Amorphophallus konjac is rich in glucomannan,which can be hydrolyzed into glucose and mannose,thereby acting as an economic raw material for the acquisition of glucose and mannose.The total sugar yield was 91.2%when k...Amorphophallus konjac is rich in glucomannan,which can be hydrolyzed into glucose and mannose,thereby acting as an economic raw material for the acquisition of glucose and mannose.The total sugar yield was 91.2%when konjac powder was treated with 0.75%hydrochloric acid at 121℃for 1 h.Thus,dilute acid hydrolysates of konjac powder were used as a carbon source for obtaining value-added products.Here we showed that the microbial production of ethanol and mannonic acid was obtained by employing Candida shehatae(C.shehatae)and Gluconobacter oxydans(G.oxydans).Through a step-by-step bioprocess,glucose is the first selectively converted to ethanol by C.shehatae,which enables G.oxydans-mediated biocatalysis of mannose to mannonic acid.Finally,approximately 100 g ethanol and 340 g mannonic acid were produced starting from 1 kg refined konjac powder.The results demonstrated the feasibility of this bioconversion method for producing mannonic acid starting from crude hydrolysates of konjac powder.展开更多
Drought can limit the growth and reduce the yield of crops,but the safe and effective bio-approach to improve the drought resistance of crops is very little.We conducted an experiment in which we monitored the effects...Drought can limit the growth and reduce the yield of crops,but the safe and effective bio-approach to improve the drought resistance of crops is very little.We conducted an experiment in which we monitored the effects of polysaccharide from the endophyte Bionectria sp.Fat6 on the growth of Tartary buckwheat(Fagopyrum tataricum(L.)Gaertn)seedlings under control and drought-stressed conditions by determining gas exchange,photosynthesis parameters,photosynthetic pigment contents,and metabolite accumulation.Results indicated that the polysaccharide from endophyte stimulated plant growth and increased the aboveground biomass,root mass,and root/shoot ratio of Tartary buckwheat.Application of the polysaccharide to drought-stressed plants resulted in a significant increase in the net photosynthetic rate,stomatal conductance,and transpiration rate of Tartary buckwheat and decreased the intercellular CO_(2) concentration.The contents of chlorophyll a,chlorophyll b,chlorophyll a+b,and carotenoids in leaves were higher in polysaccharide-treated seedlings than that in control.Polysaccharide notably increased the soluble protein and proline content and decreased the malondialdehyde content in Tartary buckwheat leaves.The endophytic polysaccharide may protect Tartary buckwheat against drought by improving leaf gas exchange and photosynthetic capacity,and altering concentrations of protective metabolites.Together,these changes may compensate for the negative impacts of drought stress on the growth of Tartary buckwheat.Thus,the polysaccharide from the endophyte Bionectria sp.Fat6 may be an effective biotic elicitor and a promising bio-approach to improve Tartary buckwheat production worldwide.展开更多
A new thiacalix[4]arene phenothiazine derivative(2) based on a thiacalix[4]crown with a 1,3-alternate conformation has been synthesized and characterized. In THF-water mixture, Compound 2 exhibits a strong fluorescenc...A new thiacalix[4]arene phenothiazine derivative(2) based on a thiacalix[4]crown with a 1,3-alternate conformation has been synthesized and characterized. In THF-water mixture, Compound 2 exhibits a strong fluorescence emission, with a large Stokes shift(λex/em = 357 nm/505 nm, Δλ = 148 nm), which helps to avoid interference in excitation and emission. For the metal ions tested, the fluorescence of Compound 2 was quenched only by Fe3+ and Cr3+ ions. Evidence for the hydrolysis reaction promoted by the metal ions is given by X-ray crystallography, mass spectra(MS), infrared(IR) spectra, and fluorescence spectroscopy data.展开更多
基金the financial support from the National Natural Science Foundation of China(31901270)the Scientific Research Start-up Funds of Nanjing Forestry University,China(163030127).
