•A novel polysaccharide (TPS) was extracted from the fermentation mycelia of Trichoderma kanganensis.•TPS was linked by α- and β-configuration, mainly Man, and its Mw was 3.074 × 105 Da.•TPS could ...inhibit the proliferation of the mouse colon cell lines (CT26).•TPS possessed the free radical scavenging activity on hydrogen peroxide.
A novel water-soluble polysaccharide designated as TPS was isolated from the fermentation mycelia of Trichoderma kanganensis. TPS had a weight-average molecular mass of 3.074 × 105 Da, and the monosaccharide composition was consisted of Man (45.5%), GlcA (5.5%), Glc (10%), and Gal (39%). The major backbone of TPS was →6-α-d-Galp-1→5-β-d-Manf-1→5,6-β-d-Manf-1→5,6-β-d-Manf-1→, and the side chains are α-d-Glcp-1→4-α-d-Glcp-1→, β-d-Galf-1→, and α-d-Glcp-1→. In addition, we demonstrated that TPS was non-toxic in normal cells (LO2 cells) and inhibited the proliferation of mouse colon cells (CT26 cells). TPS also showed free radical scavenging activity against hydrogen peroxide. Overall, these results suggested that TPS from Trichoderma kanganensis may have potential application in biomedical fields.
Aims
To study the effects of mixed culture fermentation (MCF) of Bacillus amyloliquefaciens and Trichoderma longibrachiatum on its constituent strains and the application values for agricultural ...production, with the intention of developing efficient and environmentally friendly biocontrol agents.
Methods and results
In this study, an in vitro antifungal growth experiment showed that the inhibitory rate of the MCF broth on pathogenic fungi (Fusarium oxysporum f. sp. lycopersici, Botrytis cinerea, Trichothecium roseum and Colletotrichum gloeosporioides) was less than that of B. amyloliquefaciens culture fermentation (BCF). Moreover, the content and gene expression of lipopeptide antibiotics were also lower than that in the BCF group. However, the pot experiments based on irrigation with appropriately diluted fermentation broth showed that the biocontrol effect of MCF on tomato Fusarium wilt was significantly higher than that of TCF (T. longibrachiatum culture fermentation) and BCF, and was approximately 15.79% higher than that of the BTF group which made by mixing equivalent amounts of BCF and TCF. In MCF broth, two micro‐organisms antagonized and coexisted, and the growth of T. longibrachiatum was inhibited. Using transcriptomic analysis, we speculated that MCF can upregulate the expression of genes related to carbon and nitrogen metabolism, oxidation–reduction activity, sporulation, environmental information response and chemotaxis, and biosynthesis of secondary metabolites of B. amyloliquefaciens, which might enhance the nutrient substances metabolism and competitiveness, survival ability, colonization and adaptability to the environment to increase its biocontrol potential.
Conclusions
Mixed culture fermentation could promote the more reasonable and effective utilization of biocontrol micro‐organisms though improving biocontrol effect, enhancing strains survival and competitiveness, increasing beneficial metabolites, combined with resistance induction or synergistic control.
Significance and Impact of the Study
Using MCF agronomically utilizes biocontrol agents in an efficient way, which has a good potential for commercial implementation and could reduce production costs.
A polysaccharide (BP) produced by Bacillus subtilis using burdock oligofructose as carbon source was isolated. The BP polysaccharide, which differed from starch and burdock oligofructose, was made up ...of a backbone structure of (1→6)-linked α-d-glucopyranosyl residues substituted at the O-3 position with α-d-glucopyranosyl branches. In vitro, BP exhibited an inhibitory effect on the proliferation of A549 cells and increased the production of reactive oxygen species promoting the apoptosis of cell. Moreover, it could up-regulate the expression of Caspase-3 gene and protein, indicating that BP activated the Caspase-3 pathway. These findings would be beneficial for the development of BP as dietary supplements and drug treated to cancer.
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•A polysaccharide (BP) produced by Bacillus subtilis using burdock oligofructose as carbon source was stimulated to generate.•The BP polysaccharide, was structurally composed of mannose, rhamnose, glucose, galactose and arabinose and its Mw was 1.533 × 107 g/mol.•The backbone structure of BP consisted of (1→6)-linked α-D-glucopyranosyl residues substituted at the O-3 position with α-D-glucopyranosyl branches.•The BP polysaccharide increased reactive oxygen species, up-regulated the expression level of caspase-3 in the gene and protein in A549 cells.
