The effects of different carbon sources(sugars) on the production and molecular properties of exopolysaccharides(EPS) were evaluated in the mycelial liquid culture of a medicinal fungus Cordyceps sinensis Cs-HK1. Gala...The effects of different carbon sources(sugars) on the production and molecular properties of exopolysaccharides(EPS) were evaluated in the mycelial liquid culture of a medicinal fungus Cordyceps sinensis Cs-HK1. Galactose or mannose was used(at 5 g·L^(-1)) as a secondary carbon source with glucose(35 g·L^(-1)) at the mass ratio of 1:7. Mannose was consumed notably since the first day of culture, but galactose was not even after glucose was exhausted.The volumetric yield of EPS in culture was increased slightly with the addition of galactose and decreased with mannose. The monosaccharide composition of EPS was also different, e.g., on day 8, the glucose contents of EPS were 76%with the addition of mannose, 59% with galactose, compared with 62% with glucose only. The molecular weight distribution of EPS was also affected by the secondary carbon source, being generally lower compared with that with glucose only. The results suggested that the addition of galactose improved the total yield of EPS in culture while mannose can improve the yield of glucan constituent of EPS.展开更多
Colletotrichum gloeosporioides is the causal agent of anthracnose disease in fruits and vegetables, representing a global problem. The use of biocontrol agents has proved effective against fungal diseases in a wide va...Colletotrichum gloeosporioides is the causal agent of anthracnose disease in fruits and vegetables, representing a global problem. The use of biocontrol agents has proved effective against fungal diseases in a wide variety of products. In this work, the antifungal activity of Wickerhamomyces anomalus against C. gloeosporioides isolated from contaminated avocados was evaluated. The antagonism and volatile compound inhibition were measured on Petri dishes. In the mixed cultures, the mycelia damage was observed by scanning electron microscope (SEM). Chitinase and glucanase production by the antagonism was quantified by the reducing sugars method, and biofilm formation was evaluated with 1% crystal violet. The yeast W. anomalus could reduce the growth of C. gloeosporioides up to 65% by direct antagonism and 10% by volatile compounds. The antagonist did not allow the conidia germination and mycelia growth in any of the tested formulations. SEM showed mycelial damage caused by W. anomalus. The antagonist showed adhesion to the mycelium by a polysaccharide biofilm. The presence of mycelium stimulated the hydrolytic enzyme production with the maximal activity of 21.4 U/mg for chitinases at 24 h and 10 U/mg for glucanases at 60 h. These results showed that W. anomalus used together different mechanisms to express its antifungal activity against C. gloeosporioides. This study might be the first report for this phytopathogen isolated from avocado fruits, which could represent an opportunity to establish biocontrol of diseases for this agricultural product.展开更多
Objective:To study the role of intracellular calcium signal pathway in the down-regulation of aggrecan induced by cyclic tensile strain in the annulus fibrosus cells. Methods:The expression of aggrecan mRNA and core p...Objective:To study the role of intracellular calcium signal pathway in the down-regulation of aggrecan induced by cyclic tensile strain in the annulus fibrosus cells. Methods:The expression of aggrecan mRNA and core protein were respectively detected with RT-PCR and western blot after the channels transmitting calcium ions were blocked with EGTA, gadolinium and verapamil. Results :EGTA. gadolinium and verapamil partially prevented the effects of cyclic tensile strain on the expression of aggrecan in annulus fibrosus cells. Conclusion:The calcium signaling is involved in the down-regulation of proteoglycan resulting from cyclic tensile strain in the annulus fibrosus cells.展开更多
OBJECTIVE: To evaluate the potential beneficial effects of Inonotus obliquuspolysaccharides(IOP) on the alleviation of physical fatigue in mice.METHODS: Sixty-four male mice were randomly divided into four groups(n = ...OBJECTIVE: To evaluate the potential beneficial effects of Inonotus obliquuspolysaccharides(IOP) on the alleviation of physical fatigue in mice.METHODS: Sixty-four male mice were randomly divided into four groups(n = 16 per group). Mice were orally administered IOP for a period of 14 days at 0,100,200 and 300 mg/kg/d,and were assigned to the control,IOP-100,IOP-200,and IOP-300 groups,respectively by the random number table method. Mice in the control group received an oral administration of sterile distilled water. A forced swimming test was performed for 8 mice per group at one hour after the last treatment. The other 8mice in each group swam for 30 min. Blood,liver and muscle samples were taken after resting for30 min. Levels of blood urea nitrogen and lactate,as well as glycogen contents of the liver and muscle were measured. Morphology of liver was observed by light microscopy.RESULTS: IOP extended the swimming time of mice,and increased the glycogen content of liver and muscle,but decreased blood lactic acid and serum urea nitrogen levels. IOP had no toxic effects on major organs such as the liver as assessed by histopathological examinations.CONCLUSION: IOP might be a potential anti-fatigue pharmacological agent.展开更多
基金Supported by The Hong Kong Polytechnic University internal grants(G-UC14 and G-YBB4)
文摘The effects of different carbon sources(sugars) on the production and molecular properties of exopolysaccharides(EPS) were evaluated in the mycelial liquid culture of a medicinal fungus Cordyceps sinensis Cs-HK1. Galactose or mannose was used(at 5 g·L^(-1)) as a secondary carbon source with glucose(35 g·L^(-1)) at the mass ratio of 1:7. Mannose was consumed notably since the first day of culture, but galactose was not even after glucose was exhausted.The volumetric yield of EPS in culture was increased slightly with the addition of galactose and decreased with mannose. The monosaccharide composition of EPS was also different, e.g., on day 8, the glucose contents of EPS were 76%with the addition of mannose, 59% with galactose, compared with 62% with glucose only. The molecular weight distribution of EPS was also affected by the secondary carbon source, being generally lower compared with that with glucose only. The results suggested that the addition of galactose improved the total yield of EPS in culture while mannose can improve the yield of glucan constituent of EPS.
