微藻叶绿素荧光值与传统生长指标的关联性研究

利用TD-700型叶绿素荧光仪测定了6种不同海洋和淡水微藻,即锥状斯氏藻(Scrippsiella trochoidea)、球形棕囊藻(Phaeocystis globosa)、三角褐指藻(Phaeodactylum tricornutum)、眼点拟微绿球藻(Nannochloropsis oculata)、四列藻(Tetraselmis tetrethele)和雨生红球藻(Haematococcus pluvialis)的叶绿素荧光值,同时采用经典方法同步测定其细胞密度和叶绿素a含量。统计分析结果显示,微藻细胞密度、叶绿素a含量、叶绿素荧光值三者之间具有显著或极显著的正相关关系。因此,利用叶绿素荧光仪测定微藻生物量的方法是切实可行的,具有快捷方便、灵敏度高的优点。     

DMF提取微藻叶绿素a方法的改进

叶绿素ａ是估算藻类生物量的重要指标。叶绿素测定的关键环节在于将叶绿素从细胞中有效的提取出来。提取测定微藻叶绿素,传统采用的方法是将藻体浸泡于９０％丙酮中,在低温下过夜浸提。该方法不但耗时较长,且对于小球藻等细胞壁较厚的细胞很难将藻体中的叶绿素提取干净。Ｍｏｒａｎ ａｎｄＰｏｒａｈ［１］等报道用Ｎ,Ｎ－二甲基甲酚胺（ＤＭＦ）提取测定完整植物细胞的叶绿素可取得良好的效果。叶绿素的ＤＭＦ萃取液与丙酮萃取液光学性质极相似,可采用同样的测定条件进行分析［２］。于志刚等［３］的研究表明,丙酮提取液的叶绿素浓…     

黄甜竹笋用林的生物量,叶面积指数和叶绿素含量

簧甜竹笋用林生物量高达３０３７５ｋｇ／ｈａ,地上和地下部分的比值变幅在１．２￣１．５之间;杆的生物量最大,约为枝和叶的两倍;各器官含水量随年龄增加而减少;叶面积指数与其胸径、竹高、枝下高、冠幅相关,与植株年龄呈现抛物线关系;叶绿素含量除１年生外,随年龄增加而减少,且与叶片接受光照的程度有关,即接受光照越充分,叶绿素含量越高,但由于这些叶片生长较旺盛,衰老亦快,其叶绿素含量最终亦下降。     

黄甜竹笋用林的生物量、叶面积指数和叶绿素含量

黄甜竹笋用林生物量高达30375 kg/ha,地上和地下部分的比值变幅在1.2~1.5之间;杆的生物量最大,约为枝和叶的两倍;各器官含水量随年龄增加而减少;叶面积指数与其胸径、竹高、枝下高、冠幅相关,与植株年龄呈现抛物线关系;叶绿素含量除1年生外,随年龄增加而减少,且与叶片接受光照的程度有关,即接受光照越充分,叶绿素含量越高,但由于这些叶片生长较旺盛,衰老亦快,其叶绿素含量最终亦下降。     

荧光法测定蛇毒中磷脂酶的活性

利用二醋酸荧光素(FDA)可被磷脂酶水解,而本过程受卵磷脂抑制这一原理.对蛇毒及其它样品中的磷脂酶活性进行测量.初步探讨了该法的实验条件及其机理.研究结果表明,这个新方法可以简便、特异地测量出样品中的磷脂酶活性.我们利用该法测定了广东眼镜蛇粗毒及分离样、浙江蝮蛇粗毒,得到了和前人工作相近的结论;而在牛血清白蛋白中可检出磷脂酶活性,植物血凝素以及伴刀豆球蛋白中则检测不出磷脂酶活性.     