In this study, a polysaccharide, BP, was produced by Bacillus subtilis using burdock oligofructose as a carbon source. The polysaccharide BP was isolated from burdock fermented through B. subtilis by hot water extraction, ethanol precipitation, anion exchange and gel filtration chromatography. The molecular weight of BP was determined to be 1.533 × 107 g/mol, and is composed of mannose, rhamnose, glucose, galactose, and arabinose in the ratio of 1:0.12:17.16:0.69:1.10. Furthermore, BP is made up of a backbone structure of (1→6)-linked α-d-glucopyranosyl residues substituted at the O-3 position with α-d-glucopyranosyl branches. In vitro, BP inhibited A549 cell proliferation and increased reactive oxygen species production, thus, promoting the apoptosis of cells. Moreover, BP up-regulated the expression of caspase-3 and the corresponding protein, indicating that it activates the caspase-3 pathway. These findings suggest that the potential of BP as a supplement or drug to treat cancer.
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•The rhizosphere soil was treated with mixed culture fermentation broth (MCF).•Irrigation with MCF prolonged the shelf life of kiwi fruits.•Irrigation with MCF improved the size and ...quality of kiwi fruits.•Analysis of metabolites in kiwi fruit by metabolomics.
The effects of pre-harvest treatment of the rhizosphere soil of kiwifruit trees with mixed culture fermentation broth (MCF) of Trichoderma pseudokoningii and Rhizopus nigricans on post-harvest shelf life and fruit quality were investigated. The soil was irrigated with MCF in April, June, September, and November every year for two consecutive years. This agronomic measure significantly improved the productive parameters and quality traits of kiwi fruit and increased the total phenol and flavonoid content and superoxide dismutase (SOD) and peroxidase (POD) activities to different degrees on days 0, 10, and 15 during storage at 25 ℃. Further, the protein bands at different storage periods increased or decreased with the gradient of fermentation broth. Metabolomics analysis of LC-MS/MS data revealed that treatment with MCF altered several metabolites, including phytohormone, amino acids, vitamins, and flavonoids. These findings highlight the importance of further investigating the utility of pre-harvest MCF treatment in prolonging the shelf life and improving the quality of fruit, which may promote more reasonable and effective utilization of biocontrol agents in the future.
Fusarium wilt, caused by Fusarium oxysporum, is a devastating soilborne fungal disease. Compared to traditional chemical pesticides, biological control has been attracting increasing attention ...recently, owing to its eco-friendly features. This study investigated the potential use of mixed culture fermentation of Rhizopus nigricans and Trichoderma pseudokoningii (MCF) to control Fusarium oxysporum f.sp.cucumerinum (FOC). At first, the tablet confrontation experiment using bio-control fungi and F. oxysporum showed that the suppression rate of R. nigricans and T. pseudokoningii were more than 60% higher than that of individual fermentations. Furthermore, the inhibitory effect of MCF on the pathogen was higher than that of single fermentation broth, both in vitro and in greenhouse experiment. At the molecular level, MCF had better control on the number of pathogens in the plant tissue and soil, as seen by the real-time PCR assay. In the pot experiment, increased activities of the defense enzymes involved in PAL, SOD, and POD indicated that mixed broth treatment could increase the plant-induced resistance. In the field experiment, after two-year treatment by the mixed broth, the relative control effect on cucumber Fusarium wilt was 76.5%. Through this study, we demonstrated that co-fermentation of R. nigricans and T. pseudokoningii has synergistic effect on the control of F. oxysporum, which may promote more reasonable and effective utilization of biocontrol agents in future.
•We used mixed culture fermentation (MCF) for biological control of Fusarium wilt.•MCF of Rhizopus nigricans and Trichoderma pseudokoningii was used.•The relative control effect on cucumber Fusarium wilt was 76.5%.•Co-fermentation of R. nigricans and T. pseudokoningii showed a synergistic effect.
Abstract
Aims
Obesity is a risk factor of abdominal aortic aneurysm (AAA). Inflammatory cytokine interleukin-18 (IL18) has two receptors: IL18 receptor (IL18r) and Na-Cl co-transporter (NCC). In ...human and mouse AAA lesions, IL18 colocalizes to its receptors at regions rich in adipocytes, suggesting a role of adipocytes in promoting IL18 actions in AAA development.
Methods and results
We localized both IL18r and NCC in human and mouse AAA lesions. Murine AAA development required both receptors. In mouse AAA lesions, IL18 binding to these receptors increased at regions enriched in adipocytes or adjacent to perivascular adipose tissue. 3T3-L1 adipocytes enhanced IL18 binding to macrophages, aortic smooth muscle cells (SMCs), and endothelial cells by inducing the expression of both IL18 receptors on these cells. Adipocytes also enhanced IL18r and IL18 expression from T cells and macrophages, AAA-pertinent protease expression from macrophages, and SMC apoptosis. Perivascular implantation of adipose tissue from either diet-induced obese mice or lean mice but not that from leptin-deficient ob/ob mice exacerbated AAA development in recipient mice. Further experiments established an essential role of adipocyte leptin and fatty acid-binding protein 4 (FABP4) in promoting IL18 binding to macrophages and possibly other inflammatory and vascular cells by inducing their expression of IL18, IL18r, and NCC.
