The separation and purification method for pepsin of Northern Sheatfish (Silurus soldatovi) was established by using the combination technology of salting-out,gel chromatography and gel electrophoresis,and the enzymic...The separation and purification method for pepsin of Northern Sheatfish (Silurus soldatovi) was established by using the combination technology of salting-out,gel chromatography and gel electrophoresis,and the enzymic properties were also analyzed.The experimental results indicated that 28% and 56% (NH4)2SO4 saturation could separate the activated protease from the pepsin extract of gastric mucosa of Sheatfish (Silurus soldatovi) ;compared with the homogenate extraction,the pepsin specific activity of purified extraction by Sephadex G-75 gel chromatography system increased 598 fold,was 5 times higher than that of activated liquid,and the total production rate was 10.1%.The purified pepsin liquor at the conditions of pH3.3 0.01 M alanine-formic acid buffering solution,60 cm chromatography column,and the flowing rate of 0.8 ML/min was analyzed by SDS-PAGE,which indicated that there were two bands and the molecular weight was 34.0 kDa and 40.4 kDa,respectively.There were two peaks in the enzyme activity determination of the separated collecting liquor in gel chromatography,and the SDS-PAGE showed the concentrations of the two proteins was different,which indicated that it existed at least two pepsins in the gastric mucosa of Sheatfish (Silurus soldatovi).展开更多
Xanthophyll has multiple physiological functions to improve the quality of farmed animals.The present study aimed to investigate the effects of xanthophyll on the growth performance,antioxidation,immunity,pigmentation...Xanthophyll has multiple physiological functions to improve the quality of farmed animals.The present study aimed to investigate the effects of xanthophyll on the growth performance,antioxidation,immunity,pigmentation and meat quality of southern catfish(Silurus soldatovi meridionalis Chen).Juvenile southern catfish(18.35±0.04 g)were randomly allocated into 24 cages(30 juveniles per cage),and fed diets with different dietary xanthophyll levels(at 14,42,80,108,126 and 152 mg/kg,dry matter of diet)twice daily for 8 weeks.Results indicated that the diet with 80 mg/kg xanthophyll induced a higher specific growth rate(SGR),feed efficiency ratio and protein productive value.Moreover,the 80 mg/kg xanthophyll diet also increased complement 3,immunoglobulin M(IgM)and lysozyme content more than the other groups.The mRNA expression level of inflammation-related genes and antioxidant enzyme activities further confirmed the effects of 80 mg/kg dietary xanthophyll on improving immune response.The present study also found that the 126 mg/kg xanthophyll diet significantly enhanced the content of total carotenoids and xanthophyll,hydroxyproline,collagen and amino acid in muscle.The diet with 126 mg/kg xanthophylls also induced lower drip loss,thawing loss,centrifugal loss,cooking loss and higher muscle adhesiveness,cohesiveness,springiness,gumminess and chewiness than the other treatments.In conclusion,quadratic regression model analysis based on SGR and IgM revealed that the optimum xanthophyll level in the diet was 86.78 and 84.63 mg/kg,respectively.Moreover,broken line regression analysis based on xanthophyll content in dorsal skin and chewiness in muscle demonstrated that the optimal xanthophyll level was between 89.73 and 108.66 mg/kg in the diet of southern catfish(S.soldatovi meridionalis Chen).展开更多
To provide a theoretical basis to improve the survival and growth rate and optimize diet of sheatfish （Silurus soldatovi）, the activities of certain digestive enzymes and alkaline phosphatases were investigated duri...To provide a theoretical basis to improve the survival and growth rate and optimize diet of sheatfish （Silurus soldatovi）, the activities of certain digestive enzymes and alkaline phosphatases were investigated during larval development of one-ten day old individuals. Results indicated that sheatfish larva （～ three days after hatching） had high levels of alkaline protease activity, which peaked at five days old and dipped by eight days old, although the trend was generally upward. Acid protease activity at one-eight days old was low, after which it increased