Stenotrophomonas sp. EGS12还原亚硒酸钠的条件优化及单质纳米硒的分离纯化撤回
作者：
袁志辉;吴永尧
期刊：
天然产物研究与开发 ,2019年 ISSN：1001-6880
作者机构：
湖南科技学院化学与生物工程学院;[袁志辉; 吴永尧] 湖南农业大学生物科学技术学院
摘要：
为进一步提高亚硒酸钠还原细菌Stenotrophomonas sp. EGS12的Na2SeO3还原效率，获得最佳还原条件。实验采用单因素试验和响应面分析法对其还原条件进行优化，结果显示pH值、温度对还原效率的影响为显著，而转速为极显著，经响应面法预测分析和实验验证，Stenotrophomonas sp. EGS12还原亚硒酸钠合成单质纳米硒的最佳条件为pH值为9，温度为35 ℃，转速为130 r/min，这三个因素对还原效率的影响是相对独立的。对还原产生的红色单质纳米硒颗粒进行分离纯化并采用扫描电镜和EDX分别分析其大小和元素组成。电镜扫描结果显示红色单质纳米硒颗粒大小为100～200 nm，EDX分析显示其中含有C、Se、O、P、S五种元素，其含量分别为61.23%、32.64%、4.52%、1.31%和0.3%。这些结果可为该菌株的进一步开发应用奠定基础。
语种：
中文
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甘露聚糖酶Man1602中的色氨酸修饰及其突变体性质的研究
作者：
雍婕;高晗;吴永尧;周海燕
期刊：
食品与生物技术学报 ,2019年38(4):45-49 ISSN：1673-1689
作者机构：
[雍婕; 高晗; 吴永尧; 周海燕] Hunan Agricultural University, College of Bioscience and Biotechnology, Changsha, 410128, China
关键词：
甘露聚糖酶;色氨酸;化学修饰;定点突变
摘要：
为了揭示色氨酸残基与Man1602酶活力的关系,提高Man1602的表达量,笔者通过研究色氨酸专一化学修饰剂与甘露聚糖酶Man1602的反应,同时根据甘露聚糖酶Man1602的序列比对结果,推测色氨酸残基与酶活的关系,对保守位点的色氨酸进行定点突变,检测各突变体酶的活力变化。结果表明,色氨酸为甘露聚糖酶Man1602的活性必需氨基酸,其中W196和W199位点的突变导致酶活几乎完全丧失,可以推断W196和W199为活性中心的氨基酸,W198也具有较高保守性,但对其突变并未造成酶的完全失活,推断W198是维持活性中心疏水性的重要氨基酸。
语种：
中文
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Biosynthesis of Selenium Nanoparticles by a Heavy Metal-Resistant Bacterium Stenotrophomonas sp EGS12
作者：
Yuan, Zhihui;Yong, Jie;Zhou, Haiyan* ;Wu, Yongyao*
期刊：
Nanoscience and Nanotechnology Letters ,2018年10(7):982-987 ISSN：1941-4900
通讯作者：
Zhou, Haiyan;Wu, Yongyao
作者机构：
[Zhou, Haiyan; Yuan, Zhihui; Wu, Yongyao; Zhou, HY; Wu, YY; Yong, Jie] Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Hunan, Peoples R China.;[Yuan, Zhihui] Hunan Univ Sci & Engn, Coll Chem & Bioengn, Yongzhou 425199, Peoples R China.;[Yuan, Zhihui] Hunan Prov Engn Res Ctr Ginkgo Biloba, Yongzhou 425199, Peoples R China.
通讯机构：
[Zhou, HY; Wu, YY] H;Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Hunan, Peoples R China.
关键词：
Selenium Nanoparticles;Biogenic Synthesis;Stenotrophomonas;Synthesis Mechanism
摘要：
Production of selenium nanoparticles (SeNPs) by chemical approaches is costly and environmentally hazardous, whereas biological methods, especially those using bacteria, can avoid these disadvantages. In this study, rapid biogenic synthesis of SeNPs by a heavy metal-resistant bacterium Stenotrophomonas sp., strain EGS12 was investigated. SeNPs were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). TEM and SEM analysis showed that the SeNPs were spherical and ranged from 100 to 200 nm in size. EDX demonstrated that the SeNPs contained C, Se, O, P, and S, and the content of Se was 32.64%. The mechanism of SeNPs biogenic synthesis by this strain was also investigated. The results documented that the biogenic synthesis of SeNPs, consisting of reduction of selenite to elemental selenium, was conducted synergistically by two reductases: nitrite reductase and thiol-mediated reductase. Thus, a novel pathway of efficient SeNP biosynthesis by a heavy metal-resistant Stenotrophomonas genus strain was identified.
