Many metabolites produced by various microorganisms have proven their usefulness in the area concerning human health. However, most of their diverse natural compound biosyntheses are hardly discovered. These metabolit...Many metabolites produced by various microorganisms have proven their usefulness in the area concerning human health. However, most of their diverse natural compound biosyntheses are hardly discovered. These metabolites might have specific or novel functions and these diverse active compounds can be achieved by biosynthesis, semi-biosynthesis, or chemical synthesis. A strategy to exploit the biosynthesis potential of a fungal strain is to use various culture conditions and to evaluate the chemical profiles of the culture extracts. The value of this approach was demonstrated with the fungal strain Aigialus parvus BCC 5311, producer of hypothemycin, aigialospirol, and aigialomycin A-D. The optimization of hypothemycin production and its derivative diversity by Aigialus parvus BCC 5311 was carried out using qualitative (general factorial design) and quantitative analysis (two-level fractional factorial design). Qualitative analysis revealed that soluble starch and yeast extract were shown to be the best carbon and nitrogen source respectively for the production of hypothemycin, aigialospirol and aigialomycin A-D. Quantitative analysis showed that the initial pH of culture medium is the most important factor that affects the production of hypothemycin and its derivatives (aigialospirol and aigialomycin A-D) production. Optimal medium composition used in a 5 L bioreactor generated a specific growth rate of A. parvus BCC 5311 of 0.0295 h-1, biomass yield of 1.6 g×gstarch-1, hypothemycin yield of 13.6 mg×gbiomass-1, and hypothemycin production rate of 0.6 mg×L-1×day-1. The maximum concentration of 58.0 mg×L-1 of hypothemycin was obtained at 120 h of culturing. Furthermore, the Aigialomycin A-D and Aigialospirol obtained were diversified towards various cultural conditions used. The high amount of hypothemycin produced and the diversity of derivatives obtained from this study should be useful for future mass production.展开更多
Objective: To confirm whether Bungarus multicinctus crude venom induces the apoptosis of K562 tumor cells and to find out the components inducing apoptosis of K562 cells from the crude venom. Methods: the crude venom ...Objective: To confirm whether Bungarus multicinctus crude venom induces the apoptosis of K562 tumor cells and to find out the components inducing apoptosis of K562 cells from the crude venom. Methods: the crude venom separated and purified by cation exchange chromatography, and the effect of venoms on K562 was studied by MTT method and flow cytometry. Results: The crude venom began to kill K562 cells at than 8103ng/ml (the survival rate was 82.5%) concentration and the effect was more significant in 24 h when administrating 8105ng/ml (the survival rate was 29.4%) crude venom. Apoptotic bodies were observed in the K562 tumor cells by fluorescent microscopy after administration of 5 mg/ml cycloheximide (CHX) or the peak VI solution at about 8105 ng/ml. The same results were detected by the flow cytometry. A sub-G1 peak appeared after administration of CHX or the sixth peak solution. Conclusion: The authors found that the venom can kill K562 tumor cells in time- and dose-dependent manner. However, the killing effect of the venom is not apoptosis. What抯 more, the peak VI solution, a component of the crude venom can induce the apoptosis of K562 tumor cells.展开更多
文摘Many metabolites produced by various microorganisms have proven their usefulness in the area concerning human health. However, most of their diverse natural compound biosyntheses are hardly discovered. These metabolites might have specific or novel functions and these diverse active compounds can be achieved by biosynthesis, semi-biosynthesis, or chemical synthesis. A strategy to exploit the biosynthesis potential of a fungal strain is to use various culture conditions and to evaluate the chemical profiles of the culture extracts. The value of this approach was demonstrated with the fungal strain Aigialus parvus BCC 5311, producer of hypothemycin, aigialospirol, and aigialomycin A-D. The optimization of hypothemycin production and its derivative diversity by Aigialus parvus BCC 5311 was carried out using qualitative (general factorial design) and quantitative analysis (two-level fractional factorial design). Qualitative analysis revealed that soluble starch and yeast extract were shown to be the best carbon and nitrogen source respectively for the production of hypothemycin, aigialospirol and aigialomycin A-D. Quantitative analysis showed that the initial pH of culture medium is the most important factor that affects the production of hypothemycin and its derivatives (aigialospirol and aigialomycin A-D) production. Optimal medium composition used in a 5 L bioreactor generated a specific growth rate of A. parvus BCC 5311 of 0.0295 h-1, biomass yield of 1.6 g×gstarch-1, hypothemycin yield of 13.6 mg×gbiomass-1, and hypothemycin production rate of 0.6 mg×L-1×day-1. The maximum concentration of 58.0 mg×L-1 of hypothemycin was obtained at 120 h of culturing. Furthermore, the Aigialomycin A-D and Aigialospirol obtained were diversified towards various cultural conditions used. The high amount of hypothemycin produced and the diversity of derivatives obtained from this study should be useful for future mass production.
基金This work was supported by the National Natural Science Foundation of China(No. 39570238)
文摘Objective: To confirm whether Bungarus multicinctus crude venom induces the apoptosis of K562 tumor cells and to find out the components inducing apoptosis of K562 cells from the crude venom. Methods: the crude venom separated and purified by cation exchange chromatography, and the effect of venoms on K562 was studied by MTT method and flow cytometry. Results: The crude venom began to kill K562 cells at than 8103ng/ml (the survival rate was 82.5%) concentration and the effect was more significant in 24 h when administrating 8105ng/ml (the survival rate was 29.4%) crude venom. Apoptotic bodies were observed in the K562 tumor cells by fluorescent microscopy after administration of 5 mg/ml cycloheximide (CHX) or the peak VI solution at about 8105 ng/ml. The same results were detected by the flow cytometry. A sub-G1 peak appeared after administration of CHX or the sixth peak solution. Conclusion: The authors found that the venom can kill K562 tumor cells in time- and dose-dependent manner. However, the killing effect of the venom is not apoptosis. What抯 more, the peak VI solution, a component of the crude venom can induce the apoptosis of K562 tumor cells.
