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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.
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•EPS1-1 inhibited metastasis by suppressing migration and invasion activities of CT26 cells.•EPS1-1 suppressed tube formation of HUVECs and angiogenesis in lung metastatic ...tissue.•EPS1-1 inhibited the activities and expressions of MMP-2 and MMP-9 in vitro and in vivo.
Polysaccharide (EPS1-1) extracted from fermentation liquor of Rhizopus nigricans possesses antitumor and immune-enhancing activities. The study was the first to investigate the anti-metastasis effects of EPS1-1 in vitro and in vivo. Results suggested that EPS1-1 dose-dependently suppressed the migration, invasion and adhesion abilities of CT26 cells. Furthermore, EPS1-1 dramatically inhibited the enzyme activity and expression levels of matrix metalloproteinases (MMPs) in CT26 cells, as well as the tube formation of HUVECs. Similar results were observed in the lung metastasis mice which were administrated with EPS1-1 for 14 d. EPS1-1 could inhibit angiogenesis by decreasing the expression of vascular endothelial growth factor (VEGF) and microvessel density (MVD) in lung tissue. Moreover, vimentin, as a marker molecule in epithelial-mesenchymal transition (EMT) which is closely related to metastasis, was found to be down expression by EPS1-1 in CT26 cells and lung tissue. These results suggested that EPS1-1 could suppress metastasis in vitro and in vivo by inhibiting invasion and angiogenesis, which provides potential application to against colorectal cancer metastasis.
The postharvest pathogens such as R. nigricans, A. flavas and P. expansum are the causal agents of jujube or orange fruit, therefore, in vitro and in vivo antifungal activities of cinnamon oil to ...inactivate these fungi were investigated. Cinnamaldehyde is the main constituent of cinnamon oil. The minimum inhibitory concentrations of cinnamon oil against Rhizopus nigricans, Aspergillus flavus and Penicillium expansum were 0.64% (v/v), 0.16% (v/v) and 0.16% (v/v), respectively. The antifungal activity of cinnamon oil against A. flavus and P. expansum was stronger than that against R. nigricans and the activity was improved with increasing its concentration. In an in vivo study, cinnamon oil with concentrations of 2.0% (v/v) and 3.0% (v/v) showed complete control the growth of fungi in wound-inoculated Lingwu Long Jujube and Sand Sugar Orange fruits. These results revealed that cinnamon oil has a good potential to be as a natural antifungal agent for fruit applications.
Rhizopus nigricans (R. nigricans)
, one of the fungi that grows the fastest, is frequently discovered in postharvest fruits, it’s the main pathogen of strawberry root rot. Flavonoids in
Sedum aizoon
...L. (FSAL) is a kind of green and safe natural substance extracted from
Sedum aizoon
L. which has antifungal activity. In this study, the minimum inhibitory concentration (MIC) of FSAL on
R. nigricans
and cell apoptosis tests were studied to explore the inhibitory effect of FSAL on
R. nigricans
. The effects of FSAL on mitochondria of
R. nigricans
were investigated through the changes of mitochondrial permeability transition pore(mPTP), mitochondrial membrane potential(MMP), Ca
2+
content, H
2
O
2
content, cytochrome
c
(
Cyt c
) content, the related enzyme activity and related genes of mitochondria. The results showed that the MIC of FSAL on
R. nigricans
was 1.800 mg/mL, with the addition of FSAL (1.800 mg/mL), the mPTP openness of
R. nigricans
increased and the MMP reduced. Resulting in an increase in Ca
2+
content, accumulation of H
2
O
2
content and decrease of
Cyt c
content, the activity of related enzymes was inhibited and related genes were up-regulated (
VDAC1, ANT
) or down-regulated (
SDHA, NOX2
). This suggests that FSAL may achieve the inhibitory effect of fungi by damaging mitochondria, thereby realizing the postharvest freshness preservation of strawberries. This lays the foundation for the development of a new plant-derived antimicrobial agent.
