Effect of bacillus subtilis strain Z15 secondary metabolites on immune function in mice.

BACKGROUND: Previous studies have shown that secondary metabolites of Bacillus subtilis strain Z15 (BS-Z15) are effective in treating fungal infections in mice. To evaluate whether it also modulates immune function in mice to exert antifungal effects, we investigated the effect of BS-Z15 secondary metabolites on both the innate and adaptive immune functions of mice, and explored its molecular mechanism through blood transcriptome analysis. RESULTS: The study showed that BS-Z15 secondary metabolites increased the number of monocytes and platelets in the blood, improved natural killer (NK) cell activity and phagocytosis of monocytes-macrophages, increased the conversion rate of lymphocytes in the spleen, the number of T lymphocytes and the antibody production capacity of mice, and increased the levels of Interferon gamma (IFN-γ), Interleukin-6 (IL-6), Immunoglobulin G (IgG) and Immunoglobulin M (IgM) in plasma. The blood transcriptome analysis revealed 608 differentially expressed genes following treatment with BS-Z15 secondary metabolites, all of which were significantly enriched in the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) terms for immune-related entries and pathways such as Tumor Necrosis Factor (TNF) and Toll-like receptor (TLR) signaling pathways, and upregulated expression levels of immune-related genes such as Complement 1q B chain (C1qb), Complement 4B (C4b), Tetracyclin Resistant (TCR) and Regulatory Factor X, 5 (RFX5). CONCLUSIONS: BS-Z15 secondary metabolites were shown to enhance innate and adaptive immune function in mice, laying a theoretical foundation for its development and application in the field of immunity.

Effects of Bacillus subtilis BS-Z15 on Intestinal Microbiota Structure and Body Weight Gain in Mice.

In our previous study, we identified a metabolite of Bacillus subtilis BS-Z15 (a strain with probiotic characteristics) that could improve immunity in mice. In the present study, we examined the effects of B. subtilis BS-Z15 and its metabolites on body weight gain and the intestinal microbiota of mice. Sixty 25-day-old male Kunming white mice were selected and randomly divided into four groups: control group (A), daily saline gavage; B. subtilis-treated group (B), single gavage (1 × 109 CFU/time/animal/day); group D, 14 consecutive gavages (1 × 109 CFU/time/animal/day); and B. subtilis metabolite-treated group (E), 30 consecutive gavages (90 mg kg-1/time/animal/day). High-throughput sequencing technology was used to analyze intergroup differences in the mouse intestinal microbiota. The results showed that the three treated groups had significantly slower body weight gain compared with the control group, which lasted until the 45 days (P < 0.05), and the daily food intake of the treated mice was higher (P < 0.05). The intestinal microbiota structure of the mice in the treated groups was significantly altered compared with that in the control group, suggesting that B. subtilis BS-Z15 may regulate the weight gain of animals by affecting their intestinal bacterial composition. After stopping the gavage of B. subtilis BS-Z15, the abundance of this strain in the small intestine of the mice gradually decreased and its presence was undetectable at 45 days, indicating that B. subtilis BS-Z15 could not colonize the intestine of these mice. These findings suggest that B. subtilis BS-Z15 may regulate intestinal microbiota through its metabolites to reduce weight gain.

[Chemical structure characteristics of organic carbon in saline soil aggregates under straw returning condition]. / 秸秆还田条件下盐渍土团聚体中有机碳化学结构特征.

