细菌细胞壁的组成结构

细菌细胞壁的组成结构 细胞壁的观察方法: ? 质壁分离，染色 ? 电镜观察 G，与Gˉ细菌cw的模式结构 ?共有组分— 肽聚糖 ?特有组分— G， 磷壁酸 Gˉ 脂多糖 细胞壁是位于菌体的外层，内侧紧贴细胞膜的一层无色透明，坚韧而有弹性的结构。细胞壁约占细胞干重的10%—25%。 细胞壁是位于菌体的外层，内侧紧贴细胞膜的一层无色透明，坚韧而有弹性的结构。细胞壁约占细胞干重的10%—25%。 概念: 肽聚糖是由N—乙酰胞壁酸(NAM)和N—乙酰葡糖胺(NAG)以及短肽链(主要是四肽)组成的亚单位聚合而成的大分子聚合物。 rAt present, we have formed a "three-three" Park. …… Industrial Park, according to ... ... The instructions of comrade, focus on development needs in the next decade, based on the original, and then extended the 6 square kilometers. Of the Park, to further improve the roads, power supply, communications, water supply and drainage and sewage pipe network and other infrastructure, to achieve full coverage of infrastructure and interconnection with the facilities and raise capacity. Each park to determine 1 leading industries, in particular stone Materials, cans, gloves, through guided, force and other measures to promote the "road company" Park, industrial agglomeration. Currently, to focus on building better ... ... Industrial Park, ... ... Wood Park as the starting area of the industrial park, planners need to take out plan, start construction as soon as possible, undertake in a timely manner ... ... Transfer of the wood industry. This opportunity slip by, so the timing must be tight. Second is to optimize government service. Low efficiency of government services, departments do not coordinate the views of businesses large, poor business environment, it is ... ... Short Board, decide to change. We will continue to deepen reform of the administrative examination and approval system, good digestion, implement the Government canceled, adjustment and devolution of administrative examination and approval matters, strengthen the existing supervision in matters of administrative power, has made it clear to cancel, are not allowed to keep or disguised approval. To do list list of administrative powers and responsibilities (1)细胞壁的基本骨架——肽聚糖(共有成分) 肽聚糖网格状结构 ,2,G+菌的细胞壁 肽聚糖(peptidoglycan): 磷壁酸(teichoic acid) 细胞壁厚度 较厚，20~30nm 细胞壁分层 不分层 肽聚糖含量 含量高(30-70) 肽聚糖层数 层数多 rAt present, we have formed a "three-three" Park. …… Industrial Park, according to ... ... The instructions of comrade, focus on development needs in the next decade, based on the original, and then extended the 6 square kilometers. Of the Park, to further improve the roads, power supply, communications, water supply and drainage and sewage pipe network and other infrastructure, to achieve full coverage of infrastructure and interconnection with the facilities and raise capacity. Each park to determine 1 leading industries, in particular stone Materials, cans, gloves, through guided, force and other measures to promote the "road company" Park, industrial agglomeration. Currently, to focus on building better ... ... Industrial Park, ... ... Wood Park as the starting area of the industrial park, planners need to take out plan, start construction as soon as