荧光法测定羽毛中的色氨酸含量

本文探讨了羽毛中色氨酸的荧光分析方法,将２～５ｍｇ的羽毛样品置于聚四氟乙烯管中,用１ｍｌ含０．５％可溶性淀粉的５ｍｏｌ／Ｌ　ＮａＯＨ为水解液,以纯氮为保护气体,在１１０℃水解２０小时,水解产物用６ｍｏｌ／ＬＨＣｌ中和,然后用Ｎａ２ＨＰＯ４－ＮａＯＨ的缓冲溶液（ｐＨ１１）稀释５倍,在激发波长２８０ｎｍ,发射波长３６２ｎｍ测定荧光强度及其浓度。经多次试验,结果较为满意,重现性较好,其相对标准偏差为０．６１％～３．００％。样品的回收率为９５．３％～１０２．１％。此法快速、简便,适用于各种羽毛的例行分析。     

荧光法测定发酵液中的苯丙氨酸含量

本文介绍荧光测定微生物发酵液中苯丙氨酸含量的方法。它的原理是苯丙氨酸和茆三酮在pH5.8的酸性二肽溶液中能形成荧光产物。所产生的荧光再被铜离子增强并稳定之后,即可用荧光分先光度计进行测定。测定的激发光波长为365mm,发射光波长为500nm。本文对荧光测定的条件进行了研究,结果表明荧光测定发酵液中苯丙氨酸的含量是一种专一性强,灵敏度高,操作简便的微量分析方法。     

土壤微生物生物量测定的简单方法

同时测定13种不同土壤精氨酸氨化速率、ATP含量、微生物生物量碳和葡萄糖诱导呼吸速率。精氨酸氨化速率0.1～17.1mg NH     

几种测定植物叶绿素含量的方法比较

植物叶绿素含量的测定大致可分为分光光度计法和活体叶绿素仪法两大类,目前还有人在研究反射型的活体叶绿素仪。本文就这些测定方法作些简要介绍和比较,以供读者参考。 1.分光光度计法由于所用提取叶绿素的溶剂不同,分光光度计法又有多种测定方法。 (1)丙酮法丙酮法是Mackinney(1941)首先     

利用叶绿素荧光监测微藻的生长及生理状态

衣藻与扁藻是生产生物柴油的优势藻种,监测其生长和生理状况是利用它们生产生物柴油的关键环节。本研究通过叶绿素荧光对这两种微藻的细胞密度进行监测并利用多激发波长调制叶绿素荧光仪(MultiColor-PAM)检测其在不同生长条件下的生理状况,获得本研究中两种藻的适宜的培养温度/光照强度:衣藻为28℃/80μmol/m~2·s~(-1),扁藻为28℃/100μmol/m2·s~(-1),利用叶绿素荧光可以便捷准确的监测微藻的生长及生理状态,为微藻培养及其代谢产物积累的研究提供切实可行的无损伤的检测方法。     

Quantification of algal biofilms colonising building materials: chlorophyll a measured by PAM-fluorometry as a biomass parameter

Abstract

The aim of this study was to quantify algal colonisation on anthropogenic surfaces (viz. building facades and roof tiles) using chlorophyll a (chl a) as a specific biomarker. Chl a was estimated as the initial fluorescence F₀ of ‘dark adapted’ algae using a pulse-modulated fluorometer (PAM-2000). Four isolates of aeroterrestrial green algae and one aquatic isolate were included in this study. The chl a concentration and F₀ showed an exponential relationship in the tested range between 0 and 400 mg chl a m^?2. The relationship was linear at chl a concentrations <20 mg m^?2. Exponential and linear models are presented for the single isolates with large coefficients of determination (exponential: r² > 0.94, linear: r² > 0.92). The specific power of this fluorometric method is the detection of initial algal colonisation on surfaces in thin or young biofilms down to 3.5 mg chl a m^?2, which corresponds to an abundances of the investigated isolates between 0.2 and 1.5 million cells cm^?2.     