语种：
英文
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甘露聚糖酶Man1602中的色氨酸修饰及其突变体性质的研究
作者：
雍婕;高晗;吴永尧;周海燕
作者机构：
[雍婕; 高晗; 吴永尧; 周海燕] 湖南农业大学生物科学技术学院
会议名称：
第十一届中国酶工程学术研讨会
会议时间：
2017-10-18
会议地点：
中国湖北武汉
关键词：
甘露聚糖酶;色氨酸;化学修饰;定点突变
摘要：
甘露聚糖酶是一种被广泛应用于医药、食品、饲料工业等领域的半纤维素酶。Man1602是本实验室自行筛选获得的高活力甘露聚糖酶,具有很强的纤维素降解能力。色氨酸是在酶活性中心出现频率较高的残基之一,经常作为活性中心的底物结合位点,在不少多糖水解酶的研究中都发现色氨酸与酶活密切相关。为揭示色氨酸残基与Man1602酶活力的关系,提高Man1602的表达量,本研究色氨酸专一化学修饰剂与甘露聚糖酶Man16
语种：
中文
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Mannanase man23 mutant library construction based on a novel cell-free protein expression system
作者：
Zhou, Haiyan;Yong, Jie;Gao, Han;Li, Tong;Xiao, Hongshi;...
期刊：
Journal of the Science of Food and Agriculture ,2017年97(7):2199-2204 ISSN：0022-5142
通讯作者：
Wu, Yongyao
作者机构：
[Zhou, Haiyan; Li, Tong; Wu, Yongyao; Gao, Han; Xiao, Hongshi; Yong, Jie] Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Wu, Yongyao] H;Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Hunan, Peoples R China.
关键词：
bacterial protein;beta mannosidase;Bacillus subtilis;chemistry;enzyme stability;enzymology;gene expression;gene library;genetics;kinetics;metabolism;molecular cloning;pH;temperature;Bacillus subtilis;Bacterial Proteins;beta-Mannosidase;Cloning, Molecular;Enzyme Stability;Gene Expression;Gene Library;Hydrogen-Ion Concentration;Kinetics;Temperature
摘要：
BACKGROUND: Mannanases are important enzymes which are widely used as a tool in agriculture and food industries. To improve the performance of mannanase Man23, a mutant library was created with rational design, and mutations were introduced on loops around the catalytic region. The Brevibacillus brevis B16 cell-free system which was created in this experiment provided the ability to express the mutant library efficiently. The activities of mutants were measured with a multi-volume spectrophotometer. RESULTS: The mutant Man1606 gained from this system is a sextet which has mutations of N146G, S147H, S156P, T157Y, Q206S and T249H simultaneously on loops 6, 8 and 10. Man1606 showed higher activity and stability thanMan23. The optimal temperature of Man1606 rose by 5°C (from 55 to 60°C) and the optimal pH increased slightly but its range became broader. CONCLUSION: This experiment demonstrated the B. brevis cell-free system shortens the expression time and is an efficient tool formannanase engineering. © 2016 Society of Chemical Industry.