possible, undertake in a timely manner ... ... Transfer of the wood industry. This opportunity slip by, so the timing must be tight. Second is to optimize government service. Low efficiency of government services, departments do not coordinate the views of businesses large, poor business environment, it is ... ... Short Board, decide to change. We will continue to deepen reform of the administrative examination and approval system, good digestion, implement the Government canceled, adjustment and devolution of administrative examination and approval matters, strengthen the existing supervision in matters of administrative power, has made it clear to cancel, are not allowed to keep or disguised approval. To do list list of administrative powers and responsibilities 交联度 交联度高 磷壁酸 有 脂多糖 无 DAP 无 肽聚糖:含量高，占壁重的30~70% ;不同菌种中肽聚糖(肽链)组分不同,具重要分类意义 ? 革兰氏阳性细菌肽聚糖(peptidoglycan)的结构 (幻灯片015.016.017.018)以Staphylococcus aureus为代。肽聚糖层厚度为20~80nm，由约40层网状分子组成。网状的肽聚糖大分子是由大量小分子单体聚合而成的。每一肽聚糖单体含有三个组成部分: a) 双糖单位，N-乙酰葡萄糖胺与N-乙酰胞壁酸分子通过B-1，4-糖苷键连接而成; b) 短肽尾，由四个氨基酸连起来的短肽连接在N-乙酰胞壁酸分子上。这四个氨基酸是L-丙氨酸-D-谷氨酸-L-赖氨酸-D-丙氨酸; c) 肽桥，S. Aureus的肽桥为甘氨酸五肽。肽桥的氨基端与前一肽聚糖链中一个肽尾的第四氨基酸——D-丙氨酸的羧基相连接，而它的羧基端则与相邻的肽聚糖链中一个肽尾的第三氨基酸——碱性氨基酸L-赖氨酸的氨基相连接，从而使前后两个肽聚糖链交联起来。 溶菌酶:A. Fleming，1922年发现，存在于卵清、人的泪液和鼻涕、部分细菌和噬菌体内，能有效地水解细菌肽聚糖，作用于肽聚糖骨架上的N-乙酰胞壁酸的C1与N-乙酰葡糖胺C4之间的B-1，4-糖苷键。 Gram positive cells have only two layers, the cytoplasmic membrane and a THICK LAYER of peptidoglycan as the outermost component. 磷壁酸teichoic acid(垣酸) 占壁干重40~50%。是以磷酸多元醇分子的重复结构单位为主链(骨架)的阴离子多聚物。在多数情况下，磷壁酸分子中的磷酸多元醇是磷酸甘油，或磷酸核糖醇，因此，根据主链组成不同可以将磷壁酸分为两大类: 磷酸甘油型磷壁酸 核糖醇型磷壁酸 ?幻灯片019.020)为革兰氏阳性细菌特有。有两种类型: a) 壁磷壁酸，与肽聚糖分子之间发生共价结合，可以用稀酸或稀碱提取，含量可达细胞壁重量的50%(细胞干重的10%)，含量多少与培养基成分密切相关; b) 膜磷壁酸(即脂磷壁酸)，有甘油磷酸链分子与细胞膜上的磷脂进行共价结合后形成的，其含量与培养条件关系不大，可以用45%热酚水提取，也可以用热水从脱脂的冻干细菌中提取。 磷壁酸的结构主要有甘油磷壁酸和核糖醇磷壁酸等物种类型，甘油磷壁酸，存在于Lactobacillus casei(干酪乳杆菌)等细菌中，核糖醇磷壁酸存在于Staphylococcus aureus和Bacillus(芽孢杆菌属)等细菌中。一般一种菌含有一种磷壁。 根据结合部位的不同分为: 壁磷壁酸:含量多，通过共价键与肽聚糖分子结合,并延伸到肽聚糖分子表面, 带有负电荷。 膜磷壁酸:与菌细胞原生质膜的脂类结合。 磷壁酸首先是在细胞壁中发现的，近年来还发现在细胞质膜也存在有磷壁酸，所以后者 又成为膜磷壁酸 磷壁酸的功能 ?协助肽聚糖加固细胞壁; rAt present, we have formed a "three-three" Park. …… Industrial Park, according to ... ... The instructions of comrade, focus on development needs in the next decade, based on the original, and then extended the 6 square kilometers. Of the Park, to further improve the roads, power supply, communications, water supply and drainage and sewage pipe network and other infrastructure, to achieve full coverage of infrastructure and interconnection with the facilities and raise capacity. Each park to determine 1 leading industries, in particular stone Materials, cans, gloves, through guided, force and other measures to promote the "road company" Park, industrial agglomeration. Currently, to focus on building better ... ... Industrial Park, ... ... Wood Park as the starting area of the industrial park, planners need to take out plan, start construction as soon as