Response of phytoplankton to nutrients addition in the upwelling regions of the Taiwan Strait

2006年6月在台湾海峡近岸上升流区通过表层水体营养盐添加的现场培养实验,研究该海区营养盐限制情况及其浮游植物水华产生的主要影响因素。对营养盐,叶绿素a浓度和浮游植物细胞丰度进行了测定,结果表明,实验中不存在明显的硅限制;氮磷营养盐均存在明显的限制,且氮限制情况更为严重。营养盐添加后,冰河拟星杆藻(Asterionellopsis glacialis)等硅藻迅速生长成为优势藻种,其对氮磷的利用机制有所不同。对氮营养盐采取吸收后迅速同化利用,相较于硝酸盐的补充,氨氮补充条件下优势硅藻更易迅速生长并迅速死亡;对磷营养盐的利用则由于体内磷库的存在,采用迅速吸收后贮存在体内慢慢消耗的利用机制。氮营养盐的补充是上升流期间浮游植物水华产生的主要因素。 【英文摘要】 In situ incubation experiments of nutrients addition to surface water from the upwelling region in the Taiwan Strait were conducted to investigate nutrient limitation of this area and the main factors that caused the phytoplankton bloom in June,2006.Variation of nutrients,Chl-a concentration and phytoplankton species density were analyzed.The results showed no clear limitation by silicon,however clear nitrogen and phosphate limitations were found,and nitrogen limitation was more serious than phosphate limit...国家自然科学重点基金资助项目(40331004)~

Physiological-ecological responses of phytoplankton to nitrogenous nutrients in the Taiwan Strait upwelling area

本论文结合现场调查、船基围隔实验、现场和实验室培养等实验手段，以台湾海峡南部海区上升流期间浮游植物优势种－冰河拟星杆藻（AsterionellopsisglacialisRound,1990）为模式种，运用酶学、生理学和蛋白质组学等方法和技术，从营养需求、氮营养盐吸收动力学、同化酶活性和酶动力学以及蛋白质组学等角度，研究了冰河拟星杆藻氮营养生理及其对营养盐变动的响应。结合现场数据，从分子水平上探讨了台湾海峡南部近岸上升流区浮游植物优势种水华形成机制及其对现场氮营养盐补充的响应机理。主要实验结果如下：1、在比较研究三种谷氨酰胺合成酶（GS）提取方法的基础上，优化了浮游植物GS的提取方法。结果表明...This study investigated the physiological response of phytoplankton to variations in nitrogenous nutrients in the upwelling area of the Southern Taiwan Strait using a field survey, ship-based mesocosm experiments, in situ culture experiments and laboratory-based experiments, The nitrogenous nutrient requirements, uptake kinetics, nitrogen-assimilation enzyme activities and kinetics, and proteomics...学位：理学博士院系专业：海洋与环境学院环境科学与工程系_环境科学学号：B20043400

渤海典型生态灾害的发展变化特征及演变趋势

渤海是中国的内海,受海岸带地区人为活动的影响,海域生态环境退化严重,其主要表现为海洋生态灾害频发。本文对渤海近年典型生态灾害,如赤潮、大型藻类及水母发生的时空分布特征进行了总结,结合水环境变化,对其演变趋势进行了评估,并提出了相应的防控应对建议

西方马克思主义视阈中的资本主义社会关系再生产及其层次

在马克思那里,资本主义社会关系再生产比物质条件本身的再生产更为重要,因而是资本主义研究与批判的核心问题。随着资本主义的时代发展与变迁,资本主义社会关系再生产所内含的潜在层面逐渐凸显,成为了西方马克思主义理论转向的焦点,其先后呈现出来的三大主题——意识形态、日常生活与空间,实际上也代表了资本主义社会关系再生产的三个重要层次。基于资本主义社会关系再生产这一理论视角,本文梳理了西方马克思主义对马克思资本研究思路的时代发展及其理论得失。国家社会科学基金青年项目“《资本论》及其手稿中的空间生产理论研究”[项目编号:14CZX001]的阶段性研究成

聆听时代声音,展现真理力量——十九大精神有机融入高校思政课的必要性及其路径

高校思政课事关思想政治工作全局,是重要的意识形态安全保障工程。对于思政课教师而言,将十九大精神融入思政课教学过程不仅必要,而且具有积极的现实意义。通过激活师生两大主体,构建积极有效的良性意识形态\"同意\"机制,是十九大精神有机融入思政课的前提。融入的有效路径在于,以十九大精神为导引,以专题教学为抓手,处理好专题教学与教材,与马克思主义理论整体性、系统性和方向性之间的关系,同时在专题教学中处理好政治性、学术性与时代性之间的关系,充分彰显马克思主义理论与共产主义理想信念的时代温度与热度。教育部示范马克思主义学院与优秀教学科研团队建设项目“思想政治理论课专题式教学设计与实践”(16JDSZK012);;福建省本科教学改革项目“‘全程育人、全方位育人’理念下的思政课专题化教学改革研究——以‘马克思主义基本原理概论’为例”(FBJG20170296)的阶段性研究成