语种：
英文
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复合菌液体发酵芝麻饼工艺研究
作者：
程益;雍婕;肖红仕;周海燕;吴永尧
期刊：
现代农业科技 ,2017年(1):250-252 ISSN：1007-5739
作者机构：
湖南农业大学生物科学技术学院,湖南长沙,410128;[肖红仕; 周海燕; 程益; 吴永尧; 雍婕] 湖南农业大学
关键词：
芝麻饼;复合菌;发酵条件;粗蛋白降解;粗脂肪降解
摘要：
探讨复合菌液体发酵芝麻饼发酵条件的优化,采用实验室筛选的高效蛋白质降解菌和高效脂肪降解菌混合发酵的方法,研究菌种比例、接种量、初始p H值、发酵温度、发酵时间、转速对发酵底物中蛋白质降解和脂肪降解的影响。结果表明：芝麻饼的最佳发酵工艺条件为高效蛋白质降解菌和高效脂肪降解菌的接种比例为2∶1,接种量5%,初始p H值7.0,发酵温度37℃,发酵时间48 h,转速为180 r/min。在此试验条件下,芝麻饼的粗蛋白质降解率为67.25%,粗脂肪的降解率为65.20%。
语种：
中文
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N-terminal truncation contributed to increasing thermal stability of mannanase Man1312 without activity loss
作者：
Zhou, Haiyan;Yang, Wenjiao;Tian, Yun;Peng, Hanhui;Wu, Yongyao*
期刊：
Journal of the Science of Food and Agriculture ,2016年96(4):1390-1395 ISSN：0022-5142
通讯作者：
Wu, Yongyao
作者机构：
[Peng, Hanhui; Zhou, Haiyan; Wu, Yongyao; Yang, Wenjiao] Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Hunan, Peoples R China.;[Tian, Yun] Hunan Agr Univ, Key Lab Agr Biochem & Biotransformat, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Wu, Yongyao] H;Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Hunan, Peoples R China.
关键词：
beta mannosidase;peptide fragment;amino acid sequence;chemical structure;chemistry;enzyme stability;gene deletion;genetics;heat;metabolism;molecular model;physiology;protein tertiary structure;structure activity relation;Amino Acid Sequence;beta-Mannosidase;Enzyme Stability;Hot Temperature;Models, Molecular;Molecular Structure;Peptide Fragments;Protein Structure, Tertiary;Sequence Deletion;Structure-Activity Relationship
摘要：
BACKGROUND: The disordered residues on distal loops affect the molecular structural stability and on some occasions have regulatory roles in catalytic reaction. To increase understanding of the influence of distal residue mutation, this study explored the thermostability and enzymatic activity of mannanase Man1312 deletion mutants. The focus was on residues located on the N-terminal region because they are more disordered and changeable. The effects of N-terminal truncation on enzymatic activity and thermal dynamics were investigated by spectrophotometry, circular dichroism and differential scanning calorimetry assays. RESULTS: The deletion mutants on V3, N7 and Q11 showed a marked increase in stability, while the enzymatic activity was significantly improved when triplet deletion was carried out. Triplet deletion MandVNQ showed around double the stability of its corresponding single-site and double-site deletion mutants. The Tm value of MandVNP was about 8°C higher than that of Man1312. MandVNP had improved characteristics of Topt by 10°C, t1/2 by 10min and catalytic activity by 11% in comparison with Man1312. Analysis of spectra and modeling showed that MandVNQ had increased helix and strand contents. CONCLUSION: N-terminal truncation had positive effects on the thermostability and activity of mannanase. © 2015 Society of Chemical Industry.
语种：
英文
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Loops Adjacent to Catalytic Region and Molecular Stability of Man1312
作者：
Zhou, Haiyan;Yong, Jie;Gao, Han;Yuan, Zhihui;Yang, Wenjiao;...
期刊：
Applied Biochemistry and Biotechnology ,2016年180(1):122-135 ISSN：0273-2289
通讯作者：
Wu, Yongyao
作者机构：
[Zhou, Haiyan; Yuan, Zhihui; Wu, Yongyao; Yang, Wenjiao; Gao, Han; Yong, Jie] Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Hunan, Peoples R China.;[Tian, Yun] Hunan Agr Univ, Key Lab Agr Biochem & Biotransformat, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Wu, Yongyao] H;Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Hunan, Peoples R China.
关键词：
Mannanase;Rational design;Loop;Molecular stability
摘要：
Hemicelluloses are the second major polysaccharides in nature and can be converted to ethanol product by a variety of enzymes including mannanases. Mannanase is an important enzyme that hydrolyses mannose-containing polysaccharides which are abundant in plants. An optimized mannanase could help to improve conversion process and make the technology efficiently and competitively. In this work, the effects of loops adjacent to active region on enzymic properties of Man1312 were investigated. Loop 6 and 10 are two loops neighboring to Man1312 catalytic region, and deletion mutagenesis and residue substitution were performed on both loops. Deletion on sites S145, Q148, N244, and S255 and substitution on sites N146, S147, S156, and T157 gave significant increased stability to enzyme. The quadruplet mutant ManD4I4 combined all the mutations and had higher optimal temperature and Tm value by 5 and 4°C than Man1312, respectively. From our data, we are able to conclude the loops of enzymes are important to design mutagenesis and obtain improved properties, especially the loops neighboring to catalytic region from tertiary structure. In our experiment, residue deletion and substitution on loops neighboring to catalytic region made significant improvement on enzyme properties. © 2016, Springer Science+Business Media New York.