rapidly. Amylase activity reached the highest value at five days old, after which it began to decline. Lipase activity fluctuated markedly and showed two peaks at three-four days old and six-eight days old. Larval digestive enzyme activity and alkaline phosphatase activity were higher when fed live food than when fed an artificial diet. Throughout the early development process, alkaline protease activity was higher than acid protease, alkaline protease and amylase specific activity decreased significantly for eight-day-old transition larvae, while acid protease activity increased rapidly. These results indicate that the changes in digestive enzyme activity were relevant to digestive function conversion during fish larvae development. Alkaline phosphatase activity showed an upward trend over the first ten days of life, which indicated that the gastrointestinal function of sheatfish improved gradually.展开更多
为探明发病怀头鲶Silurus soldatovi的病原及其生物学特征,从发病怀头鲶体内分离出1株革兰氏阴性细菌SG-1,通过细菌形态学观察、理化特性、16S r DNA测序和构建系统发育进化树分析对其进行了鉴定。结果表明:分离菌SG-1菌株葡萄糖产气、...为探明发病怀头鲶Silurus soldatovi的病原及其生物学特征,从发病怀头鲶体内分离出1株革兰氏阴性细菌SG-1,通过细菌形态学观察、理化特性、16S r DNA测序和构建系统发育进化树分析对其进行了鉴定。结果表明:分离菌SG-1菌株葡萄糖产气、氧化酶、硝酸盐还原为阳性,鸟氨酸脱羧酶、硫化氢为阴性;进一步采用PCR方法扩增其16S r DNA序列,测序获得片段大小为1409 bp,与维氏气单胞菌Aeromonas veronii模式菌株ATCC35624序列相似性达99.86%;构建系统发育树分析显示,分离菌与维氏气单胞菌自然聚为一支,最终判定SG-1菌株为维氏气单胞菌;人工感染斑马鱼Danio rerio、鲶S.soldatovi,其死亡率均达100%,病鱼呈现体表出血、肛门红肿、腹水等症状;药敏试验结果显示,该菌对头孢克肟、头孢哌酮、头孢噻肟、诺氟沙星、左氟沙星、恩诺沙星、氟苯尼考等药物敏感,对阿莫西林、氨苄西林、磺胺异恶唑、甲氧嘧啶、复方新诺明等耐药。本研究结果为了解维氏气单胞菌感染鲶的致病机理及其该病的预防治疗提供了科学参考。展开更多
The surface ultrastructure of mature egg chorion of the tamed northern sheatfish Silurus soldatovi in Heilongjiang river was investigated by scanning electron microscopy. The outermost layer was composed of a thin lam...The surface ultrastructure of mature egg chorion of the tamed northern sheatfish Silurus soldatovi in Heilongjiang river was investigated by scanning electron microscopy. The outermost layer was composed of a thin lamella of a jelly coat. The surface of jelly coat was characterized by overlapping net-like fibrillar lamellae, many clefts with bridges and pores. The pore canals were 0.25 μm in diameter. The pore density was about 0.7-1.0/μm-2. The pores on the surface of jelly coart were distributed uniformly. Mature eggs of sheatfish possessed a funnel-shaped micropyle in the animal polar region. The micropylar region was about 0.04 mm2 area in diameter with 3-8 ridges in radial arrangement. Fertilized eggs in which jelly coats were removed mechanically presented no adhesiveness and exhibited inlays of irregular granules on their surface.展开更多
基金Sponsored by the Key Research Program of Chinese Academy of Fishery Sciences (Grant No. 1999-01-10)Agricultural Science and Technology Fund of Department of Science and Technology (Grant No. 02EFN216900727)the National Natural Science Foundation of China (Grant No. 50638020)
文摘The separation and purification method for pepsin of Northern Sheatfish (Silurus soldatovi) was established by using the combination technology of salting-out,gel chromatography and gel electrophoresis,and the enzymic properties were also analyzed.The experimental results indicated that 28% and 56% (NH4)2SO4 saturation could separate the activated protease from the pepsin extract of gastric mucosa of Sheatfish (Silurus soldatovi) ;compared with the homogenate extraction,the pepsin specific activity of purified extraction by Sephadex G-75 gel chromatography system increased 598 fold,was 5 times higher than that of activated liquid,and the total production rate was 10.1%.The purified pepsin liquor at the conditions of pH3.3 0.01 M alanine-formic acid buffering solution,60 cm chromatography column,and the flowing rate of 0.8 ML/min was analyzed by SDS-PAGE,which indicated that there were two bands and the molecular weight was 34.0 kDa and 40.4 kDa,respectively.There were two peaks in the enzyme activity determination of the separated collecting liquor in gel chromatography,and the SDS-PAGE showed the concentrations of the two proteins was different,which indicated that it existed at least two pepsins in the gastric mucosa of Sheatfish (Silurus soldatovi).
基金supported by the Foundation and Applied Basic Research Fund Project of Guangdong Province(2019A1515110606)Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai).
