采用扫描电子显微镜(scanning electron microscopy,SEM)观察暗纹东方鲀鱼皮内外2层皮肤微观结构,基于实验室前期优化的提取和脱苦工艺,用复合蛋白酶提取暗纹东方鲀鱼皮胶原蛋白肽,活性炭和硅藻土对其酶解液进行吸附脱苦,最后以感官、...采用扫描电子显微镜(scanning electron microscopy,SEM)观察暗纹东方鲀鱼皮内外2层皮肤微观结构,基于实验室前期优化的提取和脱苦工艺,用复合蛋白酶提取暗纹东方鲀鱼皮胶原蛋白肽,活性炭和硅藻土对其酶解液进行吸附脱苦,最后以感官、电子舌、氨基酸组成和气相色谱-质谱(gas chromatography-mass spectrometry,GC-MS)分析评价脱苦效果。结果表明,暗纹东方鲀鱼皮外层皮肤的刺排列规则,内层皮肤则有褶皱,不平整;胶原蛋白肽酶解液经活性炭和硅藻土脱苦后苦味感官评分为3.3,低于脱苦前评分4.8(P<0.05);经电子舌分析脱苦后苦味响应值为5.2,低于脱苦前响应值6.8(P<0.05);脱苦后疏水性氨基酸含量为29.75%,低于脱苦前含量33.63%(P<0.05);脱苦后呈苦味的物质对乙酰氨基酚相对含量为4.36%,低于脱苦前相对含量26.58%(P<0.05)。该研究用活性炭和硅藻土对暗纹东方鲀鱼皮胶原蛋白肽酶解液苦味物质进行吸附后取得了一定的脱苦效果,为多肽苦味物质的脱除提供一定的理论支撑。展开更多
To investigate the changes of the biochemical composition of American shad(Alosa sapidissima) eggs and larvae at embryonic and early larval stages, samples were collected at different development stages from artificia...To investigate the changes of the biochemical composition of American shad(Alosa sapidissima) eggs and larvae at embryonic and early larval stages, samples were collected at different development stages from artificial fertilization to the end of yolk absorption including 2 h, 12 h and 30 h after fertilization and newly hatched larvae including 1 and 3 days after hatching. The composition of lipid, fatty acids, protein and amino acids were analyzed. The content of total protein exhibited a decreasing trend during embryogenesis and larval development, and a significant reduction was detected after hatching(P < 0.05). The total lipid content remained relative stable. A significant reduction was detected in almost all amino acids after hatching except for glycine(P <0.05), while a significant decrease was found in the content of cysteine, proline, tyrosine, valine, isoleucine, leucine and phenylalanine during the yolk-sac phase(P < 0.05). On the other hand, all the groups of fatty acids remained stable during the period of embryogenesis. But after hatching, a significant decrease was found in the content of C18:2n-6, C18:3n-6, SFA and ratio of EPA/ARA(P < 0.05), while a significant increase was found in the content of C18:3n-3, C20:4n-6, C22:6n-3 and ratio of n-3/n-6(P < 0.05). In conclusion, the combined data suggested that American shad utilizes the protein content as preferential energy substrates during embryonic and early larval developments with some specificity in the consumption of different amino acids.展开更多
We describe organogenesis at a histological level in American shad( Alosa sapidissima) larvae from 0 until 45 days after hatching(DAH). Larval development was divided into four stages based on the feeding mode,externa...We describe organogenesis at a histological level in American shad( Alosa sapidissima) larvae from 0 until 45 days after hatching(DAH). Larval development was divided into four stages based on the feeding mode,external morphological features,and structural changes in the organs: stage 1(0–2 DAH),stage 2(3–5 DAH),stage 3(6–26 DAH) and stage 4(27–45 DAH). At early stage 2(3 DAH),American shad larvae developed the initial digestive and absorptive tissues,including the mouth and anal opening,buccopharyngeal cavity,oesophagus,incipient stomach,anterior and posterior intestine,differentiated hepatocytes,and exocrine pancreas. The digestive and absorptive capacity developed further in stages 2 to 3,at which time the pharyngeal teeth,taste buds,gut mucosa folds,differentiated stomach,and gastric glands could be observed. Four defined compartments were discernible in the heart at 4 DAH. From 3 to 13 DAH,the excretory systems started to develop,accompanied by urinary bladder opening,the appearance and development of primordial pronephros,and the proliferation and convolution of renal tubules. Primordial gills were detected at 2 DAH,the pseudobranch was visible at 6 DAH,and the filaments and lamellae proliferated rapidly during stage 3. The primordial swim bladder was first observed at 2 DAH and started to inflate at 9 DAH; from then on,it expanded constantly. The spleen was first observed at 8 DAH and the thymus was evident at 12 DAH. From stage 4 onwards,most organs essentially manifested an increase in size,number,and complexity of tissue structure.展开更多