We examined the regularity of distribution and chemical structure characteristics of organic carbon in soda alkaline fluvo-aquic soil aggregates after straw returning. We set up six different straw returning treatments in 2020, including 0 (CK), 2100 (ST1), 4200 (ST2), 6300 (ST3), 8400 (ST4) and 10500 kg·hm-2(full straw returning, ST5). We measured organic carbon (OC) content and infrared spectroscopy characteristics of aggregates and internal different components through physical fractionation method and infrared spectroscopy technology. The results showed that: 1) the OC content of soil and all aggregates increased with the increasing amount of returned straw; 2) different straw returning treatments significantly increased the content of light organic carbon (LOC) in 53-250 µm aggregates. Compared with CK, ST3 and ST4 treatments significantly increased the content of mineral-bound organic carbon (MOC) in 250-2000 µm aggregates and the content of fine particulate organic carbon (fPOC) in 53-250 µm aggregates. The OC content of different components in aggregates followed the order of LOC>MOC>POC. The fPOC content in 250-2000 µm aggregates was higher than that of coarse particulate organic carbon (cPOC); 3) the results of principal component analysis showed that OC chemical structure of different components in aggregates was seldom affected by the straw returning, but was mainly affected by particle size; 4) the OCs in >250 µm aggregates were mainly derived from aromatic carbon and polysaccharides. The OCs in 53-250 µm aggregates were mainly derived from carbohydrates, such as monosaccharides and polysaccharides, while the OC in <53 µm aggregates was mainly derived from aliphatic carbon, alkyl carbon, aromatic carbon and phenolic alcohols. Within different aggregates, LOC was mainly derived from aliphatic carbon, aromatic carbon and phenolic alcohols. Particulate organic carbon (POC) was mainly derived from carbohydrates. MOC was mainly derived from alkyl carbon. In summary, straw returning increased organic carbon content in soil aggregates in short term, but did not alter organic carbon chemical structure. The organic carbon chemical structures of the same particle size fractions in different aggregates were similar. The organic carbon content increased with the decreases of particle size, and the chemical structure tended to be stable. Therefore, straw returning promoted the fixation of organic carbon by saline soil aggregates in short term, but did not change their chemistry structural characteristics, indicating that the location and protection degree of soil organic carbon in aggregates were the main factors affecting the chemical structure of organic carbon.

The complete chloroplast genome sequence of Lepidium perfoliatum L.

This study was based on the collection of the complete genome of Lepidium perfoliatum chloroplast (cp). The full cp genome is 154,264 bp long, containing 130 genes, in which 8 genes are specified for ribosomal RNA (rRNA), while 85 and 37 genes for protein-coding and transfer RNA (tRNA) respectively. Phylogenetic analyss revealed the closed cluster of Lepidium perfoliatum with other Lepidium species such as Lepidium apetalum, Lepidium sativum, Lepidium meyenii and Lepidium virginicum, which helps for the evaluation of how Lepidium perfoliatum is phylogenetically related to other species.

Genome sequencing and functional annotation of Bacillus sp. strain BS-Z15 isolated from cotton rhizosphere soil having antagonistic activity against Verticillium dahliae.

In the present study, antagonistic activity of bacterial strain BS-Z15, was evaluated against Verticillium dahlia. The fermented broth of BS-Z15 inhibited the growth of Verticillium dahliae. The genome of strain BS-Z15 had a total size of 4,068,702 base pairs and contained 4318 genes, of which 4196 are coding sequences and 122 are non-coding RNA. Among these genes, nine genomic islands, 86 tRNAs, 13 sRNAs, and one prophage was determined. With the help of annotation databases, most unigene functions were identified. At the same time, genomic comparison between BS-Z15 and 12 Bacillus members showed that the genes of BS-Z15 were closely related to the Bacillus group, and were conserved between the two groups, including most of the genes associated with fungal antagonism. BS-Z15 contains genes involved in a variety of antagonistic mechanisms, including genes encoding or synthesizing mycosubtilin, chitinases (but not CHIA and CHIB), glycoside hydrolases, iron nutrients, and antibiosis. However, it only contained the complete mycosubtilin- and bacilibactin-related operators in the reported main antifungal gene cluster of B. subtilis. Mycosubtilin and bacilibactin may be the main active antifungal substance. Besides, some genes could encode products related to biofilm production, which may be related to the colonization ability of the strain in plant rhizospheres. The complete genome of B. subtilis BS-Z15 provided new insights into the potential metabolites it produces related to its biocontrol activity.