语种：
英文
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芝麻饼残油量对其蛋白质降解的影响
作者：
程益;田云;杨文蛟;李童;周海燕;...
期刊：
化学与生物工程 ,2016年33(9):58-61 ISSN：1672-5425
作者机构：
湖南农业大学生物科学技术学院,湖南 长沙,410128;[杨文蛟; 田云; 周海燕; 程益; 吴永尧; 李童] 湖南农业大学
关键词：
芝麻饼;残油量;粗蛋白降解
摘要：
用实验室前期筛选得到的一株能降解芝麻饼粗蛋白的菌株 LQ 对不同残油量的芝麻饼进行发酵实验,分析了芝麻饼残油量对其粗蛋白降解的影响。结果表明：菌株 LQ 对残油量最低的芝麻饼5的降解效果最好,其蛋白酶活约为567.93 U·mL-1,蛋白质降解率约为51.89%,氨基酸转化率为13.27%,有机酸转化率为0.11%。随着芝麻饼中残油量的降低,粗蛋白含量提高,同时蛋白酶的活性也相应提高,粗蛋白的降解效果更好。
语种：
中文
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多种烟杆降解菌株的筛选及其协同作用比例优化
作者：
彭瀚辉;田云;李童;周海燕;吴永尧
期刊：
现代农业科技 ,2016年(11):225-227,231 ISSN：1007-5739
作者机构：
湖南农业大学生物科学技术学院,湖南长沙,410128;[田云; 周海燕; 吴永尧; 李童; 彭瀚辉] 湖南农业大学
关键词：
烟草;烟杆;纤维素酶;协同降解作用
摘要：
为了对废弃烟杆再利用,自行筛选到几种能够利用废弃烟杆进行高温好氧堆肥的高效微生物菌株,对分解出的几种菌株进行初步检测并对菌株协同作用的组合和配比做了进一步试验。结果表明,筛选获得的3组降解烟杆纤维素的菌株均能在以烟杆为唯一营养源的培养基上生长,且具有较强降解纤维素的能力,菌株编号分别为H2568、B1、M1。对这3种菌株的协同作用试验显示,H2568、B1、M1以1.0∶1.0∶1.5的生物量比例组合时具有最强的降解烟杆的能力,其纤维素降解率、半纤维素降解率、木质素降解率分别达到了56%、70%、33%,最高纤维素酶活力达到625.44 U/m L。
语种：
中文
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烟叶调理剂及其施用方式对烤烟产质量的影响
作者：
杨文蛟;周海燕;杨帆;彭瀚辉;黄李萍;...
期刊：
河南农业科学 ,2015年44(10):57-60 ISSN：1004-3268
作者机构：
[杨文蛟; 周海燕; 杨帆; 彭瀚辉; 黄李萍; 吴永尧] 湖南农业大学生物科学技术学院
关键词：
烤烟;烟叶调理剂;经济性状;化学成分
摘要：
为探讨施用烟叶调理剂对烤烟增香提质方面的作用效果,研究了烟叶调理剂喷叶2次与灌根+喷叶组合2种施用方式对烤烟产质量的影响。结果表明,增施烟叶调理剂总体上显著提高了烤烟单叶质量、产量、产值、均价、上等烟比例、中上等烟比例,烟叶调理剂喷叶及灌根+喷叶组合处理的上述指标较不施用调理剂处理分别提高3.71%、2.86%、6.82%、2.22%、5.89%、2.04%,3.07%、5.21%、5.17%、2.33%、3.02%、1.34%,但对初烤烟叶叶面积与叶厚度无明显影响。增施烟叶调理剂使烤后烟叶常规化学成分更为协调,烟叶调理剂喷叶2次处理效果更优。增施烟叶调理剂可以明显提高烤烟叶黄素、β-胡萝卜素、芸香苷含量。综合分析认为,增施烟叶调理剂对烟叶质量提升明显,其中喷叶2次施用效果优于灌根+喷叶组合施用方式。
语种：
中文
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油茶粕的固态发酵中试研究
作者：
聂旭;杨勇;王健;杨文蛟;杨凡;...
