Aim: To compare the contents of nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia, and to study the effect of humidity and heat on the content of nucleosides. Methods: The contents of nucleos...Aim: To compare the contents of nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia, and to study the effect of humidity and heat on the content of nucleosides. Methods: The contents of nucleosides were determined by using high performance capillary electrophoresis (HPCE). Beckman P/ACE System 5010 apparatus equipped with a UV detector and a Beckman untreated fused-silica capillary (57 cm 75 mm, 50 cm effective length) was used. Before sample injection, the capillary was rinsed with 1 molL-1 sodium hydroxide solution and running buffer for 5 min, respectively. A voltage of 20 kV was applied for the separation. Pressure injection was 586 kPa for 6 seconds, and the wavelength of detector was 254 nm. The running time was 20 min at 20 oC. The effect of humidity and heat on the contents of nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia was observed for 1, 3, 5 and 10 days at temperature 40 oC, and relative humidity 75%. Results: The content of nucleosides from natural Cordyceps sinensis was higher than that from cultured Cordyceps mycelia. But the contents of nucleosides from freshly collected natural Cordyceps sinensis were very low, even below the limit of quantitation. The contents of nucleosides from natural Cordyceps sinensis were significantly increased by humidity and heat, but this phenomenon was not observed in cultured Cordyceps mycelia. Conclusion: There are differences between the nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia. The nucleosides in natural Cordyceps sinensis may be derived from the degradation of nucleic acids. This implies that adenosine being used for the quality control of natural Cordyceps sinensis may have to be reconsidered.展开更多
Aim A liquid chromatographic method for the determination ofcandicidin/FR-008 and related components in fermentation broth has been developed. Methods Therewere four major components in the candicidin/FR-008 complex, ...Aim A liquid chromatographic method for the determination ofcandicidin/FR-008 and related components in fermentation broth has been developed. Methods Therewere four major components in the candicidin/FR-008 complex, which were separated by HPLC under thefollowing conditions: SB-C8 column (4.6 mm x 250 mm, 5 μm) was used, the mobile phase consisted ofacetonitrileam-monium acteate (20 mmol·L^(-1) , pH 4.0) (40:60, V/V) , with a flow rate of 1 .0mL·min^(-1) , the UV detection wavelength was 380 nm, and the whole process was performed at 25℃ .Results The linearity was obtained in the range of 6.25 - 500 μg· mL^(-1) candicidin/FR-008 withthe regression equation of Y = 20 461 x + 30 748 and the correlation coefficient of 0.999 1. Theinstrument precision was 1.84% and the method precision was 3.8%. Conclusion This method isaccurate, rapid and simple; it can be used for determination of candicidin/FR-008 and relatedcomponents in fermentation broth.展开更多
[Objective] The aim was to isolate and identify a taxol-producing endophytic fungus from Taxus media. [Method] 32 strains of endophytic fungi were identified form the inner bark of T. media,and their fermentation prod...[Objective] The aim was to isolate and identify a taxol-producing endophytic fungus from Taxus media. [Method] 32 strains of endophytic fungi were identified form the inner bark of T. media,and their fermentation products were detected by high performance liquid chromatography (HPLC). [Result] Through the screening,a strain of taxol-producing endophytic fungi M57 was obtained,which could produce 45-50 μg/L of taxol,and M57 was defined as Rhizopus sp. through morphological observation and 18S rDNA sequence analysis. [Conclusion] The finding of Rhizopus sp. M57 provided a promising strain for producing taxol with taxol-producing fungi fermentation process.展开更多
Acid hydrolysis is a simple and direct way to hydrolyze polysaccharides in biomass into fermentable sugars. To produce fermentable sugars effectively and economically for fuel ethanol, we have investigated the hydroly...Acid hydrolysis is a simple and direct way to hydrolyze polysaccharides in biomass into fermentable sugars. To produce fermentable sugars effectively and economically for fuel ethanol, we have investigated the hydrolysis of Enteromorpha using acids that are typically used to hydrolyze biomass： H2SO4, HC1, H3PO4 and C4H404 （maleic acid）. 5%（w/w） Enteromorpha biomass was treated for different times （30, 60, and 90 min） and with different acid concentrations （0.6, 1.0, 1.4, 1.8, and 2.2%, w/w） at 121~C. H2SO4 was the most effective acid in this experiment. We then analyzed the hydrolysis process in H2SO4 in detail using high performance liquid chromatography. At a sulfuric acid concentration of 1.8% and treatment time of 60 min, the yield of ethanol fermentable sugars （glucose and xylose） was high, （230.5 mg/g dry biomass, comprising 175.2 mg/g glucose and 55.3 mg/g xylose）, with 48.6% of total reducing sugars being ethanol fermentable. Therefore, Enteromorpha could be a good candidate for production of fuel ethanol. In future work, the effects of temperature and biomass concentration on hydrolysis, and also the fermentation of the hydrolysates to ethanol fuel should be focused on.展开更多