文摘Xanthophyll has multiple physiological functions to improve the quality of farmed animals.The present study aimed to investigate the effects of xanthophyll on the growth performance,antioxidation,immunity,pigmentation and meat quality of southern catfish(Silurus soldatovi meridionalis Chen).Juvenile southern catfish(18.35±0.04 g)were randomly allocated into 24 cages(30 juveniles per cage),and fed diets with different dietary xanthophyll levels(at 14,42,80,108,126 and 152 mg/kg,dry matter of diet)twice daily for 8 weeks.Results indicated that the diet with 80 mg/kg xanthophyll induced a higher specific growth rate(SGR),feed efficiency ratio and protein productive value.Moreover,the 80 mg/kg xanthophyll diet also increased complement 3,immunoglobulin M(IgM)and lysozyme content more than the other groups.The mRNA expression level of inflammation-related genes and antioxidant enzyme activities further confirmed the effects of 80 mg/kg dietary xanthophyll on improving immune response.The present study also found that the 126 mg/kg xanthophyll diet significantly enhanced the content of total carotenoids and xanthophyll,hydroxyproline,collagen and amino acid in muscle.The diet with 126 mg/kg xanthophylls also induced lower drip loss,thawing loss,centrifugal loss,cooking loss and higher muscle adhesiveness,cohesiveness,springiness,gumminess and chewiness than the other treatments.In conclusion,quadratic regression model analysis based on SGR and IgM revealed that the optimum xanthophyll level in the diet was 86.78 and 84.63 mg/kg,respectively.Moreover,broken line regression analysis based on xanthophyll content in dorsal skin and chewiness in muscle demonstrated that the optimal xanthophyll level was between 89.73 and 108.66 mg/kg in the diet of southern catfish(S.soldatovi meridionalis Chen).
基金Agricultural Science and Technology Fund of Department of Science and Technology (02EFN216900727)
文摘To provide a theoretical basis to improve the survival and growth rate and optimize diet of sheatfish （Silurus soldatovi）, the activities of certain digestive enzymes and alkaline phosphatases were investigated during larval development of one-ten day old individuals. Results indicated that sheatfish larva （～ three days after hatching） had high levels of alkaline protease activity, which peaked at five days old and dipped by eight days old, although the trend was generally upward. Acid protease activity at one-eight days old was low, after which it increased rapidly. Amylase activity reached the highest value at five days old, after which it began to decline. Lipase activity fluctuated markedly and showed two peaks at three-four days old and six-eight days old. Larval digestive enzyme activity and alkaline phosphatase activity were higher when fed live food than when fed an artificial diet. Throughout the early development process, alkaline protease activity was higher than acid protease, alkaline protease and amylase specific activity decreased significantly for eight-day-old transition larvae, while acid protease activity increased rapidly. These results indicate that the changes in digestive enzyme activity were relevant to digestive function conversion during fish larvae development. Alkaline phosphatase activity showed an upward trend over the first ten days of life, which indicated that the gastrointestinal function of sheatfish improved gradually.
文摘为探明发病怀头鲶Silurus soldatovi的病原及其生物学特征,从发病怀头鲶体内分离出1株革兰氏阴性细菌SG-1,通过细菌形态学观察、理化特性、16S r DNA测序和构建系统发育进化树分析对其进行了鉴定。结果表明:分离菌SG-1菌株葡萄糖产气、氧化酶、硝酸盐还原为阳性,鸟氨酸脱羧酶、硫化氢为阴性;进一步采用PCR方法扩增其16S r DNA序列,测序获得片段大小为1409 bp,与维氏气单胞菌Aeromonas veronii模式菌株ATCC35624序列相似性达99.86%;构建系统发育树分析显示,分离菌与维氏气单胞菌自然聚为一支,最终判定SG-1菌株为维氏气单胞菌;人工感染斑马鱼Danio rerio、鲶S.soldatovi,其死亡率均达100%,病鱼呈现体表出血、肛门红肿、腹水等症状;药敏试验结果显示,该菌对头孢克肟、头孢哌酮、头孢噻肟、诺氟沙星、左氟沙星、恩诺沙星、氟苯尼考等药物敏感,对阿莫西林、氨苄西林、磺胺异恶唑、甲氧嘧啶、复方新诺明等耐药。本研究结果为了解维氏气单胞菌感染鲶的致病机理及其该病的预防治疗提供了科学参考。
文摘The surface ultrastructure of mature egg chorion of the tamed northern sheatfish Silurus soldatovi in Heilongjiang river was investigated by scanning electron microscopy. The outermost layer was composed of a thin lamella of a jelly coat. The surface of jelly coat was characterized by overlapping net-like fibrillar lamellae, many clefts with bridges and pores. The pore canals were 0.25 μm in diameter. The pore density was about 0.7-1.0/μm-2. The pores on the surface of jelly coart were distributed uniformly. Mature eggs of sheatfish possessed a funnel-shaped micropyle in the animal polar region. The micropylar region was about 0.04 mm2 area in diameter with 3-8 ridges in radial arrangement. Fertilized eggs in which jelly coats were removed mechanically presented no adhesiveness and exhibited inlays of irregular granules on their surface.