文摘Amorphophallus konjac is rich in glucomannan,which can be hydrolyzed into glucose and mannose,thereby acting as an economic raw material for the acquisition of glucose and mannose.The total sugar yield was 91.2%when konjac powder was treated with 0.75%hydrochloric acid at 121℃for 1 h.Thus,dilute acid hydrolysates of konjac powder were used as a carbon source for obtaining value-added products.Here we showed that the microbial production of ethanol and mannonic acid was obtained by employing Candida shehatae(C.shehatae)and Gluconobacter oxydans(G.oxydans).Through a step-by-step bioprocess,glucose is the first selectively converted to ethanol by C.shehatae,which enables G.oxydans-mediated biocatalysis of mannose to mannonic acid.Finally,approximately 100 g ethanol and 340 g mannonic acid were produced starting from 1 kg refined konjac powder.The results demonstrated the feasibility of this bioconversion method for producing mannonic acid starting from crude hydrolysates of konjac powder.
基金This work was funded by National Key R&D Program of China(Grant No.2019YFD1001302/2019YFD1001300)Supported by National Natural Science Foundation of China(31771716+2 种基金3160126031701358)the earmarked fund for China Agriculture Research System(CARS-07-02A).
文摘Drought can limit the growth and reduce the yield of crops,but the safe and effective bio-approach to improve the drought resistance of crops is very little.We conducted an experiment in which we monitored the effects of polysaccharide from the endophyte Bionectria sp.Fat6 on the growth of Tartary buckwheat(Fagopyrum tataricum(L.)Gaertn)seedlings under control and drought-stressed conditions by determining gas exchange,photosynthesis parameters,photosynthetic pigment contents,and metabolite accumulation.Results indicated that the polysaccharide from endophyte stimulated plant growth and increased the aboveground biomass,root mass,and root/shoot ratio of Tartary buckwheat.Application of the polysaccharide to drought-stressed plants resulted in a significant increase in the net photosynthetic rate,stomatal conductance,and transpiration rate of Tartary buckwheat and decreased the intercellular CO_(2) concentration.The contents of chlorophyll a,chlorophyll b,chlorophyll a+b,and carotenoids in leaves were higher in polysaccharide-treated seedlings than that in control.Polysaccharide notably increased the soluble protein and proline content and decreased the malondialdehyde content in Tartary buckwheat leaves.The endophytic polysaccharide may protect Tartary buckwheat against drought by improving leaf gas exchange and photosynthetic capacity,and altering concentrations of protective metabolites.Together,these changes may compensate for the negative impacts of drought stress on the growth of Tartary buckwheat.Thus,the polysaccharide from the endophyte Bionectria sp.Fat6 may be an effective biotic elicitor and a promising bio-approach to improve Tartary buckwheat production worldwide.
基金supported by the National Key Research and Development Program(2021YFA0716400)the General Program of Natural Science Foundation of China(62274134)+3 种基金the National Science Fund for Distinguished Young Scholars(61925404)Wuhu and Xidian University Special Fund for Industry-university-research Cooperation(XWYCXY-012021005)the National Key Science and Technology Special Project(2009ZYHW0015)the Fundamental Research Funds for the Central Universities(JBF201101)。
基金supported by the National Natural Science Foundation of China(21165006)the Fund of the International Cooperation Projects of Guizhou Province(20137002)the"Chun-Hui"Fund of Chinese Ministry of Education(Z2011033 and Z2012053)
文摘A new thiacalix[4]arene phenothiazine derivative(2) based on a thiacalix[4]crown with a 1,3-alternate conformation has been synthesized and characterized. In THF-water mixture, Compound 2 exhibits a strong fluorescence emission, with a large Stokes shift(λex/em = 357 nm/505 nm, Δλ = 148 nm), which helps to avoid interference in excitation and emission. For the metal ions tested, the fluorescence of Compound 2 was quenched only by Fe3+ and Cr3+ ions. Evidence for the hydrolysis reaction promoted by the metal ions is given by X-ray crystallography, mass spectra(MS), infrared(IR) spectra, and fluorescence spectroscopy data.
