聚唾液酸(PSA)是一种具有重要生物功能的高分子多糖,广泛存在于自然界和人体中。由于其低免疫原性和良好的生物降解性,PSA被认为是一种理想的药物控释材料。本研究以大肠杆菌K87为出发菌株,通过过表达Neu5AC合成路径中的关键基因neuD,...聚唾液酸(PSA)是一种具有重要生物功能的高分子多糖,广泛存在于自然界和人体中。由于其低免疫原性和良好的生物降解性,PSA被认为是一种理想的药物控释材料。本研究以大肠杆菌K87为出发菌株,通过过表达Neu5AC合成路径中的关键基因neuD,构建了高效合成PSA的基因工程菌株。通过摇瓶发酵和发酵罐发酵实验,验证了不同拷贝数neuD基因对PSA产量的影响。结果表明,高拷贝数表达载体能显著提高PSA的产量,其中E. coli K87-6菌株在5 L发酵罐中PSA产量达8.4 g/L,比出发菌株提高27%。本研究构建的高效合成PSA的基因工程菌株在工业生产中具有广泛的应用前景。Polysialic acid (PSA) is a high-molecular-weight polysaccharide with significant biological functions, widely found in nature and the human body. Due to its low immunogenicity and good biodegradability, PSA is considered an ideal material for drug delivery systems. In this study, Escherichia coli K87 was used as the starting strain to construct genetically engineered strains for efficient PSA production by overexpressing the key gene neuD in the Neu5AC synthesis pathway. The effects of different copy numbers of the neuD gene on PSA yield were verified through shake flask and fermenter experiments. The results showed that high-copy-number expression vectors significantly increased PSA yield, with the E. coli K87-6 strain achieving a PSA yield of 8.4 g/L in a 5 L fermenter, which is 27% higher than the starting strain. The genetically engineered strains constructed in this study have broad application prospects in industrial production.展开更多
5-HT1A基因编码5-羟色胺(血清素)的G蛋白偶联受体(属于5-羟色胺受体亚家族)。C-1019G多态位点是5-HT1A基因启动子区一个重要的功能性多态位点,人群中存在3种基因型即CC、CG、GG,它与个体的恋爱关系及抑郁症、焦虑症等精神疾病密切相关...5-HT1A基因编码5-羟色胺(血清素)的G蛋白偶联受体(属于5-羟色胺受体亚家族)。C-1019G多态位点是5-HT1A基因启动子区一个重要的功能性多态位点,人群中存在3种基因型即CC、CG、GG,它与个体的恋爱关系及抑郁症、焦虑症等精神疾病密切相关。本文对5-HT1A基因C-1019G多态位点的相关机制、检测方法、研究进展等进行综述。The 5-HT1A gene encodes a G protein-coupled receptor for serotonin, which belongs to the 5-hydroxytryptamine receptor subfamily. C-1019G polymorphism is an important functional poly-morphism in the promoter region of 5-HT1A gene. There are three genotypes (CC, CG and GG) in the population, which are closely related to individual’s romantic relationship and mental disorders such as depression and anxiety. In this paper, the mechanism, detection methods and research progress of C-1019G polymorphism of 5-HT1A gene were reviewed.展开更多
采用高效液相色谱法测定四种植物多糖的单糖组成。用超声辅助提取大豆、香菇、木耳、枸杞多糖,通过三氟乙酸水解后,用1-苯基-3-甲基-5-吡唑啉酮(PMP)柱前衍生–液相色谱法检测,并选用专属性,精密度,灵敏度,线性范围和加标回收率对此方...采用高效液相色谱法测定四种植物多糖的单糖组成。用超声辅助提取大豆、香菇、木耳、枸杞多糖,通过三氟乙酸水解后,用1-苯基-3-甲基-5-吡唑啉酮(PMP)柱前衍生–液相色谱法检测,并选用专属性,精密度,灵敏度,线性范围和加标回收率对此方法进行验证,最后对大豆、香菇、木耳、枸杞多糖中单糖的组成进行分析。结果表明,待测定的各单糖组分在1.03~550 μg/mL范围内呈良好的线性关系,且各组分分离度大于1.5,检出限大于2.01 μg/mL,定量限大于6.43 μg/mL,精密度与稳定性的相对标准偏差均小于4%,加标回收率在98.0%~101.4%之间,验证结果显示该方法简单快速、准确可靠。通过应用此方法测定大豆、香菇、木耳、枸杞多糖的单糖组成,结果显示大豆多糖属于以半乳糖为主的杂多糖,且半乳糖含量为53.40%;香菇和枸杞多糖属于以葡萄糖为主的杂多糖,所含的葡萄糖含量分别为45.74%和21.07%;木耳多糖属于以D-甘露糖为主的杂多糖,且D-甘露糖含量为18.64%。The monosaccharide compositions of four plant polysaccharides were determined by high performance liquid chromatography (HPLC). Polysaccharides from soybeans, shiitake mushrooms, black fungi, and wolfberries were extracted by ultrasonic assistance. After hydrolysis with trifluoroacetic acid, the samples were detected by pre-column derivatization with 1-phenyl-3-methyl-5-pyrazolone (PMP) and HPLC. The method was validated using specificity, precision, sensitivity, linear range, and standard addition recovery rate. Finally, the monosaccharide compositions in polysaccharides from soybeans, shiitake mushrooms, black fungi, and wolfberries were analyzed. The results showed that the monosaccharide components to be determined showed a good linear relationship in the range of 1.03~550 μg/mL, and the resolution of each component was greater than 1.5, the detection limit was greater than 2.01 μg/mL, and the limit of quantification was greater than 6.43 μg/mL. The relative standard deviation of precision and stability was less than 4%, and the recovery of standard addition was between 98.0%~101.4%. The verification results show that the method is simple, rapid, accurate and reliable. The monosaccharide composition of soybean, shiitake mushroom, fungus and medlar polysaccharide was determined by applying this method. The results showed that soybean polysaccharide belongs to galactose-based heteropolysaccharide and the galactose content was 53.40%. The heteropolysaccharide contained 45.74% and 21.07%, respectively;the fungus polysaccharide belonged to D-mannose-based heteropolysaccharide, and the D-mannose content was 18.64%.展开更多