The catfishes are a group of economically important freshwater fish in China,which in recent years have suffered heavy losses as a result of bacterial outbreaks.In this study,we examined the diversity of the microbiom...The catfishes are a group of economically important freshwater fish in China,which in recent years have suffered heavy losses as a result of bacterial outbreaks.In this study,we examined the diversity of the microbiome of infected skin mucus of yellow catfish(Pelteobagrus fulvidraco)and channel catfish(Ictalurus punctatus)and analyzed the bacterial pathogens.We found several common pathogenic bacteria,such as Aeromonas spp.,Vibrio spp.,Moraxella spp.and Proteus spp.present in both fish species,but with significantly different bacterial community structures.We isolated and cultured Aeromonas veronii and Proteus mirabilis and validated their infectivity in zebrafish(Danio rerio)and yellow catfish.Intraperitoneal injection of either bacteria into zebrafish,but not immersion,caused 100%mortality and ovary fragmentation.Yellow catfish was more sensitive than zebrafish with 100%mortality in the immersion challenges with A.veronii or P.mirabilis,and with a higher abundance of A.veronii in the P.mirabilis-challenged group compared to control.To our knowledge,this is the first study on the pathogenicity of P.mirabilis in yellow catfish,and the results will help to develop effective strategies for the disease prevention and control in catfish farming.展开更多
文摘采用扫描电子显微镜(scanning electron microscopy,SEM)观察暗纹东方鲀鱼皮内外2层皮肤微观结构,基于实验室前期优化的提取和脱苦工艺,用复合蛋白酶提取暗纹东方鲀鱼皮胶原蛋白肽,活性炭和硅藻土对其酶解液进行吸附脱苦,最后以感官、电子舌、氨基酸组成和气相色谱-质谱(gas chromatography-mass spectrometry,GC-MS)分析评价脱苦效果。结果表明,暗纹东方鲀鱼皮外层皮肤的刺排列规则,内层皮肤则有褶皱,不平整;胶原蛋白肽酶解液经活性炭和硅藻土脱苦后苦味感官评分为3.3,低于脱苦前评分4.8(P<0.05);经电子舌分析脱苦后苦味响应值为5.2,低于脱苦前响应值6.8(P<0.05);脱苦后疏水性氨基酸含量为29.75%,低于脱苦前含量33.63%(P<0.05);脱苦后呈苦味的物质对乙酰氨基酚相对含量为4.36%,低于脱苦前相对含量26.58%(P<0.05)。该研究用活性炭和硅藻土对暗纹东方鲀鱼皮胶原蛋白肽酶解液苦味物质进行吸附后取得了一定的脱苦效果,为多肽苦味物质的脱除提供一定的理论支撑。
基金supported by the Jiangsu Province Technology Infrastructure Construction Project(No.BM201312)the Qingdao postdoctoral application research project(No.Q51201611)the State Level Commonweal Project of Research Institutes(No.20603022015005)
文摘To investigate the changes of the biochemical composition of American shad(Alosa sapidissima) eggs and larvae at embryonic and early larval stages, samples were collected at different development stages from artificial fertilization to the end of yolk absorption including 2 h, 12 h and 30 h after fertilization and newly hatched larvae including 1 and 3 days after hatching. The composition of lipid, fatty acids, protein and amino acids were analyzed. The content of total protein exhibited a decreasing trend during embryogenesis and larval development, and a significant reduction was detected after hatching(P < 0.05). The total lipid content remained relative stable. A significant reduction was detected in almost all amino acids after hatching except for glycine(P <0.05), while a significant decrease was found in the content of cysteine, proline, tyrosine, valine, isoleucine, leucine and phenylalanine during the yolk-sac phase(P < 0.05). On the other hand, all the groups of fatty acids remained stable during the period of embryogenesis. But after hatching, a significant decrease was found in the content of C18:2n-6, C18:3n-6, SFA and ratio of EPA/ARA(P < 0.05), while a significant increase was found in the content of C18:3n-3, C20:4n-6, C22:6n-3 and ratio of n-3/n-6(P < 0.05). In conclusion, the combined data suggested that American shad utilizes the protein content as preferential energy substrates during embryonic and early larval developments with some specificity in the consumption of different amino acids.
