[Objective] This study aimed to screen a bacterial strain capable of producing bioflocculant. [Method] A bacterial strain T-11 capable of producing bioflocculant was isolated from activated sludge. Detailed tests on t...[Objective] This study aimed to screen a bacterial strain capable of producing bioflocculant. [Method] A bacterial strain T-11 capable of producing bioflocculant was isolated from activated sludge. Detailed tests on the morphological, physiological and biochemical characteristics were carried out and identification was performed to identify the strain. Finally, the bioflocculant was isolated and purified, and the flocculating activity and chemical characteristics were measured. [Result] It was identified as Serratia plumuthica based on its morphological, physiological and biochemical characteristics. This strain secreted flocculant best in a culture medium which included sucrose and NaNO3. The maximal cell growth was achieved within 10 h and the flocculating activity paralleled to it. It was found to be effective for flocculation of kaolin suspension, when added at a final concentration of 0.7 mg/L, over a range of pHs （2-7）, and temperature （approximately 30-80 ℃）. Chemical analysis indicated that the bioflocculant was an acidic polysaccharide consisting of glucose, glucuronic acid and galactose, talose and altrose. Infrared spectrum analysis also revealed typical characteristics of polysaccharides. [Conclusion] The biofloccu- lants produced by strain T-11 can greatly improve the ability of activated sludge to settle.展开更多
A 12-week feeding trial was conducted to evaluate the effects of dietary stachyose on the growth performance, digestive enzymes activities and intestinal structures of juvenile turbot(Scophthalmus maximus L). Five iso...A 12-week feeding trial was conducted to evaluate the effects of dietary stachyose on the growth performance, digestive enzymes activities and intestinal structures of juvenile turbot(Scophthalmus maximus L). Five isonitrogenous(49.58% crude protein) and isolipidic(10.50% crude lipid) diets were formulated to contain 0(Control), 0.625%(S-0.625), 1.25%(S-1.25), 2.5%(S-2.5) and 5%(S-5) stachyose, respectively. With the increase of stachyose level, the growth performance and feed utilization of turbot, such as the specific growth rate, final mean body weight, weight gain rate and feed efficiency, increased significantly(P < 0.05) and then stabilized. The feed intake of fish fed S-5 was significantly higher(P < 0.05) than that of fish in other groups. The activities of trypsin, intestinal caseinolytic, stomach and intestinal amylase were significantly influenced by stachyose(P < 0.05). The highest values of trypsin and intestinal caseinolytic activities were observed in group S-1.25, while the highest activity of stomach amylase and the lowest activity of intestine amylase were observed in group S-5. No lesion or damage was found on the distal intestine structures of fish from all treatments, while the height of simple folds in the distal intestine was significantly increased(P< 0.05) when 1.25% or 2.5% stachyose was added in the diets. These results indicated that moderate level of stachyose(1.25%) improves the growth performance, feed utilization, digestive enzyme activities and the distal intestine structures of juvenile turbot.展开更多
Duplication cyst of the stomach with a pseudostratifie columnar ciliated epithelium is extremely rare.We de scribe two cases of these cysts,with emphasis on the immunophenotype and embryogenesis.The first patien was a...Duplication cyst of the stomach with a pseudostratifie columnar ciliated epithelium is extremely rare.We de scribe two cases of these cysts,with emphasis on the immunophenotype and embryogenesis.The first patien was a 29-year-old man who presented with crampin abdominal pain in his left lower quadrant.The secon patient was a 26-year-old woman who had a history over several years,of chronic epigastric abdominal pai radiating to her back.Both lesions were surgically re moved.They showed the same histomorphology.Th cysts were lined by a pseudostratified respiratory ep thelium with ciliated cells.The first cyst was connecte to the stomach,while the second cyst was not connect ed.Both cysts expressed thyroid transcription factor(TTF-1) and surfactant.In this report,we explore th possible embryogenesis of these lesions in the light o TTF-1 and surfactant expression.展开更多