使用玉米淀粉作为原料,通过复合酶法成功制备了具有优良特性的多孔淀粉,并对其理化性质进行了详细分析。研究结果显示,在最佳的酶解条件下,酶配比为1:3 (g/g)、酶用量为3%、底物浓度为25%、酶解时间为8 h、酶解温度为45℃、以及pH值为5....使用玉米淀粉作为原料,通过复合酶法成功制备了具有优良特性的多孔淀粉,并对其理化性质进行了详细分析。研究结果显示,在最佳的酶解条件下,酶配比为1:3 (g/g)、酶用量为3%、底物浓度为25%、酶解时间为8 h、酶解温度为45℃、以及pH值为5.5时得到的多孔淀粉展现出了较高的吸油率(189.56%)、较大的比容积(2.13 cm³/g)、合适的溶解率(13.17%)以及显著的膨胀力(3.63 g/g),这些指标均明显优于原始淀粉。扫描电子显微镜(SEM)的观察进一步证实了多孔淀粉颗粒的完整性和表面的蜂窝状微孔结构,孔径和深度均处于理想状态,所制备的多孔淀粉具有广泛的潜在应用价值。Using corn starch as raw material, porous starch with excellent properties was successfully prepared by compound enzymatic method, and its physicochemical properties were analyzed in detail. The results showed that under the optimal enzymatic hydrolysis conditions, the porous starch obtained at the enzyme ratio of 1:3 (g/g), the enzyme dosage of 3%, the substrate concentration of 25%, the enzymatic hydrolysis time of 8 h, the enzymatic hydrolysis temperature of 45˚C, and the pH value of 5.5 showed higher oil absorption rate (189.56%), larger specific volume (2.13 cm³/g), suitable solubility (13.17%) and significant swelling force (3.63 g/g), which were significantly better than those of the original starch. The observation of scanning electron microscopy (SEM) further confirmed the integrity of porous starch granules, the honeycomb microporous structure on the surface, and the pore size and depth were in an ideal state, and the prepared porous starch has a wide range of potential application value.展开更多
自然界空气中的微生物对人类生活和健康有着广泛影响。2003年暴发的重症急性呼吸综合症(SARS)、2009年的H1N1、2013年在我国首次发现的H7N9以及2019年爆发的新冠肺炎疫情使得全世界开始更加关注空气传染性疾病的传播。在多种疾病的传播...自然界空气中的微生物对人类生活和健康有着广泛影响。2003年暴发的重症急性呼吸综合症(SARS)、2009年的H1N1、2013年在我国首次发现的H7N9以及2019年爆发的新冠肺炎疫情使得全世界开始更加关注空气传染性疾病的传播。在多种疾病的传播方式中,空气传播具有传播途径易实现、传播广泛、发病率高等特点,而其中的生物气溶胶传播更是因其在空气颗粒物中所占比例小,可通过呼吸道、皮肤和消化道进入人体,引起感染、过敏性疾病和中毒等特点更加难以预防。所以对空气中病原体的实时监测和预警成为控制疫情传播的关键。本文主要总结了国内外关于微生物气溶胶采样技术及设备研究进展,尤其是在微生物气溶胶粒度分离与浓缩采样技术方面,结合研究现状,提出改进措施。Microorganisms in the air of nature have a wide range of effects on human life and health. The outbreak of severe acute respiratory syndrome (SARS) in 2003, H1N1 in 2009, the first discovery of H7N9 in China in 2013, and the sudden outbreak of COVID-19 this year have raised global concerns about the transmission of air infectious diseases. Among the transmission modes of various diseases, airborne transmission is characterized by easy realization of transmission routes, wide range of transmission, and high incidence rate. Among them, the biological aerosol transmission is even more difficult to prevent due to its small proportion in air particles, which can enter the human body through the respiratory tract, skin, and digestive tract, causing infection, allergic diseases, and poisoning. Therefore, the real-time monitoring and early warning of pathogens in the air become the key to controlling the spread of the epidemic. This paper summarizes the research progress of biological aerosol sampling technology and equipment in domestic and overseas, especially in the aspect of particle separation and concentration sampling technology of biological aerosol. Combined with the research status, the improvement measures and development advantages are proposed.展开更多
