Screening and Characterization of H2-Production Strain Enterbacter sakazakii HP

能源危机与环境污染问题受到人们越来越多的关注，开发新的能源体系已成为世界各国的共识。氢由于其本身无色、无嗅、无毒且燃烧后仅生成水而被认为是理想的清洁能源。另外，氢的能量密度高，其热值为143MJ/kg，约为石油热值的3倍；它能以气态、液态或固态金属氢化物的形式储存，能满足储运及各种应用环境的不同要求。因而“氢经济”成为各国经济发展规划的重要组成部分。 本研究对高温环境的样品进行分离，通过初筛和复筛，选出一株产氢性能稳定且活性较高的菌株。通过对菌株的形态结构、生理生化特征及16SrRNA基因序列进行分析，鉴定该菌株为阪崎肠杆菌（Enterbactersakazakii）。分析了pH值、碳源、菌...As the economy develops, the energy source problem and the environmental issue are paid more and more attention. Developing new energy system has become basic. Many of the countries are concerning about the development of the new energy system. Hydrogen energy has been considered as one of the most ideal future energies as it is clean, pollution-free, high heat value and easily storage and transpo...学位：理学硕士院系专业：生命科学学院生物学系_微生物学学号：20042614

Isolation and Characterization of a H2 -producing Strain Enterbacter sakazakii HP

通讯作者 Tel 0592-2185731, E-mail： longmn@ xmu.edu.cn[中文文摘]在自然环境中分离到一株具有高产氢活性的微生物菌株,经细菌鉴定仪及16S rRNA基因序列分析,鉴定该菌株为Enterbacter sakazakii HP。分析了起始pH值、反应温度、碳源、起始糖浓度、起始氧浓度及菌体密度等因素对菌株产氢活性的影响。研究表明,该菌株发酵产氢较适合的条件为:以葡萄糖为产氢底物,起始pH值8.0,菌体密度OD600=0.7,反应温度35℃,糖浓度为0.1mol/L,氧浓度为0%的条件下,此时产氢菌株的最高产氢活性为5.34μmolH2/h.mgdw,氢的得率为1.94molH2/mol葡萄糖。[英文文摘]A H2 -producing bacterial strain was newly isolated and identified as Enterbacte sakazakii HP by 16S rDNA sequence analysis and detection by BBLCRYSTAL AUTOREADER.Various factors,including substrates and its concentration,initial pH,temperature and oxygen,on the hydrogen production of E.sakazakii HP have been studied extensively.Among several sugars,glucose was the favorite substrate for hydrogen production.The optimum condition for hydrogen production by Enterbacte sakazakii HP was achieved as:initial pH8.0,cell density OD600 =0.7,temperature 35℃,glucose concentration 0.1 mol/L,oxygen concentration 0%.Under batch fermentative hydrogen production conditions,the maximal hydrogen production activity and hydrogen yield were obtained as 5.34μmol H2 /h·mg dw and 1.94mol H2 /mol glucose,respectively.The research results suggest that Enterbacter sakazakii HP is an ideal candidater for biological hydrogen production.国家自然科学基金项目(No30470395);厦门市科技项目(No3502Z20041070);厦门大学新世纪优秀人才计划项目;福建省青年科技人才创新项目(No2005J003

Biohydrogen Production from Rice Straw by Simultaneous Saccharification and Fermentation Using Klebsiella oxytoca HP1

氢作为一种清洁的能源引起了人们的普遍重视.实验以产酸克雷伯氏菌(Klebsiella oxytoca)HP1为产氢菌株,以稻草粉为产氢底物,进行同步糖化发酵(Simultaneous Saccharification and Fermentation,SSF)产氢.对影响同步糖化发酵产氢的单因子进行试验,选取对氢产率影响较大的因子:温度、pH、纤维素酶用量等进行L9(34)正交试验.结果表明同步糖化发酵产氢的最佳条件为:温度40℃,pH6.5,纤维素酶用量为20FPAU/g稻草粉,摇床转速100r/min,发酵时间42h.在该条件下的最大氢产率为110.6mL/g稻草粉,稻草粉的氢转化率为22%.进行了10L放大发酵产氢试验,最大氢产率为122.3mL/g稻草粉,氢转化率为24.3%.与分步糖化发酵(Separate Hydrolysis and Fermentation,SHF)产氢相比,氢产率提高34.4%.研究表明,利用同步糖化发酵工艺可以提高生物制氢的产量和得率.Being regarded as a clean energy source,biological hydrogen attracts more and more attention.Hydrogen production from rice straw by simultaneous saccharification and fermentation (SSF) was studied using the Klebsiella oxytoca HP1 in this report.The experiments of batch ferment hydrogen production were carried out in 600 mL serum bottles.Single factor and orthogonal experiments showed that the optimal conditions for hydrogen production were:pH6.5,ferment temperature 40℃,cellulose dose 20 FPAU/g rice straw,revolution 100 r/min and ferment time 42 h.The maximum H2 production (110.6 mL/g rice straw) and H2 yield efficiency (22%) were obtained under the above conditions.The enlarge experiments were carried out in a 10 L bioreactor,a maximum H2 production of 122.3 mL/g rice straw and a H2 yield efficiency of 24.3% were achieved.The H2 production increased by 34.4% compared with the separate hydrolysis and fermentation hydrogen production.This research indicated a perfect application of SSF in biohydrogen production from cellulose material.国家自然科学基金项目(30470395);; 厦门市科技项目(3502Z20041070);; 厦门大学新世纪优秀人才计划项目(X07114)资

