Fungus Aspergillus sp., which was isolated from soft coral Sarcophyton tortuosum, was cultured in the GPY medium containing glucose 10 g/L, peptone 5 g/L, yeast extract 2 g/L, sea water 1 L, at pH=7.5. Four com pounds...Fungus Aspergillus sp., which was isolated from soft coral Sarcophyton tortuosum, was cultured in the GPY medium containing glucose 10 g/L, peptone 5 g/L, yeast extract 2 g/L, sea water 1 L, at pH=7.5. Four com pounds, 3,6-diisobutyl-2（1H）-pyrazinone（1）, 3-isobutyl-6-（1-hydroxy-2-methylpropyl）-2（1H）-pyrazinone（2）, 3-methoxy-4-methyl-2,4-dien-pentanoic acid（3） and penicillic acid（4） were obtained from the AcOEt extract of the culture broth. Their structures were elucidated mainly based on the NMR, HR-EI-MS and X-ray single crystal diffraction experimental data. Compound 3 is a new compound. Compound 1 was previously proposed to be the tautomer of flavacol（3,6-diisobutylpyrazin-2-ol, 5）. However, the evaluation of the NMR and X-ray single crystal diffraction experimental data permitted us to propose that compound 1 existed as amide form instead oftautomers. Compound 1 is stable both in solution and crystal due to strong intermolecular hydrogen bonds. Incidentally supplying anthracenone to the GPY medium with a dose of 100 mg/L, the yield of penicillic acid（4） in the culture broth of the strain Aspergillus sp. was increased dramatically from 6 mg/L to 57 mg/L.展开更多
The cellulase cocktail produced by marine Aspergillus niger exhibits a property of salt-tolerance,which is of great potential in cellulose degradation in high salt environment.In order to explain the mechanism on the ...The cellulase cocktail produced by marine Aspergillus niger exhibits a property of salt-tolerance,which is of great potential in cellulose degradation in high salt environment.In order to explain the mechanism on the salttolerance of the cellulase cocktail produced by marine A.niger,six cellulase components(AnCel6,AnCel7A,AnCel7B,AnEGL,AnBGL1 and AnBGL2)were obtained by directed expression.Studies on their enzymatic properties revealed that oneβ-glucosidase(AnBGL2)and one endoglucanase(AnEGL)exhibited an outstanding salttolerant property,and one cellobiohydrolase(AnCel7B)exhibited a certain salt-tolerant property.Subsequent study revealed that the salt-tolerant An EGL and AnCel7B endowed the cellulase cocktail with stronger salttolerant property,while the salt-tolerant An BGL2 had no positive effect.Moreover,after overexpression of AnCel6,AnCel7A,AnCel7B and AnEGL,the activity of cellulase cocktail increased by 80%,70%,63%and 68%,respectively.However,the activity of cellulase cocktail was not improved after overexpression of AnBGL1 and AnBGL2.After mixed-strain fermentation with cellobiohydrolase recombinants(cel6 a,cel7a and cel7b recombinants)and endoglucanase recombinant(egl recombinant),the the activity of cellulase cocktail increased by 114%,102%and91%,respectively.展开更多
Thirty-six strains of marine actinomycetes were isolated from a sample of marine sediment collected from the Yellow Sea and evaluated in terms of their inhibitory activity on the growth of Aspergillus parasiticus and ...Thirty-six strains of marine actinomycetes were isolated from a sample of marine sediment collected from the Yellow Sea and evaluated in terms of their inhibitory activity on the growth of Aspergillus parasiticus and the production of norsolorinic acid using dual culture plate assay and agar diffusion methods.Among them,three strains showed strong antifungal activity and were subsequently identified as Streptomyces sp.by 16 S rRNA gene sequencing analysis.The supernatant from the fermentation of the MA01 strain was extracted sequentially with chloroform and ethyl acetate,and the activities of the extracts were determined by tip culture assay.The assay results show that both extracts inhibited mycelium growth and toxin production,and the inhibitory activities of the extracts increased as their concentrations increased.The results of this study suggest that marine actinomycetes are biologically important for the control of mycotoxins,and that these bacteria could be used as novel biopesticides against mycotoxins.展开更多