文摘聚唾液酸(PSA)是一种具有重要生物功能的高分子多糖,广泛存在于自然界和人体中。由于其低免疫原性和良好的生物降解性,PSA被认为是一种理想的药物控释材料。本研究以大肠杆菌K87为出发菌株,通过过表达Neu5AC合成路径中的关键基因neuD,构建了高效合成PSA的基因工程菌株。通过摇瓶发酵和发酵罐发酵实验,验证了不同拷贝数neuD基因对PSA产量的影响。结果表明,高拷贝数表达载体能显著提高PSA的产量,其中E. coli K87-6菌株在5 L发酵罐中PSA产量达8.4 g/L,比出发菌株提高27%。本研究构建的高效合成PSA的基因工程菌株在工业生产中具有广泛的应用前景。Polysialic acid (PSA) is a high-molecular-weight polysaccharide with significant biological functions, widely found in nature and the human body. Due to its low immunogenicity and good biodegradability, PSA is considered an ideal material for drug delivery systems. In this study, Escherichia coli K87 was used as the starting strain to construct genetically engineered strains for efficient PSA production by overexpressing the key gene neuD in the Neu5AC synthesis pathway. The effects of different copy numbers of the neuD gene on PSA yield were verified through shake flask and fermenter experiments. The results showed that high-copy-number expression vectors significantly increased PSA yield, with the E. coli K87-6 strain achieving a PSA yield of 8.4 g/L in a 5 L fermenter, which is 27% higher than the starting strain. The genetically engineered strains constructed in this study have broad application prospects in industrial production.
文摘5-HT1A基因编码5-羟色胺(血清素)的G蛋白偶联受体(属于5-羟色胺受体亚家族)。C-1019G多态位点是5-HT1A基因启动子区一个重要的功能性多态位点,人群中存在3种基因型即CC、CG、GG,它与个体的恋爱关系及抑郁症、焦虑症等精神疾病密切相关。本文对5-HT1A基因C-1019G多态位点的相关机制、检测方法、研究进展等进行综述。The 5-HT1A gene encodes a G protein-coupled receptor for serotonin, which belongs to the 5-hydroxytryptamine receptor subfamily. C-1019G polymorphism is an important functional poly-morphism in the promoter region of 5-HT1A gene. There are three genotypes (CC, CG and GG) in the population, which are closely related to individual’s romantic relationship and mental disorders such as depression and anxiety. In this paper, the mechanism, detection methods and research progress of C-1019G polymorphism of 5-HT1A gene were reviewed.
文摘采用高效液相色谱法测定四种植物多糖的单糖组成。用超声辅助提取大豆、香菇、木耳、枸杞多糖,通过三氟乙酸水解后,用1-苯基-3-甲基-5-吡唑啉酮(PMP)柱前衍生–液相色谱法检测,并选用专属性,精密度,灵敏度,线性范围和加标回收率对此方法进行验证,最后对大豆、香菇、木耳、枸杞多糖中单糖的组成进行分析。结果表明,待测定的各单糖组分在1.03~550 μg/mL范围内呈良好的线性关系,且各组分分离度大于1.5,检出限大于2.01 μg/mL,定量限大于6.43 μg/mL,精密度与稳定性的相对标准偏差均小于4%,加标回收率在98.0%~101.4%之间,验证结果显示该方法简单快速、准确可靠。通过应用此方法测定大豆、香菇、木耳、枸杞多糖的单糖组成,结果显示大豆多糖属于以半乳糖为主的杂多糖,且半乳糖含量为53.40%;香菇和枸杞多糖属于以葡萄糖为主的杂多糖,所含的葡萄糖含量分别为45.74%和21.07%;木耳多糖属于以D-甘露糖为主的杂多糖,且D-甘露糖含量为18.64%。The monosaccharide compositions of four plant polysaccharides were determined by high performance liquid chromatography (HPLC). Polysaccharides from soybeans, shiitake mushrooms, black fungi, and wolfberries were extracted by ultrasonic assistance. After hydrolysis with trifluoroacetic acid, the samples were detected by pre-column derivatization with 1-phenyl-3-methyl-5-pyrazolone (PMP) and HPLC. The method was validated using specificity, precision, sensitivity, linear range, and standard addition recovery rate. Finally, the monosaccharide compositions in polysaccharides from soybeans, shiitake mushrooms, black fungi, and wolfberries were analyzed. The results showed that the monosaccharide components to be determined showed a good linear relationship in the range of 1.03~550 μg/mL, and the resolution of each component was greater than 1.5, the detection limit was greater than 2.01 μg/mL, and the limit of quantification was greater than 6.43 μg/mL. The relative standard deviation of precision and stability was less than 4%, and the recovery of standard addition was between 98.0%~101.4%. The verification results show that the method is simple, rapid, accurate and reliable. The monosaccharide composition of soybean, shiitake mushroom, fungus and medlar polysaccharide was determined by applying this method. The results showed that soybean polysaccharide belongs to galactose-based heteropolysaccharide and the galactose content was 53.40%. The heteropolysaccharide contained 45.74% and 21.07%, respectively;the fungus polysaccharide belonged to D-mannose-based heteropolysaccharide, and the D-mannose content was 18.64%.