[Disorder of copper homeostasis induced by lead exposure among mice and intervention effect of quercetin].

OBJECTIVE: To investigate the effect of lead exposure on copper and copper metalloenzyme and the intervention effect of quercetin. METHODS: Twenty-four specific pathogen-free male Sprague-Dawley rats of good health were randomly divided into control group (n = 8), lead acetate group (n = 8), and lead acetate + quercetin group (n = 8). The rats in lead acetate group were poisoned by drinking water with 1 g/L lead acetate for 8 weeks, while the rats in control group were fed by drinking water with sodium acetate of the same volume for 8 weeks; the rats in lead acetate+quercetin group were intraperitoneally injected with quercetin (30 mg × kg-1 × d-1) for 8 weeks while drinking water with lead acetate. The Morris water maze was used to test the learning and memory abilities of rats. The lead and copper levels in the serum, hippocampus, cortex, and bone were measured by graphite furnace atomic absorption spectrometry. The level of advanced glycation end products, activity of Cu/Zn superoxide dismutase (SOD), and content and activity of ceruloplasmin (CP) in the hippocampus and serum were measured using a test kit. HE staining was performed to observe the pathological changes in the hippocampus. RESULTS: The Morris water maze test showed that the latency in lead acetate group (52.50±12.04 s) was significantly longer than that in control group (28.08±7.31 s) (P<0.05), and the number of platform crossings was significantly lower in the lead acetate group than in the control group. Compared with those in the control group, the lead levels in the cortex and hippocampus in lead acetate group increased 2.72-fold and 3.79-fold, and the copper in the cortex and hippocampus, and serum free copper levels in lead acetate group increased 1.15-fold, 1.48-fold, and 6.44-fold. Compared with the control group, the lead acetate group had a lower content of CP in the hippocampus (1.23±0.40 U/mg provs0.78±0.08 U/mg pro) and 31.81%and 19.49%decreases in CP content and Cu/Zn SOD activity. Free copper level in serum was positively correlated with the latency and lead levels in the serum, cortex, and hippocampus. The escape latency of rats in lead acetate + quercetin group was decreased by 42.15% (P<0.05). The lead levels in the cortex and hippocampus in lead acetate + quercetin group (0.246 ± 0.58 µg/g and 0.202±0.049 µg/g) were significantly lower than those in lead acetate group (0.391±0.49 µg/g and 0.546±0.120 µg/g), but the free copper and copper levels in the hippocampus and cortex were not significantly reduced. The lead acetate + quercetin group had higher Cu/Zn SOD activity and CP content in the hippocampus than the lead acetate group (P < 0.05). The light microscope observation showed that the number of cells in the hippocampus was reduced with disordered arrangement in the lead acetate group; with quercetin intervention, the hippocampus damage was reduced. CONCLUSION: Lead exposure results in disorder of copper homeostasis, while quercetin may alleviate the damage induced by lead to some extent.

Expression of PINCH protein in gliomas and its clinicopathological significance.

OBJECTIVES: Particularly interesting new cysteine-histidine-rich protein (PINCH), as a LIM domain adapter protein, functions in the integrin and growth factor signal transduction pathway, and is upregulated in tumor-associated stroma in several types of cancers. However, no study of PINCH has been carried out in gliomas, therefore we examined PINCH expression in gliomas and its clinicopathological significance. METHODS: PINCH expression was immunohistochemically examined in 82 gliomas, along with 26 matched adjacent normal brain samples and 10 recurred gliomas. RESULTS: PINCH was strongly expressed in the primary (35%, p = 0.0001) or recurred tumors (40%, p = 0.004) and weak in normal brain tissue. PINCH expression was significantly increased in high-grade gliomas (55 vs. 24%, high- vs. low-grade gliomas, p = 0.004). There was no association of PINCH expression with gender, age, tumor number, size, histological type and tumor location (p > 0.05). CONCLUSIONS: PINCH expression may be involved in glioma development and differentiation.