Spatial distribution and correlation of environmental factors andchlorophyll a concentrations in the Bohai Sea during the summer of 2013

通过对2013年7月渤海海域26个站点温度、盐度、营养盐及叶绿素a(Chl a)浓度的空间分布特征及其相关性进行了分析,发现:受渤海水深和夏季陆源河流输入影响,近岸水域表现出明显的高温、低盐与高营养盐特征,且垂直变化特征不显著;在水深较深的辽东湾湾口和渤海海峡,海水呈现明显的层化现象,表层水温高于中底层,而表层盐度与营养盐浓度则低于中底层。营养盐结构分析表明,渤海夏季磷酸盐浓度存在显著的绝对与相对限制,而受河流输入影响,硅酸盐的相对限制得到显著缓解。表层Chl a浓度的高值区位于滦河及复州河河口附近海区,中层与底层的高值区则出现在滦河与黄河口附近。Chl a浓度与环境因子的相关性分析表明,盐度..

凝结芽胞杆菌利用非粮生物质合成乳酸的研究

乳酸被广泛应用于食品、医药、化妆、纺织和化工等领域，近年来生物可降解材料聚乳酸的生产，加大了工业乳酸的需求量。微生物发酵法是工业生产乳酸的主要方法，但原料成本及发酵工艺是制约生物合成乳酸规模化生产的主要因素。本研究以嗜热凝结芽胞杆菌（Bacillus coagulans）IPE22为出发菌株，以非粮生物质为原料，对开放式发酵生产乳酸的规律及机理进行研究。（1）针对淀粉质生物质，首先以可溶性淀粉做碳源研究B. coagulans IPE22开放式发酵合成乳酸的机制，发现IPE22菌株可以分泌淀粉酶（29.47 mU/mg）并合成乳酸，但乳酸生产强度较低（0.80 g/（L&middot;h））。进而，针对传统工艺中以淀粉为原料合成乳酸时存在的最适酶解温度与发酵温度不一致导致的操作繁琐问题，利用多种淀粉酶开展不同的酶解策略研究，发现添加中温&alpha;-淀粉酶和糖化酶的一步法同步液化糖化发酵（SLSF）工艺可以高效合成乳酸，淀粉转化率、乳酸得率和生产强度分别可达89.77%、0.99 g/g和1.72 g/（L&middot;h）。最后，以富含淀粉的非粮生物质（木薯粉和高粱粉）代替可溶性淀粉开展一步开放式发酵合成乳酸实验，发现乳酸发酵性能与可溶性淀粉为原料时无明显差异。同时，研究还发现在不添加外源酶以淀粉做碳源开放式发酵合成乳酸过程，偶尔会出现乳酸得率下降及副产物大量合成的异常现象，经分析发现该过程主要是污染了B. licheniformis和B. thermoamylovorans两种杂菌。为避免开放式发酵过程染菌的发生，对开放式发酵体系进行了系统的研究，进而开发了不同的污染防控策略。结果表明在开放式发酵初始额外添加葡萄糖或乳酸钠（10 g/L）可以分别减少45.15%和60.81%副产物的生成，而利用新分离的B. thermoamylovorans 48-3和B. coagulans IPE22进行混菌发酵不仅有效避免了杂菌污染（副产物减少95.90%），且与IPE22单菌发酵（0.81 g/g）相比乳酸得率（0.90 g/g）提高了11.11%。（2）虽然采用淀粉质非粮生物质可以一步法开放式发酵合成乳酸，但一些传统被认为是非粮作物的原料目前也被开发用作食品，因此寻求其它非淀粉质非粮生物质做碳源十分必要。木质纤维素原料近年来受到了全世界的广泛关注，但不同原料的水解液中己糖（hexose，如葡萄糖）与戊糖（pentose，包括木糖和阿拉伯糖等）的比例（H:P）差异很大（0.08~6.50），然而H:P的比例对乳酸生产的影响尚不清楚。因此，本文首先研究IPE22菌株利用60 g/L单糖（葡萄糖、木糖、阿拉伯糖）的发酵性能，发现葡萄糖倾向于促进乳酸合成，木糖有益于强化细胞的生长。进而，研究IPE22菌株利用不同H:P混合糖模拟液（60 g/L）的发酵性能，发现随着戊糖含量的降低，最大菌体浓度（OD620）随之减小（从12.50到7.61），生产强度相应下降（3.08到2.05 g/（L&middot;h）），但乳酸产量却始终保持在大约50 g/L。最后，以总糖含量为60 g/L的玉米芯水解液为底物进行发酵，发现其生产强度（2.97 g/（L&middot;h））高于单独以葡萄糖为碳源（2.34 g/（L&middot;h））的发酵过程。因此，不同来源的木质纤维素非粮生物质均可被用做原料生产乳酸, 是一种良好的潜在发酵底物。另外，酸预处理后的玉米芯水解液经氢氧化钠中和后含有大量硫酸钠（2%），对发酵菌株的生长有抑制作用。因此，本文研究将利用双极膜电渗析技术对中和后的玉米芯酸水解液进行脱盐，硫酸根和钠离子的去除率分别为79.07%-86.31%和84.63%-90.90%。利用双极膜电渗析技术脱盐后，回收所得酸溶液用于玉米芯的酸水解实现循环利用，经过四个循环后，共节省了37.02%的硫酸。所以，利用双极膜电渗析技术不仅可以有效去除木质纤维素水解液中的无机盐抑制物，还可以将此无机盐转化为酸碱并进行循环利用，从而减少整个过程中废弃物的产生和资源的浪费。综上所示，本论文针对淀粉质生物质做碳源时建立的一步法同步液化糖化开放式发酵生产乳酸工艺，和针对纤维素源生物质建立的开放式发酵及酸水解液综合利用工艺对开放式发酵合成乳酸具有重要意义。;Lactic acid (LA) was widely used in food, pharmaceutical, cosmetic, textile and chemical areas, and in recent years the production of biodegradable polylactic acid has increased the demand for industrial LA. Microbial fermentation was the main method for industrial LA production, but the cost of raw materials and fermentation process were the main factors that restricted the large-scale biosynthesis of LA. In this study, Bacillus coagulans IPE22 was used as the starting strain, and inedible biomass was used as raw material to study the law and mechanism of open LA fermentation.(1) For starchy biomass, the mechanism of LA fermentation by B. coagulans IPE22 was firstly studied using soluble starch as carbon source. It was found that IPE22 strain can secrete amylase (29.47 mU/mg) and synthesize LA though the productivity is low (0.80 g/(L&middot;h)). Furthermore, aiming at the cumbersome operation caused by the inconsistent temperature of enzymatic hydrolysis and fermentation in the conventional LA production process, various amylases were adopted to carry out fermentations with different enzymatic hydrolysis strategies. It was found that one step simultaneous liquefaction, saccharification and fermentation (SLSF) with the addition of mesothermal &alpha;-amylase and glucoamylase was the optimal mode with conversion rate, yield