possible, undertake in a timely manner ... ... Transfer of the wood industry. This opportunity slip by, so the timing must be tight. Second is to optimize government service. Low efficiency of government services, departments do not coordinate the views of businesses large, poor business environment, it is ... ... Short Board, decide to change. We will continue to deepen reform of the administrative examination and approval system, good digestion, implement the Government canceled, adjustment and devolution of administrative examination and approval matters, strengthen the existing supervision in matters of administrative power, has made it clear to cancel, are not allowed to keep or disguised approval. To do list list of administrative powers and responsibilities ?增强细胞膜的稳定性; ?提高膜结合酶的能力(使细胞壁形成负电荷环境,以利于 吸附镁离子,维持酶活) ?构成噬菌体的吸附位点; ?形成表面抗原决定簇的主要成分。 ?保证革兰氏阳性致病菌(如A族链球菌)与其寄主间的粘连 磷壁酸的主要生理功能: a) 带负电荷，可与环境中Mg++等阳离子结合，提高这些离子的浓度，以保证细胞膜上一些合成酶维持高活性的需要; b) 保证革兰氏阳性致病菌(如A族链球菌)与其寄主间的粘连(主要为膜磷壁酸); c) 赋予革兰氏阳性菌以特异的表面抗原; d) 提供某些噬菌体以特异的吸附受体。 3,G,的细胞壁 细胞壁厚度 较薄10-15nm 细胞壁分层 分层: 外壁层 6-10nm 内壁层2-3nm 肽聚糖含量 只占组分的5-10% 肽聚糖层数 低，一般1-2层 肽聚糖交联度 较低 磷壁酸 有(在外膜层) 脂多糖 无 抗原决定因子 O-抗原 蛋白质 幻灯片023)以E. Coli为代表，肽聚糖含量 ~3nm。结构单体不足细胞壁的10%，一般由1~2层网状分子构成，在细胞壁上的厚度仅为与革兰氏阳性细菌基本相同，差别仅在于: a) 肽尾的第三个氨基酸为内消旋二氨基庚二酸(m-DAP); b) 没有特殊的肽桥，其前后两条肽聚糖链之间的联系仅由甲肽尾第四氨基酸——D-丙氨酸的羧基与乙肽尾第三氨基酸——m-二氨基庚二酸的氨基直接连接而成。 幻灯片023.022 示革兰氏阳性细菌与阴性细菌肽聚糖网的结构和致密度的差别。 外壁蛋白—为特异性载体,可将Vit B12这类较大分子送入细胞内。 基质蛋白——埋嵌在外壁层中,如孔蛋白,三聚体构成的疏水孔道贯穿外壁层,使小于800-900D的分子可通过,起分子筛作用。 脂蛋白—与肽聚糖层共价结合,并埋置在外壁层,使外壁层牢固的与内壁层连接。 革兰氏阴性细菌的外壁层中有许多镶嵌蛋白质，主要有: a) 基质蛋白(mattix protein)，如E. Coli中的孔蛋白(porin)就是一种研究较多的基质蛋白。孔蛋白是一种三聚体结构，每一个亚单位的分子量为36,000。由三聚体结构构成的充水孔道横跨外壁层，可通过分子量小于800~900的亲水性营养物质，例如糖类(尤其是双糖)、氨基酸、二肽、三肽、青霉素和无机离子等。它使外壁层具有分子筛的功能; b) 外壁蛋白(outer membrane protein)，是一种特异性的运送蛋白或受体，可把较大的分子如维生素B12、麦芽寡糖、核酸降解物以及铁离子螯合剂——铁色素(ferrichrome)或肠螯合素(enterochelin)等送入细胞内; c) 脂蛋白(lipoprotein)，种类很多，主要是分子量为7200的脂蛋白，其作用是使细胞壁的外壁层牢固地连接在由肽聚糖组成的内壁层上。 rAt present, we have formed a "three-three" Park. …… Industrial Park, according to ... ... The instructions of comrade, focus on development needs in the next decade, based on the original, and then extended the 6 square kilometers. Of the Park, to further improve the roads, power supply, communications, water supply and drainage and sewage pipe network and other infrastructure, to achieve full coverage of infrastructure and interconnection with the facilities and raise capacity. Each park to determine 1 leading industries, in particular stone Materials, cans, gloves, through guided, force and other measures to promote the "road company" Park, industrial agglomeration. Currently, to focus on building better ... ... Industrial Park, ... ... Wood Park as the starting area of the industrial park, planners need to take out plan, start construction as soon as possible, undertake in a timely manner ... ... Transfer of the wood industry. This opportunity slip by, so the timing must be