基于流式细胞技术的铜绿微囊藻自动识别参数筛选方法研究

微囊藻的快速定量研究是水华预防与控制的重要研究内容,本研究基于浮游植物流式细胞仪,探讨了铜绿微囊藻特征指标体系建立的方法.研究发现FL Red Average为将藻细胞与培养体系中杂质有效区分的最重要的指标.通过与显微计数和蛋白核小球藻的重复试验验证了该指标的有效性.在此基础上,以蛋白核小球藻为干扰信号,探讨了铜绿微囊藻特征指标建立的方法.结果表明,红色荧光信号均值(FL Red Average)为铜绿微囊藻最重要的特征指标,能实现铜绿微囊藻与杂质信号和蛋白核小球藻的有效区分.为兼顾准确与效率,结合指标的生理意义与数学特征,建议FL Red Average、SWS Average与FL Orange Average为铜绿微囊藻特征指标,相应的取值范围为1.39 mv～17.72 mv、22.05 mv～781.15 mv和0.43 mv～ 1.84 mv.     

地钱浸提液对小球藻的生长抑制效应

研究地钱对小球藻生长的抑制效应,筛选出廉价、高效、低毒的抑藻剂,对比分析了地钱与研究较为广泛的大麦秸秆对小球藻生长抑制效果的差异.结果显示,在0.5g/L地钱浸提液中培养120h后小球藻生长的抑制率达到88.17%,而0.5g/L大麦秸秆浸提液的抑制率只有66.28%.可见,在相同浓度条件下地钱浸提液的抑藻效果优于大麦秸秆浸提液;高浓度的25g/L地钱浸提液降低了小球藻的光合活性,而低浓度的1g/L浸提液对小球藻光合活性的影响不显著;通过对比乙醇和去离子水浸提液对小球藻抑制效果,说明对小球藻的生长起抑制作用的是地钱浸提液中的有机化感组分;地钱浸提液的抑藻效果与杨梅素、芹菜素和木犀草素这3种单一黄酮类化感物质相似.     

光合微生物燃料电池处理餐厨沼液的性能研究

采用小球藻作为双室光合藻微生物燃料电池（PAMFC）的阴极以提供电子受体,实现污水处理和能量回收的双重目的.研究生物阴极接种方式和光照条件对生物产电性能和餐厨沼液废水处理效果的影响,并通过循环伏安法（CV）研究PAMFC电极极化和产电机制.结果表明：微藻生物膜阴极PAMFC污染物去除和产电性能表现优于对照组,COD,TN和TP去除率最高可达82.4%,54.5%和82.3%,开路电压和最大功率密度分别达603.0mV和41.5mW/m².污染物去除主要在阳极发生,但阴极能够还原去除来自阳极的铵根离子,且阴极反应产生氧气作为阳极的电子受体,增大系统电流,提高了阳极处理效率.持续光照下,PAMFC产电性能和污染物去除率略高于间歇光照,但是间歇光照可以避免阳极基质不足时阴极光饱和和氧饱和情况,更符合连续运行要求.PAMFC阴极的CV曲线显示,具有微藻阴极的实验组输出电压更大,还原峰更高,功率密度更强,但需注意长期运行时微藻生物膜增厚影响氧传质效率的问题.     

Assessment of different carbon and salinity level on growth kinetics,lipid, and starch composition of Chlorella vulgaris SAG 211-12

ABSTRACT

The quality of microalgal biofuel depends on the fatty acid (FA) distribution. A high ratio of saturated fatty acids (SFAs) favors better biofuel characteristics. Palmitic acid (C16:0) and stearic acid (C18:0) are essential FAs for required biodiesel quality. In this study, combined effects of growth medium concentrations of NaCl, glucose and glycerol on cell composition and FA profile of the Chlorella vulgaris SAG 211–12 were investigated. A central composite design (CCD) based design of experiments (DoE) was used for experimental setup. According to experimental results, the maximum mass fraction for palmitic acid (C16:0), 40.67% of total fatty acids, was obtained in the medium supplemented with 0.9% (w/v) NaCl, 0.3% (w/v) glucose, and 0.3% (w/v) glycerol, whereas stearic acid (C18:0) percentage reached the highest value of 22.16% of total fatty acids in the presence of 2.5% NaCl, 0.6% glucose, and 0.6% glycerol. According to the same set of designed experiments, best starch content was found as 22.08% of dry cell weight in a medium containing 2.0% NaCl, 0.3% glucose, and 0.3% glycerol. C16:0 mass fraction as a function of three medium ingredient concentrations was modeled using a Kriging model. Optimum concentrations of NaCl, glucose and glycerol to reach maximum C16:0 fraction were predicted as 0.5, 1, and 1%, respectively.     

Distribution of14C-TNT and derivatives in different biochemical compartments ofPhaseolus vulgaris

¹⁴C-TNT was used to quantify the uptake rate and metabolic turnover of TNT inPhaseolus vulgaris. Seventeen plants were analysed by a special cell fractionation method with polar and nonpolar solvents and enzymes. We obtained three cytoplasmic fractions and five cell wall derived fractions. The recovery rate was 72% as measured by liquid scintillation counting.¹⁴C partitioned almost in equal amounts with approximately 50% in the cytoplasm and in the cell wall. The majority of the TNT-metabolites are present in the cytoplasm as was shown by GC/ ECD and thin layer chromatography. The¹⁴C in the cell wall is bound probably resulting in long-term immobilisation of these metabolites. We conclude that plants may also be a model for nitroaromatic turnover and immobilisation in soil components.     

Effect of the water-soluble fraction of diesel exhaust particles on the development and protein patterns of pollen grains in bean plants (Phaseolus vulgaris L.)