基金Supported by the National Spark Program of China(No.2012GA690001)
文摘We describe organogenesis at a histological level in American shad( Alosa sapidissima) larvae from 0 until 45 days after hatching(DAH). Larval development was divided into four stages based on the feeding mode,external morphological features,and structural changes in the organs: stage 1(0–2 DAH),stage 2(3–5 DAH),stage 3(6–26 DAH) and stage 4(27–45 DAH). At early stage 2(3 DAH),American shad larvae developed the initial digestive and absorptive tissues,including the mouth and anal opening,buccopharyngeal cavity,oesophagus,incipient stomach,anterior and posterior intestine,differentiated hepatocytes,and exocrine pancreas. The digestive and absorptive capacity developed further in stages 2 to 3,at which time the pharyngeal teeth,taste buds,gut mucosa folds,differentiated stomach,and gastric glands could be observed. Four defined compartments were discernible in the heart at 4 DAH. From 3 to 13 DAH,the excretory systems started to develop,accompanied by urinary bladder opening,the appearance and development of primordial pronephros,and the proliferation and convolution of renal tubules. Primordial gills were detected at 2 DAH,the pseudobranch was visible at 6 DAH,and the filaments and lamellae proliferated rapidly during stage 3. The primordial swim bladder was first observed at 2 DAH and started to inflate at 9 DAH; from then on,it expanded constantly. The spleen was first observed at 8 DAH and the thymus was evident at 12 DAH. From stage 4 onwards,most organs essentially manifested an increase in size,number,and complexity of tissue structure.
基金supported by National Key Research and Development Program of China[2018YFD0900601]The Belt and Road international joint laboratory construction projects of science and technology innovation action plan from Science and Technology Commission of Shanghai Municipality[19590750500]to L.Chen.
文摘The catfishes are a group of economically important freshwater fish in China,which in recent years have suffered heavy losses as a result of bacterial outbreaks.In this study,we examined the diversity of the microbiome of infected skin mucus of yellow catfish(Pelteobagrus fulvidraco)and channel catfish(Ictalurus punctatus)and analyzed the bacterial pathogens.We found several common pathogenic bacteria,such as Aeromonas spp.,Vibrio spp.,Moraxella spp.and Proteus spp.present in both fish species,but with significantly different bacterial community structures.We isolated and cultured Aeromonas veronii and Proteus mirabilis and validated their infectivity in zebrafish(Danio rerio)and yellow catfish.Intraperitoneal injection of either bacteria into zebrafish,but not immersion,caused 100%mortality and ovary fragmentation.Yellow catfish was more sensitive than zebrafish with 100%mortality in the immersion challenges with A.veronii or P.mirabilis,and with a higher abundance of A.veronii in the P.mirabilis-challenged group compared to control.To our knowledge,this is the first study on the pathogenicity of P.mirabilis in yellow catfish,and the results will help to develop effective strategies for the disease prevention and control in catfish farming.