The present study aims to analyze the structural characterization and antioxidant activity of a novel exopolysaccharide from
(EPS2-1). For this purpose, EPS2-1 was purified through DEAE-52, Sephadex ...G-100, and Sephadex G-75 chromatography. The structural characterization of EPS2-1 was analyzed using high-performance gel permeation chromatography (HPGPC), Fourier transform infrared spectroscopy (FT-IR), methylation analysis, nuclear magnetic resonance (NMR) spectra, transmission electron microscope (TEM), and atomic force microscope (AFM). The results revealed that EPS2-1 is composed of mannose (Man), galactose (Gal), glucose (Glc), arabinose (Ara), and Fucose (Fuc), and possesses a molecular weight of 32.803 kDa. The backbone of EPS2-1 comprised →2)-α-D-Man
-(1→ and →3)-β-D-Gal
-(1→, linked with the O-6 position of (→2,6)-α-D-Man
-(1→) of the main chain is branch α-D-Man
-(1→6)-α-D-Man
-(1→, linked with the O-6 positions of (→3)-β-D-Gal
-(1→) of the main chain are branches →4)-β-D-Glcp-(1→ and →3)-β-D-Galp-(1→, respectively. Finally, we demonstrated that EPS2-1 also shows free radical scavenging activity and iron ion reducing ability. At the same time, EPS2-1 could inhibit the proliferation of MFC cells and increase the cell viability of RAW264.7 cells. Our results suggested that EPS2-1 is a novel polysaccharide, and EPS2-1 has antioxidant activity. In addition, EPS2-1 may possess potential immunomodulatory and antitumor activities. This study promoted the application of EPS2-1 as the functional ingredients in the pharmaceutical and food industries.
•A homogeneous polysaccharide (RPS-1) was extracted from Rhizopus nigricans.•RPS-1 was non-starch α-1,6 branched α-1,4-glucan and its Mw was 1.617 × 107 g/mol.•MAPKs and NF-κB pathways were involved ...in macrophages activation induced by RPS-1.•Intragastric administration of RPS-1 inhibited tumor growth of CT26 tumor-bearing mice.
In this study, a homogeneous polysaccharide (RPS-1) was extracted from liquid-cultured mycelia of Rhizopus nigricans. The weight-average molecular weight of RPS-1 was 1.617 × 107 g/mol and structural characterization indicated that RPS-1 was a non-starch glucan which consisted of a backbone structure of (1→4)-linked α-d-glucopyranosyl residues substituted at the O-6 position with α-d-glucopyranosyl branches. RPS-1 stimulated the production of nitric oxide and tumor necrosis factor-α by triggering phosphorylation of mitogen-activated protein kinases and nuclear translocation of nuclear factor kappa B p65 in RAW 264.7 macrophage cells. Moreover, intragastric administration of RPS-1 improved the immune function of CT26 tumor-bearing mice and significantly inhibited the growth of transplanted tumor. In combination with 5-FU, RPS-1 enhanced antitumor activity of 5-FU and alleviated its toxicity on immune system. These findings suggested that RPS-1 has the potential for the development of functional foods and dietary supplements.
We aimed to develop a consortium of starter culture of effective microorganisms to prepare doenjang, a traditional Korean fermented food. Different ratios of Bacillus subtilis TKSP 24 (B), ...Aspergillus oryzae complex (A), Rhizopus nigricans (also named as Rhizopus stolonifera) (R), and Mucor racemosus 15 (M15) were selected as meju starter cultures to produce doenjang with improved quality. Microbial strain combinations (B: A: R and B: M15: R) were mixed separately at three different ratios 1:1:1 (w/w), 1:0.5:1.5 (w/w), and 1:1.5:0.5 (w/w) to prepare BAR-1, BAR-2, BAR-3, BM15R-1, BM15R-2, and BM15R-3 doenjang samples. Quantitative analyses included free amino acids, free sugar, volatile and non-volatile organic acids, cellular antioxidant activity along with the presence of biogenic amines and aflatoxins, and microbial counts. Total free amino acids responsible for the sweet taste of doenjang were highest in BAR-2 (322.50 mg/100 g) and BM15R-3 (320.07 mg/100 g). Total volatile organic acid was highest in BAR-1 compared to other preparations. All doenjang samples had biogenic amines, especially histamine, below the toxicity level (500 mg/kg). Also, the aflatoxin and hazardous microbial count in the tested doenjang samples were below the level of toxicity. The findings suggest that use of multiple microbial strains in combination with R. nigricans as a starter culture could be a novel and effective approach to improve the nutrition and safety of fermented soybean food products of doenjang.