文摘Colletotrichum gloeosporioides is the causal agent of anthracnose disease in fruits and vegetables, representing a global problem. The use of biocontrol agents has proved effective against fungal diseases in a wide variety of products. In this work, the antifungal activity of Wickerhamomyces anomalus against C. gloeosporioides isolated from contaminated avocados was evaluated. The antagonism and volatile compound inhibition were measured on Petri dishes. In the mixed cultures, the mycelia damage was observed by scanning electron microscope (SEM). Chitinase and glucanase production by the antagonism was quantified by the reducing sugars method, and biofilm formation was evaluated with 1% crystal violet. The yeast W. anomalus could reduce the growth of C. gloeosporioides up to 65% by direct antagonism and 10% by volatile compounds. The antagonist did not allow the conidia germination and mycelia growth in any of the tested formulations. SEM showed mycelial damage caused by W. anomalus. The antagonist showed adhesion to the mycelium by a polysaccharide biofilm. The presence of mycelium stimulated the hydrolytic enzyme production with the maximal activity of 21.4 U/mg for chitinases at 24 h and 10 U/mg for glucanases at 60 h. These results showed that W. anomalus used together different mechanisms to express its antifungal activity against C. gloeosporioides. This study might be the first report for this phytopathogen isolated from avocado fruits, which could represent an opportunity to establish biocontrol of diseases for this agricultural product.
文摘Objective:To study the role of intracellular calcium signal pathway in the down-regulation of aggrecan induced by cyclic tensile strain in the annulus fibrosus cells. Methods:The expression of aggrecan mRNA and core protein were respectively detected with RT-PCR and western blot after the channels transmitting calcium ions were blocked with EGTA, gadolinium and verapamil. Results :EGTA. gadolinium and verapamil partially prevented the effects of cyclic tensile strain on the expression of aggrecan in annulus fibrosus cells. Conclusion:The calcium signaling is involved in the down-regulation of proteoglycan resulting from cyclic tensile strain in the annulus fibrosus cells.
基金Supported by Science and Technology Research program of Jilin Province,Education Department in the 12th Five Year Plan(China)(Research on Prevention of Inonotus Obliquus Polysaccharides for High Power Microwave Radiation Induced Injury in Rats,No.2012495)
文摘OBJECTIVE: To evaluate the potential beneficial effects of Inonotus obliquuspolysaccharides(IOP) on the alleviation of physical fatigue in mice.METHODS: Sixty-four male mice were randomly divided into four groups(n = 16 per group). Mice were orally administered IOP for a period of 14 days at 0,100,200 and 300 mg/kg/d,and were assigned to the control,IOP-100,IOP-200,and IOP-300 groups,respectively by the random number table method. Mice in the control group received an oral administration of sterile distilled water. A forced swimming test was performed for 8 mice per group at one hour after the last treatment. The other 8mice in each group swam for 30 min. Blood,liver and muscle samples were taken after resting for30 min. Levels of blood urea nitrogen and lactate,as well as glycogen contents of the liver and muscle were measured. Morphology of liver was observed by light microscopy.RESULTS: IOP extended the swimming time of mice,and increased the glycogen content of liver and muscle,but decreased blood lactic acid and serum urea nitrogen levels. IOP had no toxic effects on major organs such as the liver as assessed by histopathological examinations.CONCLUSION: IOP might be a potential anti-fatigue pharmacological agent.