tight. Second is to optimize government service. Low efficiency of government services, departments do not coordinate the views of businesses large, poor business environment, it is ... ... Short Board, decide to change. We will continue to deepen reform of the administrative examination and approval system, good digestion, implement the Government canceled, adjustment and devolution of administrative examination and approval matters, strengthen the existing supervision in matters of administrative power, has made it clear to cancel, are not allowed to keep or disguised approval. To do list list of administrative powers and responsibilities 脂多糖(LPS,lipopolysaccharide): 脂质A:为一种糖磷脂，由N-乙酰匍糖胺双糖、磷酸与多种长链脂肪酸组成，它是细菌内毒素的主要成分。 核心多糖:由2-酮-3-脱氧辛糖酸(KDO)、L-甘油-D-甘露庚糖、半乳糖及匍糖胺这样一组糖类组成。它一边通过KDO残基连接在脂类A上，另一边通过葡萄糖残基与O-侧链相连。 O-侧链(特异性多糖):是由多糖组成的重复单位，结构复杂，位于菌体的外表面，又称菌体抗原。由于各种革兰氏阴性菌多糖链的种类、排列顺序和空间构型都不同，造成革兰氏阴性菌的O-抗原有不同的特异性。 LPS分子一般都是由三部分(区段)组成 G-菌的脂多糖成分具有毒性，由于它细菌表面紧密结合，只有在菌体裂解时才被释放出来，故称为内毒素(endotoxin) 。 ?e. 脂多糖(LPS，lipopolysaccharide)的结构 脂多糖是阴性菌细胞壁的特有成分，也是外膜的主要和重要成分。 (幻灯片024.025)脂多糖是位于革兰氏阴性细菌细胞壁最外层的一层较厚(8~10nm)的类脂多糖类物质。它由类脂A、核心多糖O-特异侧链三部分组成。 ?———革兰氏阴性菌的脂多糖成分具有毒性，由于它细菌表面紧密结合，只有在菌体裂解时才被释放出来，故称为内毒素(endotoxin) 。 ————脂多糖主要由脂类A、核心多糖、和特异性多糖组成; ————脂类A是脂多糖的毒性部分。长杆菌科有共同的脂类A，其主要成份为ß—1、6D-葡萄糖胺双糖;其它革兰氏阴性菌的脂类A与此不完全相同，毒性也不同。(不同细菌的类脂A结构有所不同，大约有7~8种，它是革兰氏阴性细菌内毒素的毒性中心。) ————特异性多糖是由多糖组成的重复单位，结构复杂，突出表现在菌体表面，又称菌体抗原，或O抗原。由于各种革兰氏阴性菌多糖链排列的顺序和空间构型都不同，造成革兰氏阴性菌的O抗原有不同的特异性。沙门氏菌属的细菌根据抗原的不同，被分为2200余种。(在Salmonella中脂多糖分子中的O-特异侧链可用灵敏的血清学方法加以鉴定。这在传染病的诊断中有重要的意义，例如由此可对某传染病的传染源进行地理定位。) ?在LPS的核心多糖区和O-特异侧链区中有三种独特的糖:2-酮-3-脱氧辛糖酸(KDO)、L-甘油-D-甘露庚糖(Hep)和阿比可糖(Abq，即3，6-二脱氧-D-半乳糖)。 ?脂质A:为一种糖磷脂，由N-乙酰匍糖胺双糖、磷酸与多种长链脂肪酸组成，它是细菌内毒素的主要成分。各种革兰氏阴性菌的脂类A的结构与成分极为相似，无种属特异性。 核心多糖:由2-酮-3-脱氧辛糖酸(KDO)、L-甘油-D-甘露庚糖、半乳糖及匍糖胺这样一组糖类组成。它一边通过KDO残基连接在脂类A上，另一边通过葡萄糖残基与O-侧链相连。关系密切的菌种其核心多糖组分相同或极相似，故有属特异性。 O-侧链:位于LPS层的最外面，由重复的 寡糖单位或其它糖组成。糖的种类、顺序和空间构型是菌株特异的，这就形成了O-抗原特异性的结构基础。 LPS层的主要功能 ?构成某些革兰氏阴性细菌致病物质—内毒素的物质基础; ?起细菌自我保护作用，它可以阻止溶菌酶、抗生素和染料等侵入菌体，也可以阻止周质空间中的酶外漏; ?作为重要的抗原因子决定了革兰氏阴性菌抗原的多样性; ?是许多噬菌体吸附的受体。 LPS层的主要功能为: ? 构成革兰氏阴性细菌致病物质—内毒素的物质基础; rAt present, we have formed a "three-three" Park. …… Industrial Park, according to ... ... The instructions of comrade, focus on development needs in the next decade, based on the original, and then extended the 6 square kilometers. Of the Park, to further improve the roads, power supply, communications, water supply and drainage and sewage pipe network and other infrastructure, to achieve full coverage of infrastructure and interconnection with the facilities and raise capacity. Each park to determine 1 leading industries, in particular stone Materials, cans, gloves, through guided, force and other measures to promote the "road company" Park, industrial agglomeration. Currently, to focus on building better ... ... Industrial Park, ... ... Wood Park as the starting area of the industrial park, planners need to take out plan, start construction as