期刊：
江苏农业科学 ,2014年(5):222-223 ISSN：1002-1302
作者机构：
湖南农业大学生物科学技术学院,湖南长沙,410128;[聂旭; 杨凡; 杨文蛟; 杨勇; 吴永尧; 王健] 湖南农业大学
关键词：
中试;固态发酵;油茶饼粕
摘要：
利用对茶皂素具有降解作用的菌种对茶粕进行固体发酵,结果表明,菌种发酵原料茶粕的含水率只有6.2%,发酵开始堆肥含水率是50%,发酵后堆肥含水率仅15%。茶粕发酵后,粗蛋白含量增加,还原糖含量降低,发酵前后有机质含量变化不大。
语种：
中文
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油茶饼粕纤维素降解菌的筛选与鉴定
作者：
杨勇;聂旭;王健;杨帆;杨文蛟;...
期刊：
江苏农业科学 ,2014年(5):299-301 ISSN：1002-1302
作者机构：
湖南农业大学生物科学技术学院,湖南长沙,410128;[聂旭; 杨文蛟; 杨勇; 吴永尧; 杨帆; 王健] 湖南农业大学
关键词：
油茶饼粕;纤维素;还原糖;降解菌
摘要：
从土壤中筛选出酶活性相对较高且对油茶饼粕中的抑菌物质具有较高抗性的菌种YY-1、YY-2和YY-3,在此基础上测定它们的酶活性[5 843、1 4834、8 264 U/（mol·h）],并比较这3个菌种的生物量,最终确定YY-2为最佳菌种。通过菌种18S rDNA测序比对后发现,YY-2菌种与烟曲霉的相似性达99%。
语种：
中文
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1株亚硒酸钠还原菌的分离及初步研究
作者：
王健;袁志辉;聂旭;杨帆;杨勇;...
期刊：
江苏农业科学 ,2014年(10):370-372 ISSN：1002-1302
作者机构：
湖南农业大学生物科学技术学院,湖南长沙,410128;[袁志辉] 湖南农业大学生物科学技术学院，湖南长沙410128;湖南科技学院生命科学与化学工程系，湖南永州425100;[聂旭; 杨文蛟; 杨勇; 吴永尧; 杨帆; 王健] 湖南农业大学;[袁志辉] 湖南科技学院生命科学与化学工程系，湖南永州425100
关键词：
亚硒酸钠;亚硒酸盐;还原;寡养单胞菌
摘要：
从湖北恩施渔塘坝高硒土壤中分离筛选出1株能够还原Na2 SeO3的细菌EGS12,16S rDNA测序鉴定为嗜麦芽寡养单胞菌。开展Na2 SeO3对细菌菌株生长影响的试验研究,结果表明,该菌株在2 mmol/L Na2 SeO3的LB培养基中37℃摇床培养87 h,对Na2 SeO3的还原率为97.31%。
语种：
中文
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高效酒精酵母菌的选育及鉴定
作者：
李忠英;陈杰山;罗跃中;吴永尧
期刊：
食品研究与开发 ,2014年(7):104-107 ISSN：1005-6521
作者机构：
[罗跃中; 李忠英; 陈杰山] 湖南化工职业技术学院;湖南农业大学生物科学技术学院;[吴永尧] 湖南农业大学
关键词：
耐高温酵母;筛选;鉴定;酒精发酵
摘要：
从各种腐败水果、葡萄园里土壤等不同基质中筛选分离得到144株酵母菌,采用耐热、耐酒精处理方法,结合TTC法初筛和复筛试验得到一株酒精发酵的高产酵母菌株,编号为TJ-18。研究结果表明,该菌糖利用率较高,且发酵力突出,40℃培养72 h,CO2失重为10.4 g,酒精产率最高可达5.9%（体积分数）。对其形态及特征做了常规鉴定实验,根据生理生化试验结果,并对照《TheYeast》对酵母的描述,确定TJ-18为酵母属的酿酒酵母（Saccharomyces cerevisiae）。
语种：
中文
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土壤微生物分离新技术的研究进展
作者：
袁志辉;王健;杨文蛟;吴永尧
期刊：
土壤学报 ,2014年51(6):1183-1191 ISSN：0564-3929
作者机构：
[袁志辉; 杨文蛟; 吴永尧; 王健] 湖南农业大学生物科学技术学院,长沙410000;[袁志辉] 湖南科技学院生命科学与化学工程系,湖南永州 425199
关键词：
土壤微生物;未培养微生物;分离新技术
摘要：
土壤是环境微生物学研究中最具挑战性的环境,也是生物分子、遗传资源开发的热点区域。在"宏-组学"方法快速发展的今天,土壤微生物分离培养技术在微生物环境功能研究、代谢途径的阐明、特定功能的验证及基础实验和生产实践的应用等方面仍然发挥着重要作用。本文首先分析了大多数环境微生物不能被分离培养的几个原因。然后重点综述了近年来在土壤微生物分离培养技术方面的探索,主要包括生长培养基的优化和重新设计如培养基稀释分离、添加生长限制因子、更换凝固剂等,在延长培养时间、改善含氧量、降低培养温度等方面对生长条件进行改进,采用"扩散盒"、"原位培养陷阱"等技术对微生物进行天然环境原位培养,对环境微生物群体培养和共培养,利用"宏基因组学""宏蛋白质组学"等非培养技术辅助分离等。最后,作者对未来土壤微生物分离研究的方向提出了自己的建议。
语种：
中文
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四种魔芋中神经酰胺含量比较研究
作者：
周浩;王健;聂旭;谭军;吴永尧
期刊：
化学与生物工程 ,2013年30(4):83-85 ISSN：1672-5425
作者机构：
湖南农业大学生物科学技术学院,湖南长沙,410128;[聂旭; 周浩; 吴永尧; 谭军; 王健] 湖南农业大学
关键词：
魔芋;神经酰胺
摘要：