文摘使用玉米淀粉作为原料,通过复合酶法成功制备了具有优良特性的多孔淀粉,并对其理化性质进行了详细分析。研究结果显示,在最佳的酶解条件下,酶配比为1:3 (g/g)、酶用量为3%、底物浓度为25%、酶解时间为8 h、酶解温度为45℃、以及pH值为5.5时得到的多孔淀粉展现出了较高的吸油率(189.56%)、较大的比容积(2.13 cm³/g)、合适的溶解率(13.17%)以及显著的膨胀力(3.63 g/g),这些指标均明显优于原始淀粉。扫描电子显微镜(SEM)的观察进一步证实了多孔淀粉颗粒的完整性和表面的蜂窝状微孔结构,孔径和深度均处于理想状态,所制备的多孔淀粉具有广泛的潜在应用价值。Using corn starch as raw material, porous starch with excellent properties was successfully prepared by compound enzymatic method, and its physicochemical properties were analyzed in detail. The results showed that under the optimal enzymatic hydrolysis conditions, the porous starch obtained at the enzyme ratio of 1:3 (g/g), the enzyme dosage of 3%, the substrate concentration of 25%, the enzymatic hydrolysis time of 8 h, the enzymatic hydrolysis temperature of 45˚C, and the pH value of 5.5 showed higher oil absorption rate (189.56%), larger specific volume (2.13 cm³/g), suitable solubility (13.17%) and significant swelling force (3.63 g/g), which were significantly better than those of the original starch. The observation of scanning electron microscopy (SEM) further confirmed the integrity of porous starch granules, the honeycomb microporous structure on the surface, and the pore size and depth were in an ideal state, and the prepared porous starch has a wide range of potential application value.
文摘自然界空气中的微生物对人类生活和健康有着广泛影响。2003年暴发的重症急性呼吸综合症(SARS)、2009年的H1N1、2013年在我国首次发现的H7N9以及2019年爆发的新冠肺炎疫情使得全世界开始更加关注空气传染性疾病的传播。在多种疾病的传播方式中,空气传播具有传播途径易实现、传播广泛、发病率高等特点,而其中的生物气溶胶传播更是因其在空气颗粒物中所占比例小,可通过呼吸道、皮肤和消化道进入人体,引起感染、过敏性疾病和中毒等特点更加难以预防。所以对空气中病原体的实时监测和预警成为控制疫情传播的关键。本文主要总结了国内外关于微生物气溶胶采样技术及设备研究进展,尤其是在微生物气溶胶粒度分离与浓缩采样技术方面,结合研究现状,提出改进措施。Microorganisms in the air of nature have a wide range of effects on human life and health. The outbreak of severe acute respiratory syndrome (SARS) in 2003, H1N1 in 2009, the first discovery of H7N9 in China in 2013, and the sudden outbreak of COVID-19 this year have raised global concerns about the transmission of air infectious diseases. Among the transmission modes of various diseases, airborne transmission is characterized by easy realization of transmission routes, wide range of transmission, and high incidence rate. Among them, the biological aerosol transmission is even more difficult to prevent due to its small proportion in air particles, which can enter the human body through the respiratory tract, skin, and digestive tract, causing infection, allergic diseases, and poisoning. Therefore, the real-time monitoring and early warning of pathogens in the air become the key to controlling the spread of the epidemic. This paper summarizes the research progress of biological aerosol sampling technology and equipment in domestic and overseas, especially in the aspect of particle separation and concentration sampling technology of biological aerosol. Combined with the research status, the improvement measures and development advantages are proposed.