基金Supported by the Science Research Project of Qingdao Technical College in 2012(12-A-2)~~
文摘[Objective] This study aimed to screen a bacterial strain capable of producing bioflocculant. [Method] A bacterial strain T-11 capable of producing bioflocculant was isolated from activated sludge. Detailed tests on the morphological, physiological and biochemical characteristics were carried out and identification was performed to identify the strain. Finally, the bioflocculant was isolated and purified, and the flocculating activity and chemical characteristics were measured. [Result] It was identified as Serratia plumuthica based on its morphological, physiological and biochemical characteristics. This strain secreted flocculant best in a culture medium which included sucrose and NaNO3. The maximal cell growth was achieved within 10 h and the flocculating activity paralleled to it. It was found to be effective for flocculation of kaolin suspension, when added at a final concentration of 0.7 mg/L, over a range of pHs （2-7）, and temperature （approximately 30-80 ℃）. Chemical analysis indicated that the bioflocculant was an acidic polysaccharide consisting of glucose, glucuronic acid and galactose, talose and altrose. Infrared spectrum analysis also revealed typical characteristics of polysaccharides. [Conclusion] The biofloccu- lants produced by strain T-11 can greatly improve the ability of activated sludge to settle.
基金supported by the Research Fund for the Doctoral Program of Higher Education of China(No.20120132120025)National Program on Key Basic Re-search Project(973 Program,2014CB138600)+1 种基金the Promotive Research Fund for Excellent Young and Middle-aged Scientists of Shandong Province(No.BS2013 SW007)Modern Agro-Industry Technology Research System(No.nycytx-50-G07)
文摘A 12-week feeding trial was conducted to evaluate the effects of dietary stachyose on the growth performance, digestive enzymes activities and intestinal structures of juvenile turbot(Scophthalmus maximus L). Five isonitrogenous(49.58% crude protein) and isolipidic(10.50% crude lipid) diets were formulated to contain 0(Control), 0.625%(S-0.625), 1.25%(S-1.25), 2.5%(S-2.5) and 5%(S-5) stachyose, respectively. With the increase of stachyose level, the growth performance and feed utilization of turbot, such as the specific growth rate, final mean body weight, weight gain rate and feed efficiency, increased significantly(P < 0.05) and then stabilized. The feed intake of fish fed S-5 was significantly higher(P < 0.05) than that of fish in other groups. The activities of trypsin, intestinal caseinolytic, stomach and intestinal amylase were significantly influenced by stachyose(P < 0.05). The highest values of trypsin and intestinal caseinolytic activities were observed in group S-1.25, while the highest activity of stomach amylase and the lowest activity of intestine amylase were observed in group S-5. No lesion or damage was found on the distal intestine structures of fish from all treatments, while the height of simple folds in the distal intestine was significantly increased(P< 0.05) when 1.25% or 2.5% stachyose was added in the diets. These results indicated that moderate level of stachyose(1.25%) improves the growth performance, feed utilization, digestive enzyme activities and the distal intestine structures of juvenile turbot.
文摘Duplication cyst of the stomach with a pseudostratifie columnar ciliated epithelium is extremely rare.We de scribe two cases of these cysts,with emphasis on the immunophenotype and embryogenesis.The first patien was a 29-year-old man who presented with crampin abdominal pain in his left lower quadrant.The secon patient was a 26-year-old woman who had a history over several years,of chronic epigastric abdominal pai radiating to her back.Both lesions were surgically re moved.They showed the same histomorphology.Th cysts were lined by a pseudostratified respiratory ep thelium with ciliated cells.The first cyst was connecte to the stomach,while the second cyst was not connect ed.Both cysts expressed thyroid transcription factor(TTF-1) and surfactant.In this report,we explore th possible embryogenesis of these lesions in the light o TTF-1 and surfactant expression.