•Polysaccharides (RPS) were extracted from fermented mycelia of Rhizopus nigricans.•RPS induced apoptotic cell death through mitochondrial pathway in BGC-823 cells.•RPS induced G2/M phase cell cycle ...arrest in BGC-823 cells.
In this study, we reported that polysaccharides (RPS) from the mycelia of liquid-cultured Rhizopus nigricans inhibited the proliferation and clonogenic potential of human gastric cancer BGC-823 cells. Results of acridine orange/ethidium bromide and Hoechst 33258 staining showed that treated cells displayed typical morphological characteristics of apoptosis such as condensation of chromatin, nuclear pyknosis and formation of apoptotic bodies. Flow cytometry analyses and colorimetric assay indicated that RPS induced mitochondria-mediated apoptosis which was associated with collapse of mitochondrial membrane potential, activation of caspase-9 and caspase-3, generation of intracellular reactive oxygen species and elevation of intracellular calcium in BGC-823 cells. Moreover, cell-cycle analysis revealed that RPS arrested cells in the G2/M phase of the cell cycle. These results provided further insights into the potential use of RPS as an anti-cancer agent against human gastric cancer.
This study was aimed to investigate the anti-tumor and immunomodulatory activities of an exopolysaccharide (EPS) from Rhizopus nigricans. Our results showed EPS could significantly inhibit the tumor ...growth and increase the immune organs index of CT26 tumor-bearing mice. EPS treatment increased the productions of interleukin-2 (IL-2) and tumor necrosis factor-α (TNF-α) levels in serum. The increase of percentage of CD8+ cytotoxic T cells among total spleen T lymphocyte was also observed. Furthermore, EPS remarkably stimulate spleen lymphocytes proliferation in the absence or presence of mitogens. In addition, we found that EPS had synergistic effect with chemotherapy and improved immunosuppressive effect induced by 5-Fu. In summary, these findings indicated that the antitumor effects of EPS might be partly due to immune function activation and it might have potential to be used in the treatment for colorectal cancer.
•EPS effectively inhibit the tumor growth of CT26 tumor-bearing mice.•EPS possessed an anti-tumor effect may be achieved by enhancing the immune system function.•EPS possessed a synergistic effect with chemotherapy and improved immunocompetence of CT26 tumor-bearing mice damaged by 5-Fu.
•A homogeneous exopolysaccharide (EPS1-1) was purified from the fermentation broth of Rhizopus nigricans.•EPS1-1 inhibited the proliferation of HCT-166 cells by triggering S phase cell cycle arrest ...and apoptosis.•Mitochondrial apoptotic pathway was involved in the apoptotic cell death induced by EPS1-1.
In this study, a homogeneous exopolysaccharide (EPS1-1) was purified from the fermentation broth of Rhizopus nigricans. EPS1-1 was composed of glucose, mannose, galactose and fructose in the molar ratio of 5.89:3.64:3.20:1.00 with weight average molecular weight of 9.7×103g/mol. EPS1-1 could significantly inhibit proliferation of human colorectal carcinoma HCT-116 cells in vitro. EPS1-1 also induced S phase cell cycle arrest and increased sub-G0/G1 population, a hallmark of apoptosis. The results of morphological characterization and flow cytometry showed that EPS1-1 induced apoptotic cell death in HCT-116 cells. EPS1-1 caused dissipation of mitochondrial membrane potential, accumulation of reactive oxygen species, up-regulation of Bax and p53 mRNA expression and down-regulation of Bcl-2 mRNA expression, which suggested that mitochondrial pathway was involved in the EPS1-1-induced apoptosis. These findings bring new insights into the potential use of EPS1-1 as antitumor drug against human colorectal carcinoma.
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