Determination of microphytobenthic biomass using pulse-amplitude modulated minimum fluorescence

Microphytobenthos are the major intertidal primary producers in many estuarine systems and assessment of their biomass is essential in ecological studies. Algal biomass can be assessed by the use of proxy measurements, e.g. chlorophyll a (Chl a), using a lengthy and destructive extraction procedure. Fluorescence is a non-destructive and in situ alternative, recently applied to microphytobenthos, using the minimum Fluorescence signal (Fo) as a measurement of Chl a. In this study, Fo after 15 min of dark adaptation (Fo ¹⁵) showed a significant positive correlation with Chl a (r?=?0.84, p?n?=?24). The relationship between Fo ¹⁵ and Chl a extracted from sediment samples of increasing sample depth (0.2?2?mm) became less significant as sediment depth increased. The strongest relationship between Fo ¹⁵ and Chl a, expressed as concentration (mg?m^?2) and content (mg?kg^?1), was found when all data were combined, but nearly comparable levels of association were found for in situ measurements using sediment cores up to 2.0?mm deep. Results suggested that full dark adaptation was not always achieved because a significant negative correlation was observed between Fv/Fm and ambient irradiance for seasonal data. In addition, Fo ¹⁵ showed a more significant correlation with Chl a than with Fm ¹⁵, suggesting some residual level of non-photochemical quenching after 15 min in the dark. Despite the incomplete dark adaptation, the highly significant relationships between Fo ¹⁵ and both Chl a concentration and content suggest that the use of Fo ¹⁵ is a suitable in situ proxy method of estimating algal biomass.     

不同降水及氮添加对浙江古田山4种树木幼苗光合生理生态特征与生物量的影响

氮沉降和降水变化的不确定是目前全球变化背景下亚热带地区倍受关注的热点生态学课题,因此,探究降水变化及氮添加对亚热带森林植物生理生态特征及生长的影响可以为探讨全球变化背景下中国亚热带森林动态变化机制及保护和管理提供实验依据.在野外自然条件下,设置了3a的降水与氮添加控制实验,研究降水变化与氮添加对亚热带树木幼苗秃瓣杜英(Elaeocarpus glabripetalus)、枫香(Liquidambar formosana)、木荷(Schima superba)、青冈(Cyclobalnopsis glauca)生理生态特征及生长的影响.降水处理有3个水平:自然降水(对照,CK),增加30％降水(+H)及减少30％降水(-H);氮素处理有两个水平:自然状态(对照)及添加NH4NO3 10g·m-2·a-1(+N).由于亚热带地区土壤pH值偏低,大多数植物生长可能会受到土壤有效磷的限制而非氮限制,所以探讨在亚热带地区氮添加是否会影响树木的光合生理生态特征及生长,同时讨论降水变化与氮素的交互作用对4种树木幼苗的光合特征及生长的影响.实验结果表明:降水与氮素对树木光合生理生态特征及生长是有一定影响的.10 g·m-2·a-1 NH4N03氮添加水平可以提高4种树木幼苗叶片叶绿素含量(P＜0.05)、光系统Ⅱ最大光化学效率(Fv/ Fm)(P＜0.01)、光化学性能指数(PIABS)(P＜0.01)以及净光合速率(P＜0.05),4种树木幼苗总生物量在氮添加后显著提高了33.06％ (P＜0.01),因此古田山亚热带常绿阔叶林氮添加可以提高植物的光合性能,促进植物生长;降水变化对树种生理生态特征及总生物量的影响相对氮添加的影响较小,但是在古田山亚热带地区干季,降水对净光合速率(P＜0.05)、气孔导度和蒸腾速率(P＜0.001)的影响均达到显著水平,同时发现气孔导度对降水的变化更加敏感;降水与氮素的交互作用对树木光合生理生态特征(除PIABS)及总生物量的影响均没有达到显著水平(P＞0.05);不同树种间生理指标的差异是由树种生物学特性差异造成,不同树种间总生物量的差异受到氮添加与降水的影响,并且达到极显著水平(P＜0.01).     