Excessive air pollution may adversely affect plant growth and development. The overall objective of this research was to elucidate some microscopic effects of diesel exhaust particles (DEP) on the formation, development, and structure of pollen grains and its proteins in Phaseolus vulgaris L. Bean plants were grown in experimental pots and treated with different concentrations of the water-soluble fraction of DEP. Flowers and young buds were removed, fixed in FAA₇₀ (formalin?:?acetic acid?:?ethanol, 2?:?1?:?17), and subjected to developmental studies. Our results show that DEP cause some abnormalities during pollen development. Pollen grains in normal plants are spherical in equatorial view and triangular in polar view; in DEP-treated plants, they were changed into irregular shapes in equatorial view and asteroidal in polar view. Delay in degeneration of the tapetum layer of the anther, and formation of giant, irregular, and non-fertile pollen grains are other results of DEP treatment. Gel electrophoretic studies revealed that a new protein with a molecular mass of 80?kD was formed in the DEP-treated group. Some pollen proteins may act as allergens, considering the fact that pollen allergy frequency is increased in polluted areas; the possibility arises that DEP could be an effective agent entail formation of detoxifying proteins which, on the other hand, can also act as allergens.     

小球藻引发水中环丙沙星的光降解效能研究

研究了小球藻引发水中环丙沙星的光降解、相同条件下藻液光致产生的自由基以及两者之间的关系.结果表明:环丙沙星的光降解率和自由基的产量随着藻浓度和藻破碎时间的增加而增大,藻液破碎时间大于20min时,环丙沙星降解率和自由基产量的增幅均减缓;小球藻超声功率为100W时,环丙沙星光降解率可达93.4%,此时自由基的产量也最大为313.4μmol/L,再增加破碎功率对两者均产生抑制作用.不管小球藻液的条件如何变化,其光致产生的自由基量和引发环丙沙星的光降解量均存在较好的线性相关性.     

纳米氧化镍对3种绿藻的毒性效应

通过配制不同浓度(0,60,120,180,240,300mg/L)纳米氧化镍(nNiO)悬浊液,对四尾栅藻(Scenedesmus quadricauda)、普通小球藻(Chlorella vulgaris)和羊角月牙藻(Selenastrum capricornutum)进行连续胁迫10d的毒性试验,测定nNiO对3种绿藻生长状况、叶绿素a、蛋白质、脂质过氧化物丙二醛(MDA)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)的影响.结果表明,nNiO胁迫对四尾栅藻、普通小球藻和羊角月牙藻的生长均有一定抑制作用,在同一时间段内,总体呈明显剂量效应;nNiO低浓度(60~120mg/L)胁迫对供试藻的影响表现为“抑制—促进—抑制”,在一定时间内对供试藻有促进生长的作用;nNiO胁迫对四尾栅藻、普通小球藻和羊角月牙藻的毒性效应表现为叶绿素a和蛋白质含量减少,MDA含量升高,抗氧化活性降低;羊角月牙藻对nNiO的耐受性较强,四尾栅藻和普通小球藻较敏感.     

镉胁迫对菜豆幼苗基因组DNA多态性的影响

采用随机扩增多态性DNA (RAPD)等技术,检测不同浓度镉(Cd)胁迫对菜豆幼苗叶片DNA损伤及相关生理特性的影响.结果表明,随着Cd处理浓度(0,20,40,80mg/L)的增加,菜豆幼苗中的Cd含量及叶片中丙二醛(MDA)含量升高;叶片中可溶性蛋白、脯氨酸、还原型谷胱甘肽在低浓度(20mg/L)Cd处理下含量增加,中、高浓度(40,80mg/L)Cd处理下减少.选取8条寡核苷酸引物(10bp),利用RAPD随机扩增技术,对菜豆幼苗叶片细胞基因组DNA进行扩增,8条引物均产生特异性谱带.正常叶片基因组DNA的RAPD图谱得到46条谱带.与正常组相比,Cd处理下利用不同引物扩增得到的RAPD图谱发生改变,呈现不同程度的谱带强度增强或减弱、谱带缺失或新增,与对照的RAPD图谱存在明显差异.Cd胁迫下基因组模板稳定性下降,并随Cd处理浓度的增加,稳定性下降幅度增大.利用RAPD技术获得的DNA多态性变化,可指示镉毒害生物遗传效应,并为镉污染地区蔬菜品种的选育及镉毒性的评价提供依据.     

不同pH条件下Cr6+对3种藻的毒性效应(The Toxicological Effects of Cr6+ on Chlorella Vulgaris, Scenedesmus Obliquus and Microcystis Aeruginosa at Different pH Values)

目前我国水质量生态基准的研究较为零星、分散.研究了不同pH条件下Cr6+对3种藻的毒性效应,以期为我国水生态基准的科学制定以及基准的相关研究工作提供参考.选取小球藻、斜生栅藻和铜绿微囊藻3种典型的藻种,在pH为7.0,8.0和9.0三个条件下,依据OECD-201藻类生长抑制实验指南,以72h藻生物量为测试终点,计算3种藻的比生长率,以及Cr6+对3种藻产生毒性效应的NOEC、LOEC、EC10和EC20值.结果表明,在本实验条件下,在不同pH条件下藻种生长不同,小球藻的最适pH值为7.0,斜生栅藻和铜绿微囊藻的最适pH值为9.0;在不同pH条件下,Cr6+对小球藻、斜生栅藻和铜绿微囊藻的毒性作用不同,Cr6+对小球藻在pH=7.0时毒性最小,对斜生栅藻和铜绿微囊藻在pH=9.0时的毒性最小.在藻最适生长的pH条件下,Cr6+的毒性可以达到最小程度;铜绿微囊藻对Cr6+比斜生栅藻和小球藻更加敏感.