soon as possible, undertake in a timely manner ... ... Transfer of the wood industry. This opportunity slip by, so the timing must be tight. Second is to optimize government service. Low efficiency of government services, departments do not coordinate the views of businesses large, poor business environment, it is ... ... Short Board, decide to change. We will continue to deepen reform of the administrative examination and approval system, good digestion, implement the Government canceled, adjustment and devolution of administrative examination and approval matters, strengthen the existing supervision in matters of administrative power, has made it clear to cancel, are not allowed to keep or disguised approval. To do list list of administrative powers and responsibilities ? 与磷壁酸相似，吸附Mg++、Ca++等阳离子而提高细胞壁的稳定性;(要维持脂多糖结构的稳定性需要足量的Ca++存在。如果用螯合剂去除Ca++，LPS就解体。这时革兰氏阴性细菌的内壁层肽聚糖就暴露出来，因此就可被溶菌酶水解)。 ? 作为重要的抗原因子决定了革兰氏阴性细菌抗原表位的多样性( 由于LPS结构的变化，决定了革兰氏阴性细菌性别表面决定簇的多样性，例如，据统计(1983)，国际上已报道过的根据LPS的结构特性而鉴定过的Salmonilla(沙门氏菌属)的表面抗原类型多达2107个); ? 是许多噬菌体在细胞表面的吸附受体。 ?起保护作用，它可以阻止溶菌酶、抗生素和染料等侵入细菌。 占细胞壁干重的% 成分 革兰氏阳性细菌 革兰氏阴性细菌 肽聚糖 含量很高(30~95) 含量很低(5~20) 磷壁酸 含量较高(<50) 无 类脂质 一般无(<2) 含量较高(~20) 蛋白质 无 含量较高 ,4,革兰氏阳性细菌与革兰氏阴性细菌细胞壁成分比较 ,5,细胞壁的功能: 1、决定了革兰氏染色的性质; 2、决定细菌的基本形态; 3、决定细胞的抗膨压(保护细胞免受渗透压变化的破坏) 4、决定对溶菌酶的敏感性; 5、决定了对青霉素的抗性; 6、为鞭毛运动提供支点; 7、决定细胞的抗原性; 8、决定细菌的毒性(致病性) 细胞壁的功能: a) 固定细胞外形; b) 协助鞭毛运动; c) 保护细胞免受外力的损伤(例如革兰氏细菌可抵御15~25个大气压的渗透压，革兰氏阴性细菌为5~10个大气压); d) 为正常细胞分裂所必需; e) 阻拦有害物质进入细胞(如革兰氏阴性细菌细胞壁可阻拦分子量超过800的抗生素透入); f) 与细菌的抗原性、致病性(如内毒素)和对噬菌体的敏感性密切相关 G，菌:细胞壁厚，肽聚糖网状分子形成一种透性障，当乙醇脱色时，肽聚糖脱水而孔障缩rAt present, we have formed a "three-three" Park. …… Industrial Park, according to ... ... The instructions of comrade, focus on development needs in the next decade, based on the original, and then extended the 6 square kilometers. Of the Park, to further improve the roads, power supply, communications, water supply and drainage and sewage pipe network and other infrastructure, to achieve full coverage of infrastructure and interconnection with the facilities and raise capacity. Each park to determine 1 leading industries, in particular stone Materials, cans, gloves, through guided, force and other measures to promote the "road company" Park, industrial agglomeration. Currently, to focus on building better ... ... Industrial Park, ... ... Wood Park as the starting area of the industrial park, planners need to take out plan, start construction as soon as possible, undertake in a timely manner ... ... Transfer of the wood industry. This opportunity slip by, so the timing must be tight. Second is to optimize government service. Low efficiency of government services, departments do not coordinate the views of businesses large, poor business environment, it is ... ... Short Board, decide to change. We will continue to deepen reform of the administrative examination and approval system, good digestion, implement the Government canceled, adjustment and devolution of administrative examination and approval matters, strengthen the existing supervision in matters of administrative power, has made it clear to cancel, are not allowed to keep or disguised approval. To do list list of administrative powers and responsibilities 小，故保留结晶紫-碘复合物在细胞膜上。