage moduli of oAF, mAF and iAF measured using nanoindentation at different frequencies. (E) The Young’ moduli of oAF, mAF and iAF measured using tensile test. All data are presented as mean±SD. Asterisk (*) indicates significant difference between groups (<i>p</i><0.01, n≥10).</p

Pictures of an IVD and its sections.

<p>(A) A whole rabbit IVD. (B) With the NP (1) being removed, the AF was separated into three equal parts, i.e., iAF (2), mAF (3) and oAF (4), respectively.</p

CTFM measurement of AF cells.

<p>(A) CTFM for measuring CTFs of iAFC, mAFC and oAFC. <i>a–c</i>, primary cells from each region; <i>d–f</i>, the substrate displacement fields; <i>g–i</i>, the CTF maps. (B–C) CTFs and spread areas of iAFC, mAFC and oAFC, respectively. All data are presented as mean±SD. Asterisk (*) indicates significant difference between groups (<i>p</i><0.05, n≥30).</p

Bacterial structural analysis during the douchi fermentation process.

(a) PCoA of the microbial communities, PC1 variance = 56.88%, PC2 variance = 31.82%. (b) Cluster analysis of the bacterial microbiota involved in the douchi fermentation process. Green indicates samples belonging to group 1 and red indicates samples belonging to group 2.</p

Regional Variations in the Cellular, Biochemical, and Biomechanical Characteristics of Rabbit Annulus Fibrosus

<div><p>Tissue engineering of annulus fibrosus (AF), the essential load-bearing disc component, remains challenging due to the intrinsic heterogeneity of AF tissue. In order to provide a set of characterization data of AF tissue, which serve as the benchmark for constructing tissue engineered AF, we analyzed tissues and cells from various radial zones of AF, i.e., inner AF (iAF), middle AF (mAF), and outer AF (oAF), using a rabbit model. We found that a radial gradient in the cellular, biochemical, and biomechanical characteristics of rabbit AF existed. Specifically, the iAF cells (iAFCs) had the highest expression of collagen-II and aggrecan genes, while oAF cells (oAFCs) had the highest collagen-I gene expression. The contents of DNA, total collagen and collagen-I sequentially increased from iAF, mAF to oAF, while glycosaminoglycan (GAG) and collagen-II levels decreased. The cell traction forces of primary AFCs gradually decreased from iAFCs, mAFCs to oAFCs, being 336.6±155.3, 199.0±158.8, and 123.8±76.1 Pa, respectively. The storage moduli of iAF, mAF, and oAF were 0.032±0.002, 2.121±0.656, and 4.130±0.159 MPa, respectively. These measurements have established a set of reference data for functional evaluation of the efficacy of AF tissue engineering strategies using a convenient and cost-effective rabbit model, the findings of which may be further translated to human research.</p></div