重离子诱变技术选育碱性蛋白酶高产菌株；The Selection for High-yield Alkaline Protease Producing Strain by Heavy-ion Irradiation

从采集的土壤样品中分离筛选出一株碱性蛋白酶产生菌G-41,经16S rRNA分子鉴定为芽孢杆菌属菌株。该菌株在发酵培养基中能产生较高产量的胞外碱性蛋白酶(1.7×104U/mL)。以G-41为出发菌株,对其进行重离子辐照诱变处理,获得突变株G-41-68,将该突变株再次经重离子诱变,从大量突变株中筛选出碱性蛋白酶高产菌株15Gy-54,其酶活力达到6.22×104U/mL。与出发菌株相比较,突变株G-41-68和15Gy-54的酶活力分别提高了1.58倍和2.65倍。对突变株15Gy-54的发酵条件进行了优化研究,结果表明,该菌株的碱性蛋白酶活力得到进一步提高,达到7.18×104U/mL,其最适发酵条件为:培养基(g/100mL)为胰蛋白胨1、酵母膏0.5、乳糖5、Na2HPO4·12H2O0.4、KH2PO40.03、Na2CO30.1、MgSO40.0481(4×10-3mol/L)、pH8.0,培养温度41℃,振荡培养时间42-48h。实验结果表明,重离子辐照诱变技术是一种非常有效的微生物诱变育种新技术

80 MeV/u C-12离子诱变选育PHB高产菌株；A strain of high PHB output by mutagenesis of 80 MeV/u C-12 ions

用80MeV/u12C6+离子对一株积累聚β-羟基丁酸酯(PHB)的芽孢杆菌(BacillusP-9)进行诱变选育,最终获得PHB高产株菌G15,其PHB产量达2.93g/L,与出发菌株相比较,PHB积累量提高了1.5倍。研究结果表明,本试验辐照最佳剂量为15Gy。重离子辐照诱变育种效果显著,具有广阔的发展应用前景

Electrochemical Studies of Spinel LiMn 2O 4 Rechargeable Lithium Battery

本文报导尖晶石型ＬｉＭｎ２Ｏ４化合物的制备方法，用循环伏安法和交流阻抗技术研究了Ｌｉ／有机电解液／ＬｉＭｎ２Ｏ４电池的电化学行为，用分形理论首次考察和进一步讨论电极材料的阻抗行为随锂离子嵌入或脱嵌电极时的变化The spinel Li intercalation compound LiMn 2O 4 was prepared and studied using ac impedance and cyclic voltammogram techniques. It was first discussed that the impedance behaviors of LiMn 2O 4 electrode varied as lithium ion was intercalated in or out the electrode with the help of fractal theory. The Li reversible behaviors in LiMn 2O 4 electrode were shown by the cyclic voltammogram results.作者联系地址：中国科学院长春应用化学研究所Author's Address: Changchun Inst. of Applied Chem., Chinses Academy of Sciences, Changchun 13001

艾比湖地区植被和土壤在南-北区段上的差异性分析/South-north differences of vegetations and soils in the Aibi Lake area[J]

从艾比湖两岸大致沿同一经度分别向南北山前地带,对39个样地进行野外调查和样品采集.通过研究植被结构和土壤性质的变化特征,探讨了植被-土壤在南北两断面上的差异.结果表明:两地植被存在群落中优势种群类型、数量、长势及其空间分布的差异,而多样性指数及植被盖度的统计学差异并不显著;土壤的粒度平均水平明显不同,而粒度的离散性及对正态的偏离度仅在表层差异显著;多种养分含量差异均显著;土壤表层、次表层含水量、含盐量(包括盐分主要离子含量)和pH的平均水平及变化程度,南北差异的显著性不一致,但整体上看,仍属于比较明显的范畴.这些差异是艾比湖南北地形、水文、气象、物源明显不同的结果,也是植被和土壤耦合作用的结果

艾比湖地区植被分布及物种多样性研究/Study on Vegetation Distribution and Species Diversity in the Ebinur Lake Basin[J]

应用重要值计算多样性指数、均匀度指数、优势度指数,对艾比湖流域植被分布及物种多样性进行分析。结果表明：①研究区域内可划分出10个群落,其中多枝柽柳群落（Form.Tamarix ramosissima）分布最为广泛。②湖岸植被表现出明显的带状分布特点,并且群落物种多样性随地势发生变化,地势高的地方,物种多样性较高,均匀度较好。③在南北断面内,影响植物生长的主要因素为土壤含盐量。随着土壤盐分的增加,物种种类趋向单一,群落结构趋向简单。相反物种多样性随着土壤盐分的减少而增大。④受风况和土壤含盐量的影响,南北断面植被组成差异较大,且在近湖岸范围内,南断面植物群落物种多样性和植物生长状态明显优于北断面