and productivity of 89.77%, 0.99 g/g and 1.72 g/(L&middot;h) respectively. Finally, inedible starchy biomass (cassava and sorghum flours) were used instead of soluble starch to carry out one-step open LA fermentation, and no significant difference was found.At the same time, abnormal phenomenon of decreased LA yield and increased by-products accumulation appeared occasionally during open LA fermentation from starch without the addition of exogenous enzyme, which was mainly caused by the contamination of B. thermoamylovorans and B. licheniformis. In order to avoid the microbial contamination during open fermentation, systematic research was carried out and different contamination prevention and control strategies were developed. The results showed that the addition of glucose or sodium lactate (10 g/L) at the initial of open fermentation reduced the accumulation of by-products by 45.15% and 60.81% respectively. However, the co-fermentation of newly isolated B. thermoamylovorans 48-3 with B. coagulans IPE22 was the most effective strategy, which not only reduced 95.90% by-products formation also increased the LA yield (0.90 g/g) by 11.11% (compared to single strain fermentation (0.81 g/g)).(2) Although starchy inedible biomass could be used to produce LA by one-step open fermentation, some of them traditionally considered inedible have been currently developed as food. Thus, seeking other non-starch inedible biomass was necessary. Lignocellulosic materials attracted widely attention in recent years, however the ratio of hexose (glucose) to pentose (xylose and arabinose) of different lignocellulosic hydrolysates (H:P) varied greatly (0.08~6.50), and their effects on LA production were unclear still. In this study, sugars (glucose, xylose and arabinose) of 60 g/L were utilized as carbon source separately, and results proved that glucose tended to promote LA production while xylose preferred to enhance cell growth. Then, fermentations of simulated sugar mixtures (60 g/L) with various H:P ratios were studied. With the increase of pentose content, maximal cell density (13.10 to 7.61) and LA productivity (3.08 to 2.05 g/(L&middot;h)) decreased, while similar LA concentrations (50 g/L) were obtained. At last, corn cob hydrolysate with 60 g/L sugars was used to produce LA, and its productivity (2.97 g/(L&middot;h)) was higher than that of single glucose utilization (2.34 g/(L&middot;h)). In all, lignocellulosic biomass derived from various sources could be applied to produce LA, and they were good alternatives of fermentation substrates.In addition, corncob acid hydrolysate neutralized by sodium hydroxide contained a large amount of sodium sulfate (2%), which inhibited the growth of B. coagulans. In this study, the hydrolysate was desalted by bipolar membrane electrodialysis (BMED), and the removal rates of sulfate and sodium ions were 79.07%-86.31% and 84.63%-90.90% respectively. The acid solution recovered from desalination by BMED was recycled through acid hydrolysis of corn cob, and a total of 37.02% sulfuric acid was saved after four recycles. Therefore, inorganic salt inhibitors were removed effectively by BMED technology, and the acid and alkali recovered from salt inhibitors were recycled meanwhile, which reduced pollution generation and resource waste in the whole process.In summary, the one step open SLSF process for starchy biomass and the open fermentation and acid hydrolysate integrated utilization process for lignocellulosic biomass were both established in this study, which was of great significance for open LA fermentation.</p