利用HPLC-ELSD法测定了4种魔芋中的神经酰胺含量.结果表明,4种魔芋中的神经酰胺含量呈现种间差异,其中神经酰胺含量最高的是M4,为43.75 μg· g-1.
语种：
中文
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Comparison of expression systems for the extracellular production of mannanase Man23 originated from Bacillus subtilis B23
作者：
Zhou, Haiyan;Yang, Yong;Nie, Xu;Yang, Wenjiao;Wu, Yongyao*
期刊：
Microbial Cell Factories ,2013年12(1):1-10 ISSN：1475-2859
通讯作者：
Wu, Yongyao
作者机构：
[Zhou, Haiyan; Wu, Yongyao; Yang, Wenjiao; Nie, Xu; Yang, Yong] Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Wu, Yongyao] H;Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Hunan, Peoples R China.
关键词：
Mannanase;Recombinant gene;Host bacterium;Expression system
摘要：
Background: Mannanase is an enzyme that can catalyze random hydrolysis of beta-1,4-mannosidic linkages in the main chain of mannans, glucomannans and galactomannans which are the key polymers in hemicellulose. It has been used in a number of different industrial applications including food, feed, pharmaceutical, pulp/paper industries, and second generation biofuel. To optimize the expression system of mannanase Man23 gene, two kinds of vectors and host bacteria were determined and compared.Results: Recombinants pHY-p43-man23 and pBPS-man23 were constructed and transferred into Bacillus subtilis WB600 and Brevibacillus brevis respectively. For mannanase Man23 gene, recombinant pHY-p43-man23 expressed in Brevibacillus brevis had higher production and activity. Compared to the wild-type Bacillus subtilis B23, the production of recombinant pHY-p43-man23 in B. brevis increased by 10 times and activity increased by 21.3%. pHY-p43-man23 in B. brevis had activity at the range of 20 ~ 70°C but its optimum temperature was 50°C and had activity from pH 4 ~ 10 but its optimum pH was around 7. This demonstrated the recombinant had improved stability as well.Conclusions: Mannanase is an important industrial enzyme and combination of vector pHY-p43 and host Brevibacillus brevis is a novel expression system for a mannanase decoding gene. This work aims at exploring a better expression system of mannanase Man23 decoding gene for industrial application. © 2013 Zhou et al.; licensee BioMed Central Ltd.
语种：
英文
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Analysis of the Interaction of Tarantula Toxin Jingzhaotoxin-III (β-TRTX-Cj1α) with the Voltage Sensor of Kv2.1 Uncovers the Molecular Basis for Cross-Activities on Kv2.1 and Nav1.5 Channels
作者：
Tao, Huai;Chen, Jin J.;Xiao, Yu C.;Wu, Yuan Y.;Su, Hai B.;...