Conclusion
Interleukin-18 uses both IL18r and NCC to promote AAA formation. Lesion adipocyte and perivascular adipose tissue contribute to AAA pathogenesis by releasing leptin and FABP4 that induce IL18, IL18r, and NCC expression and promote IL18 actions.
Cronobacter species are opportunistic foodborne pathogens involved in neonatal infections from powdered infant formula (PIF). In this study, a novel saltatory rolling circle amplification (SRCA) ...method has been developed for detecting Cronobacter spp. in PIF. 16 of Cronobacter spp. strains and 32 of non-Cronobacter strains were examined by using the DNA-directed RNA polymerase subunit beta (rpoB) gene. All Cronobacter strains were identified in pure cultures, whereas no SRCA products were found in non-Cronobacter strains. The detection limits were 3.4 × 102 CFU/mL through observing the white precipitate by naked eye, while 3.4 × 101 CFU/mL by fluorescence visualization. After enrichment, the detection limits of SRCA method in PIF were 8.7 × 100 CFU/g and 8.7 × 10−1 CFU/g by visualization with white precipitate and fluorescence, respectively. Compared with the conventional PCR method, the SRCA has at least 100-fold higher sensitivity and 100-fold lower detection limit. In addition, 85 of PIF samples were investigated for the Cronobacter contamination, and the results were 100% sensitivity, 97.62% specificity and 97.65% accuracy compared with the ISO method. Therefore, the results show that SRCA is a sensitive and visual detection method for the detection of Cronobacter spp. in PIF with great potential.
•A sensitive and visual SRCA method was developed for the detection of Cronobacter in the powdered infant formula.•The SRCA assay was successfully amplified by using a pair of primers in an isothermal condition.•The detection results of SRCA assay were observed by white precipitate or fluorescence with naked eye.•The SRCA method was validated with artificially contaminated powdered infant formula.
Blood eosinophil count and ECP (eosinophil cationic protein) associate with human cardiovascular diseases. Yet, whether eosinophils play a role in cardiovascular disease remains untested. The current ...study detected eosinophil accumulation in human and murine abdominal aortic aneurysm (AAA) lesions, suggesting eosinophil participation in this aortic disease.
To test whether and how eosinophils affect AAA growth.
Population-based randomized clinically controlled screening trials revealed higher blood eosinophil count in 579 male patients with AAA than in 5063 non-AAA control (0.236±0.182 versus 0.211±0.154, 10
/L,
<0.001). Univariate (odds ratio, 1.381,
<0.001) and multivariate (odds ratio, 1.237,
=0.031) logistic regression analyses indicated that increased blood eosinophil count in patients with AAA served as an independent risk factor of human AAA. Immunostaining and immunoblot analyses detected eosinophil accumulation and eosinophil cationic protein expression in human and murine AAA lesions. Results showed that eosinophil deficiency exacerbated AAA growth with increased lesion inflammatory cell contents, matrix-degrading protease activity, angiogenesis, cell proliferation and apoptosis, and smooth muscle cell loss using angiotensin-II perfusion-induced AAA in
and eosinophil-deficient
ΔdblGATA mice. Eosinophil deficiency increased lesion chemokine expression, muted lesion expression of IL (interleukin) 4 and eosinophil-associated-ribonuclease-1 (mEar1 mouse EOS-associated-ribonuclease-1, human ECP homolog), and slanted M1 macrophage polarization. In cultured macrophages and monocytes, eosinophil-derived IL4 and mEar1 polarized M2 macrophages, suppressed CD11b
Ly6C
monocytes, and increased CD11b
Ly6C
monocytes. mEar1 treatment or adoptive transfer of eosinophil from wild-type and
mice, but not eosinophil from
mice, blocked AAA growth in
ΔdblGATA mice. Immunofluorescent staining and immunoblot analyses demonstrated a role for eosinophil IL4 and mEar1 in blocking NF-κB (nuclear factor-κB) activation in macrophages, smooth muscle cells, and endothelial cells.
Eosinophils play a protective role in AAA by releasing IL4 and cationic proteins such as mEar1 to regulate macrophage and monocyte polarization and to block NF-κB activation in aortic inflammatory and vascular cells.
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