The effect of decumbenones A (1), B (2) and C (3) from the marine-derived strain of the fungus Aspergillus sulphureus on the growth of seedling roots of buckwheat, wheat, barley and corn at the concentration range 10...The effect of decumbenones A (1), B (2) and C (3) from the marine-derived strain of the fungus Aspergillus sulphureus on the growth of seedling roots of buckwheat, wheat, barley and corn at the concentration range 10﹣5 - 10﹣18 M was studied. It was shown that decumbenone B had a stimulatory effect on the growth of seedling roots of buckwheat, decumbenone A—on the growth of seedling roots of spring soft wheat, decumbenone C—on the growth of seedling roots of spring barley, decumbenone A, B and C —on the growth of seedling roots of corn. The stimulatory effect for some substances was shown at ultra-low concentrations 10﹣12 - 10﹣18 M. It is possible to recommend decumbenones A, B and C for studying in field conditions as growth factors of buckwheat, wheat, barley and corn.展开更多
[Objective] The research aimed to isolate the glyphosate-degraded strain and study its degradation characteristics.[Method] A glyphosate-degraded fungal strain A-F02 was isolated from sludge in an aeration tank of a g...[Objective] The research aimed to isolate the glyphosate-degraded strain and study its degradation characteristics.[Method] A glyphosate-degraded fungal strain A-F02 was isolated from sludge in an aeration tank of a glyphosate manufacture.The fungal strain A-F02 was identified according to morphological characteristics and internal transcribed spacer（ITS）region of nuclear ribosomal DNA sequence analysis.The glyphosate-biodegraded characteristics of strain A-F02 and the influencing factors were studied.[Result] The fungal strain A-F02 was identified as Aspergillus oryzae sp..The glyphosate-biodegraded rate was 86.82% in the mineral salt medium with 1 000 mg/L of glyphosate as the sole source of carbon,after being incubated at 30 ℃ and 150 rpm for 7 d.The biodegradation rates and biomass of the A-F02 were the highest under the culture conditions with glucose（0.5%,w/v）,pH 7.5,30 ℃ and glyphosate（1 500 mg/L）.[Conclusion] The research provided the experimental basis for glyphosate-biodegraded enzyme purification.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.20502036 and 20602044)the Natural Science Founda-tion of Guangdong Province(No.05300667) the Fund for Innovative Chemical Experiment and Research of School of Chemi-stry and Chemical Engineering, Sun Yat-sen University, China
文摘Fungus Aspergillus sp., which was isolated from soft coral Sarcophyton tortuosum, was cultured in the GPY medium containing glucose 10 g/L, peptone 5 g/L, yeast extract 2 g/L, sea water 1 L, at pH=7.5. Four com pounds, 3,6-diisobutyl-2（1H）-pyrazinone（1）, 3-isobutyl-6-（1-hydroxy-2-methylpropyl）-2（1H）-pyrazinone（2）, 3-methoxy-4-methyl-2,4-dien-pentanoic acid（3） and penicillic acid（4） were obtained from the AcOEt extract of the culture broth. Their structures were elucidated mainly based on the NMR, HR-EI-MS and X-ray single crystal diffraction experimental data. Compound 3 is a new compound. Compound 1 was previously proposed to be the tautomer of flavacol（3,6-diisobutylpyrazin-2-ol, 5）. However, the evaluation of the NMR and X-ray single crystal diffraction experimental data permitted us to propose that compound 1 existed as amide form instead oftautomers. Compound 1 is stable both in solution and crystal due to strong intermolecular hydrogen bonds. Incidentally supplying anthracenone to the GPY medium with a dose of 100 mg/L, the yield of penicillic acid（4） in the culture broth of the strain Aspergillus sp. was increased dramatically from 6 mg/L to 57 mg/L.