期刊：
BIOCHEMISTRY ,2013年52(42):7439-7448 ISSN：0006-2960
通讯作者：
Liang, SP
作者机构：
[Wang, Heng Y.; Li, Dan; Liang, Song P.; Liu, Zhong H.; Wu, Yuan Y.; Su, Hai B.; Xiao, Yu C.; Wang, Mei C.; Tao, Huai; Liang, SP] Hunan Normal Univ, Coll Life Sci, Key Lab Prot Chem & Dev Biol, Minist Educ, Changsha 410081, Hunan, Peoples R China.;[Tao, Huai] Hunan Univ Chinese Med, Dept Biochem & Mol Biol, Changsha 410208, Hunan, Peoples R China.;[Chen, Jin J.] Hunan Agr Univ, Coll Biol Sci & Technol, Changsha 410128, Hunan, Peoples R China.;[Deng, Mel C.] Cent S Univ, Sch Biol Sci & Technol, Dept Biochem, Changsha 410013, Hunan, Peoples R China.
通讯机构：
[Liang, SP ] H;Hunan Normal Univ, Coll Life Sci, Key Lab Prot Chem & Dev Biol, Minist Educ, Changsha 410081, Hunan, Peoples R China.
摘要：
Animal venoms contain a fascinating array of divergent peptide toxins that have cross-activities on different types of voltage-gated ion channels. However, the underlying mechanism remains poorly understood. Jingzhaotoxin-III (JZTX-III), a 36-residue peptide from the tarantula Chilobrachys jingzhao, is specific for Nav1.5 and Kv2.1 channels over the majority of other ion channel subtypes. JZTX-III traps the Nav1.5 DII voltage sensor at closed state by binding to the DIIS3-S4 linker. In this study, electrophysiological experiments showed that JZTX-III had no effect on five voltage-gated potassium channel subtypes (Kv1.4, Kv3.1, and Kv4.1-4.3), whereas it significantly inhibited Kv2.1 with an IC50 of 0.71 ± 0.01 μM. Mutagenesis and modeling data suggested that JZTX-III docks at the Kv2.1 voltage-sensor paddle. Alanine replacement of Phe274, Lys280, Ser281, Leu283, Gln284, and Val288 could decrease JZTX-III affinity by 7-, 9-, 34-, 12-, 9-, and 7-fold, respectively. Among them, S281 is the most crucial determinant, and the substitution with Thr only slightly reduced toxin sensitivity. In contrast, a single conversion of Ser281 to Ala, Phe, Ile, Val, or Glu increased the IC50 value by >34-fold. Alanine-scanning mutagenesis experiments indicated that the functional surface of JZTX-III bound to the Kv2.1 channel is composed of four hydrophobic residues (Trp8, Trp28, Trp30, and Val33) and three charged residues (Arg13, Lys15, and Glu34). The bioactive surfaces of JZTX-III interacting with Kv2.1 and Nav1.5 are only partially overlapping. These results strongly supported the hypothesis that animal toxins might use partially overlapping bioactive surfaces to target the voltage-sensor paddles of two different types of ion channels. Increasing our understanding of the molecular mechanisms of toxins interacting with voltage-gated sodium and potassium channels may provide new molecular insights into the design of more potent ion channel inhibitors. © 2013 American Chemical Society.
语种：
英文
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3种魔芋葡甘聚糖理化特性的比较研究
作者：
郭晟;李磊;周浩;林元山;吴永尧
期刊：
湖南农业科学 ,2012年(09):95-98 ISSN：1006-060X
作者机构：
湖南农业大学生物科学技术学院,湖南 长沙,410128;[李磊; 郭晟; 周浩; 吴永尧; 林元山] 湖南农业大学
关键词：
魔芋;葡甘聚糖;含量;黏度;溶胀度;单糖
摘要：
试验研究了白魔芋、花魔芋、珠芽魔芋中葡甘聚糖的含量、溶液稳定性、精粉黏度、溶胀度及单糖组成成分比例的差异。结果表明,葡甘聚糖黏度的大小顺序是:花魔芋>珠芽魔芋>白魔芋;葡甘聚糖含量的大小顺序是:花魔芋>白魔芋>珠芽魔芋;葡甘聚糖水解单糖比大小顺序是:花魔芋>珠芽魔芋>白魔芋。
语种：
中文
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