Petrovska klobasa is a traditional dry fermented sausage produced in the Autonomous Province of Vojvodina. Formation of nine hiogenic amines was determined in three sausage groups produced from hot deboned （A1） and ...Petrovska klobasa is a traditional dry fermented sausage produced in the Autonomous Province of Vojvodina. Formation of nine hiogenic amines was determined in three sausage groups produced from hot deboned （A1） and cold meat （B1, B3） during drying and ripening in traditional room （A1, B1） and in industrial ripening chamber （B3）. Dansyl chloride derived amines were analysed by high-performance liquid chromatography with diode-array detector （HPLC-DAD） on Eclipse XDB-C18 column. Histamine, the most important amine from food safety point of view, was not found in any of the analyzed samples. Serotonin and spermidine were also not detected in any samples, while spermin was determined in all analyzed samples. At the end of drying, phenylethylamine was the predominant amine in A1 sausage group （51.6 mg/kg）, and tryptamine in B1 （38.1 mg/kg） and B3 （28.7 mg/kg） sausage groups. At the end of ripening, tryptamine was the predominant biogenic amine in all sausage groups （133, 121 and 39.8 mg/kg in A1, B1 and B3 groups, respectively）. Total level of biogenic amines in all investigated sausages did not exceed 174 mg/kg at the end of drying and 238 mg/kg at the end of ripening period. Tryptamine and cadaverine may be used as indicators of total biogenic amines for sausages produced in traditional and indusrial conditions from hot deboned and cold meat.展开更多
1,3-Propanediol （PDO） is an important bulk industrial material. It can be produced by microbial fermentation. In this study, the microbial flora of mangrove sediment was screened to identify strains with high produc...1,3-Propanediol （PDO） is an important bulk industrial material. It can be produced by microbial fermentation. In this study, the microbial flora of mangrove sediment was screened to identify strains with high production of PDO by fermentation of glycerol. The PDO productivities of the isolated strains were tested, and the strain with highest PDO productivity was characterized using the API20E and 16-s rRNA sequence analysis. The physiological and phylogenetic analysis indicated that the strain was closed related to K. pneumoniae species and was named as K. pneumoniae HSL4. The structure of the dha cluster which was responsible for the biosynthesis of PDO was analyzed. It is observed that K. pneumoniae HSL4 was tolerant to salt and partly tolerant to acetate and lactate, which will favor industrial applications. Fed-batch fermentation experiments revealed K. pneumoniae HSL4 exhibited an excellent ability to produce PDO with high concentration （80.08 g L^-1）, productivity （2.22 g L^-1h^-1） and conversion （0.435 g g^-1 or 0.53 mol mol^-1）. The metabolic flux profile illuminated that glycerol was consumed rapidly and PDO was accumulated quickly to a high level during the exponential growth phase. This study provided important information for further fermentation and metabolic engineering of PDO production by K. pneumoniae HSL4.展开更多
文摘Aim: To compare the contents of nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia, and to study the effect of humidity and heat on the content of nucleosides. Methods: The contents of nucleosides were determined by using high performance capillary electrophoresis (HPCE). Beckman P/ACE System 5010 apparatus equipped with a UV detector and a Beckman untreated fused-silica capillary (57 cm 75 mm, 50 cm effective length) was used. Before sample injection, the capillary was rinsed with 1 molL-1 sodium hydroxide solution and running buffer for 5 min, respectively. A voltage of 20 kV was applied for the separation. Pressure injection was 586 kPa for 6 seconds, and the wavelength of detector was 254 nm. The running time was 20 min at 20 oC. The effect of humidity and heat on the contents of nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia was observed for 1, 3, 5 and 10 days at temperature 40 oC, and relative humidity 75%. Results: The content of nucleosides from natural Cordyceps sinensis was higher than that from cultured Cordyceps mycelia. But the contents of nucleosides from freshly collected natural Cordyceps sinensis were very low, even below the limit of quantitation. The contents of nucleosides from natural Cordyceps sinensis were significantly increased by humidity and heat, but this phenomenon was not observed in cultured Cordyceps mycelia. Conclusion: There are differences between the nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia. The nucleosides in natural Cordyceps sinensis may be derived from the degradation of nucleic acids. This implies that adenosine being used for the quality control of natural Cordyceps sinensis may have to be reconsidered.
文摘Aim A liquid chromatographic method for the determination ofcandicidin/FR-008 and related components in fermentation broth has been developed. Methods Therewere four major components in the candicidin/FR-008 complex, which were separated by HPLC under thefollowing conditions: SB-C8 column (4.6 mm x 250 mm, 5 μm) was used, the mobile phase consisted ofacetonitrileam-monium acteate (20 mmol·L^(-1) , pH 4.0) (40:60, V/V) , with a flow rate of 1 .0mL·min^(-1) , the UV detection wavelength was 380 nm, and the whole process was performed at 25℃ .Results The linearity was obtained in the range of 6.25 - 500 μg· mL^(-1) candicidin/FR-008 withthe regression equation of Y = 20 461 x + 30 748 and the correlation coefficient of 0.999 1. Theinstrument precision was 1.84% and the method precision was 3.8%. Conclusion This method isaccurate, rapid and simple; it can be used for determination of candicidin/FR-008 and relatedcomponents in fermentation broth.