基金supported by National Natural Science Foundation of China(21576233,21878263)Fundamental Research Funds for the Central Universities。
文摘The cellulase cocktail produced by marine Aspergillus niger exhibits a property of salt-tolerance,which is of great potential in cellulose degradation in high salt environment.In order to explain the mechanism on the salttolerance of the cellulase cocktail produced by marine A.niger,six cellulase components(AnCel6,AnCel7A,AnCel7B,AnEGL,AnBGL1 and AnBGL2)were obtained by directed expression.Studies on their enzymatic properties revealed that oneβ-glucosidase(AnBGL2)and one endoglucanase(AnEGL)exhibited an outstanding salttolerant property,and one cellobiohydrolase(AnCel7B)exhibited a certain salt-tolerant property.Subsequent study revealed that the salt-tolerant An EGL and AnCel7B endowed the cellulase cocktail with stronger salttolerant property,while the salt-tolerant An BGL2 had no positive effect.Moreover,after overexpression of AnCel6,AnCel7A,AnCel7B and AnEGL,the activity of cellulase cocktail increased by 80%,70%,63%and 68%,respectively.However,the activity of cellulase cocktail was not improved after overexpression of AnBGL1 and AnBGL2.After mixed-strain fermentation with cellobiohydrolase recombinants(cel6 a,cel7a and cel7b recombinants)and endoglucanase recombinant(egl recombinant),the the activity of cellulase cocktail increased by 114%,102%and91%,respectively.
基金Supported by the China Ocean Mineral Resources Research and Development Association Project(No.DY125-15-R-01)the National Natural Science Foundation of China(Nos.30870003,31100090)
文摘Thirty-six strains of marine actinomycetes were isolated from a sample of marine sediment collected from the Yellow Sea and evaluated in terms of their inhibitory activity on the growth of Aspergillus parasiticus and the production of norsolorinic acid using dual culture plate assay and agar diffusion methods.Among them,three strains showed strong antifungal activity and were subsequently identified as Streptomyces sp.by 16 S rRNA gene sequencing analysis.The supernatant from the fermentation of the MA01 strain was extracted sequentially with chloroform and ethyl acetate,and the activities of the extracts were determined by tip culture assay.The assay results show that both extracts inhibited mycelium growth and toxin production,and the inhibitory activities of the extracts increased as their concentrations increased.The results of this study suggest that marine actinomycetes are biologically important for the control of mycotoxins,and that these bacteria could be used as novel biopesticides against mycotoxins.
文摘The effect of decumbenones A (1), B (2) and C (3) from the marine-derived strain of the fungus Aspergillus sulphureus on the growth of seedling roots of buckwheat, wheat, barley and corn at the concentration range 10﹣5 - 10﹣18 M was studied. It was shown that decumbenone B had a stimulatory effect on the growth of seedling roots of buckwheat, decumbenone A—on the growth of seedling roots of spring soft wheat, decumbenone C—on the growth of seedling roots of spring barley, decumbenone A, B and C —on the growth of seedling roots of corn. The stimulatory effect for some substances was shown at ultra-low concentrations 10﹣12 - 10﹣18 M. It is possible to recommend decumbenones A, B and C for studying in field conditions as growth factors of buckwheat, wheat, barley and corn.
文摘[Objective] The research aimed to isolate the glyphosate-degraded strain and study its degradation characteristics.[Method] A glyphosate-degraded fungal strain A-F02 was isolated from sludge in an aeration tank of a glyphosate manufacture.The fungal strain A-F02 was identified according to morphological characteristics and internal transcribed spacer（ITS）region of nuclear ribosomal DNA sequence analysis.The glyphosate-biodegraded characteristics of strain A-F02 and the influencing factors were studied.[Result] The fungal strain A-F02 was identified as Aspergillus oryzae sp..The glyphosate-biodegraded rate was 86.82% in the mineral salt medium with 1 000 mg/L of glyphosate as the sole source of carbon,after being incubated at 30 ℃ and 150 rpm for 7 d.The biodegradation rates and biomass of the A-F02 were the highest under the culture conditions with glucose（0.5%,w/v）,pH 7.5,30 ℃ and glyphosate（1 500 mg/L）.[Conclusion] The research provided the experimental basis for glyphosate-biodegraded enzyme purification.