呈紫色。 Gˉ菌:肽聚糖层薄，交联松散，乙醇脱色不能使其结构收缩，其脂含量高,乙醇将脂溶解，缝隙加大，结晶紫-碘复合物溶出细胞壁，沙黄复染后呈红色。 革兰氏染色原理: 第一步:结晶紫使菌体着上紫色 第二步:碘和结晶紫形成脂溶性大分子复合物，分子大，能被细胞壁阻留在细胞内。 第三步:酒精脱色，细胞壁成分和构造不同，出现不同的反应。 第四步:沙黄复染，增加脱色菌与背景的反差并区别于未脱色菌。 革兰氏染色机制:目前一般认为，革兰氏染色是基于细菌细胞壁特殊化学组分基础上的一种物理原因。通过初染和媒染操作后，在细菌细胞的膜或原生质体上染上了不溶于水的结晶紫与碘的大分子复合物。革兰氏阳性细菌由于细胞壁较厚、肽聚糖含量较高且分子交联度紧密，在乙醇洗脱时，肽聚糖网孔会因脱水而明显收缩，在加上它基本不含类脂，故乙醇处理不能在壁上溶出缝隙，因此结晶紫与碘的复合物仍牢牢阻留在其细胞壁内使其呈现紫色。反之，革兰氏阴性细菌因其壁薄、肽聚糖含量低和交联度松散，故遇乙醇后肽聚糖网孔不易收缩，加上它的类脂含量高，所以当乙醇把只类溶解后，在细胞壁上就会出现较大的缝隙，这样，结晶紫与碘的复合物就极易被溶出细胞壁，因此，通过乙醇脱色后，细胞又呈无色，这时再经沙黄等红色染料复染时即呈现红色。 溶菌酶对细胞壁的作用 ?可切断NAM和NAG之间的 —1，4糖苷键，引起细菌裂解。 ?对Gˉ菌，在EDTA存在下，受溶菌酶作用。 ?溶菌酶处理后的菌细胞应保存在弱高渗(0.1 ~0.2M)蔗糖液中。 ???肽聚糖是细胞壁主要成份，凡能破坏肽聚糖结构、或抑制其合成的物质都能使细胞壁损伤，甚至杀死细菌。———溶菌酶、青霉素】 溶菌酶(lysozyme):可切断NAM的G1和NAG的C4之间 —1，4的糖苷键，破坏肽聚糖支架，引起细菌裂解。(所以又称乙酰胞壁质酶。 ) 对Gˉ菌，在EDTA存在下，受溶菌酶作用。 溶菌酶处理后的菌细胞应保存在弱高渗(0.1 ~0.2M)蔗糖液中。 青霉素对细菌细胞壁的作用 Penicillium与转肽酶结合，而使该酶失活，抑制了侧链末端的丙氨酸与五肽桥的连接，破坏了细菌细胞壁的完整性(即抑制肽聚糖的合成)，因此， Penicillium仅对正在生长着的细菌，且主要是对G+菌有效。 青霉素对细菌细胞壁的作用点不同于溶菌酶，因此对细菌细胞的影响亦不尽相同。 rAt present, we have formed a "three-three" Park. …… Industrial Park, according to ... ... The instructions of comrade, focus on development needs in the next decade, based on the original, and then extended the 6 square kilometers. Of the Park, to further improve the roads, power supply, communications, water supply and drainage and sewage pipe network and other infrastructure, to achieve full coverage of infrastructure and interconnection with the facilities and raise capacity. Each park to determine 1 leading industries, in particular stone Materials, cans, gloves, through guided, force and other measures to promote the "road company" Park, industrial agglomeration. Currently, to focus on building better ... ... Industrial Park, ... ... Wood Park as the starting area of the industrial park, planners need to take out plan, start construction as soon as possible, undertake in a timely manner ... ... Transfer of the wood industry. This opportunity slip by, so the timing must be tight. Second is to optimize government service. Low efficiency of government services, departments do not coordinate the views of businesses large, poor business environment, it is ... ... Short Board, decide to change. We will continue to deepen reform of the administrative examination and approval system, good digestion, implement the Government canceled, adjustment and devolution of administrative examination and approval matters, strengthen the existing supervision in matters of administrative power, has made it clear to cancel, are not allowed to keep or disguised approval. To do list list of administrative powers and responsibilities