基金Supported by National Natural Science Foundation of China(20776058)New Century Training Programme Foundation for the Talents by the State Education Commission (NCET-06-0646)~~
文摘[Objective] The aim was to isolate and identify a taxol-producing endophytic fungus from Taxus media. [Method] 32 strains of endophytic fungi were identified form the inner bark of T. media,and their fermentation products were detected by high performance liquid chromatography (HPLC). [Result] Through the screening,a strain of taxol-producing endophytic fungi M57 was obtained,which could produce 45-50 μg/L of taxol,and M57 was defined as Rhizopus sp. through morphological observation and 18S rDNA sequence analysis. [Conclusion] The finding of Rhizopus sp. M57 provided a promising strain for producing taxol with taxol-producing fungi fermentation process.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2009AA10Z106)the Major State Basic Research Development Program(No.2011CB200902)+4 种基金the CAS International Innovation Partnership Program:Typical Environmental Process and Effects on Resources in Coastal Zone Areathe National Key Technology Research and Development Program(No.2008BAC49B01)the National Natural Science Foundation of China(Nos.40876082,30870247)Outstanding Young Scholar Fellowship of Shandong Province(No.JQ200914)the Science and Technology Project of Qingdao City(No.09-1-3-59-jch)
文摘Acid hydrolysis is a simple and direct way to hydrolyze polysaccharides in biomass into fermentable sugars. To produce fermentable sugars effectively and economically for fuel ethanol, we have investigated the hydrolysis of Enteromorpha using acids that are typically used to hydrolyze biomass： H2SO4, HC1, H3PO4 and C4H404 （maleic acid）. 5%（w/w） Enteromorpha biomass was treated for different times （30, 60, and 90 min） and with different acid concentrations （0.6, 1.0, 1.4, 1.8, and 2.2%, w/w） at 121~C. H2SO4 was the most effective acid in this experiment. We then analyzed the hydrolysis process in H2SO4 in detail using high performance liquid chromatography. At a sulfuric acid concentration of 1.8% and treatment time of 60 min, the yield of ethanol fermentable sugars （glucose and xylose） was high, （230.5 mg/g dry biomass, comprising 175.2 mg/g glucose and 55.3 mg/g xylose）, with 48.6% of total reducing sugars being ethanol fermentable. Therefore, Enteromorpha could be a good candidate for production of fuel ethanol. In future work, the effects of temperature and biomass concentration on hydrolysis, and also the fermentation of the hydrolysates to ethanol fuel should be focused on.
文摘Petrovska klobasa is a traditional dry fermented sausage produced in the Autonomous Province of Vojvodina. Formation of nine hiogenic amines was determined in three sausage groups produced from hot deboned （A1） and cold meat （B1, B3） during drying and ripening in traditional room （A1, B1） and in industrial ripening chamber （B3）. Dansyl chloride derived amines were analysed by high-performance liquid chromatography with diode-array detector （HPLC-DAD） on Eclipse XDB-C18 column. Histamine, the most important amine from food safety point of view, was not found in any of the analyzed samples. Serotonin and spermidine were also not detected in any samples, while spermin was determined in all analyzed samples. At the end of drying, phenylethylamine was the predominant amine in A1 sausage group （51.6 mg/kg）, and tryptamine in B1 （38.1 mg/kg） and B3 （28.7 mg/kg） sausage groups. At the end of ripening, tryptamine was the predominant biogenic amine in all sausage groups （133, 121 and 39.8 mg/kg in A1, B1 and B3 groups, respectively）. Total level of biogenic amines in all investigated sausages did not exceed 174 mg/kg at the end of drying and 238 mg/kg at the end of ripening period. Tryptamine and cadaverine may be used as indicators of total biogenic amines for sausages produced in traditional and indusrial conditions from hot deboned and cold meat.
基金supported by the Scientific Research Project of the Marine Public Welfare Industry of China (201205020-4)Administration of Ocean and Fisheries of Guangdong Province (GD2012-D01-002)
文摘1,3-Propanediol （PDO） is an important bulk industrial material. It can be produced by microbial fermentation. In this study, the microbial flora of mangrove sediment was screened to identify strains with high production of PDO by fermentation of glycerol. The PDO productivities of the isolated strains were tested, and the strain with highest PDO productivity was characterized using the API20E and 16-s rRNA sequence analysis. The physiological and phylogenetic analysis indicated that the strain was closed related to K. pneumoniae species and was named as K. pneumoniae HSL4. The structure of the dha cluster which was responsible for the biosynthesis of PDO was analyzed. It is observed that K. pneumoniae HSL4 was tolerant to salt and partly tolerant to acetate and lactate, which will favor industrial applications. Fed-batch fermentation experiments revealed K. pneumoniae HSL4 exhibited an excellent ability to produce PDO with high concentration （80.08 g L^-1）, productivity （2.22 g L^-1h^-1） and conversion （0.435 g g^-1 or 0.53 mol mol^-1）. The metabolic flux profile illuminated that glycerol was consumed rapidly and PDO was accumulated quickly to a high level during the exponential growth phase. This study provided important information for further fermentation and metabolic engineering of PDO production by K. pneumoniae HSL4.