Recycling and reuse of spent microalgal biomass for sustainable biofuels

The use of microalgal biomass (MAB) for biofuel production has been recognized since long. Despite distinct advantages of algal biofuels, however, their sustainability and economic viability is still doubtful. Overall process cost and low energy recovery need to be significantly improved. The use of MAB, after extracting primary fuels in the form of hydrogen, methane, biodiesel and bioethanol, can be one promising route. This algal biomass, collectively termed as spent microalgal biomass (SMAB), contains even up to 70% of its initial energy level and also retains nutrients including proteins, carbohydrates, and lipids. Potential application routes include diet for animals and fish, the removal of heavy metals and dyes from wastewater, and the production of bioenergy (e.g., biofuels and electricity). Unlike whole algae biomass whose applications are relatively well documented, SMAB has been studied only to limited degree. Therefore, this work gives a brief overview of various ways of SMAB applications. An insight into current status, barriers and future prospects on SMAB research is provided. The feasibility of each application is evaluated on the basis of its energy recovery, economic viability, and future perspectives are provided.     

Influence of irradiance,dissolved oxygen concentration,and temperature on the growth of <Emphasis Type="Italic">Chlorella sorokiniana</Emphasis>

The growth response of Chlorella sorokiniana to certain irradiance, DO, and temperature demonstrated the possible causes of low productivity with this strain in outdoor cultures. The growth (biomass productivity) and chlorophyll fluorescence (F_v/F_m) were substantially reduced when the dissolved oxygen (above 200 % of air saturation) and temperature were elevated.     

A novel polyculture growth model of native microalgal communities to estimate biomass productivity for biofuel production

Native polyculture microalgae is a promising scheme to produce microalgal biomass as biofuel feedstock in an open raceway pond. However, predicting biomass productivity of native polycultures microalgae is incredibly complicated. Therefore, developing polyculture growth model to forecast biomass yield is indispensable for commercial-scale production. This research aims to develop a polyculture growth model for native microalgal communities in the Minamisoma algae plant and to estimate biomass and biocrude oil productivity in a semicontinuous open raceway pond. The model was built based on monoculture growth of polyculture species and it is later formulated using species growth, polyculture factor (k_value), initial concentration, light intensity, and temperature. In order to calculate species growth, a simplified Monod model was applied. In the simulation, 115 samples of the 2014–2015 field dataset were used for model training, and 70 samples of the 2017 field dataset were used for model validation. The model simulation on biomass concentration showed that the polyculture growth model with k_value had a root-mean-square error of 0.12, whereas model validation provided a better result with a root-mean-square error of 0.08. Biomass productivity forecast showed maximum productivity of 18.87 g/m²/d in June with an annual average of 13.59 g/m²/d. Biocrude oil yield forecast indicated that hydrothermal liquefaction process was more suitable with a maximum productivity of 0.59 g/m²/d compared with solvent extraction which was only 0.19 g/m²/d. With satisfactory root-mean-square errors less than 0.3, this polyculture growth model can be applied to forecast the productivity of native microalgae.     

NaCl胁迫对两种番茄气孔特征、气体交换参数和生物量的影响

为探讨番茄叶片气孔特征、气体交换参数和生物量对盐胁迫的响应机理,以赛棚和阿拉姆番茄为试材,通过向水培营养液中添加NaCl(0.1 mol·L^-1),在人工气候箱条件下进行为期90 d的NaCl盐胁迫处理.结果表明: NaCl胁迫导致赛棚番茄叶片的气孔密度、气孔宽度、气孔面积和气孔面积指数显著降低,降幅分别为32%、45%、25%、49%,但没有改变阿拉姆番茄叶片的气孔特征参数.同时,NaCl胁迫还导致赛棚和阿拉姆叶片气孔规则分布的空间尺度分别减少30%和43%,且赛棚品种的单个气孔最小邻域距离在盐胁迫下增加20%.另外,赛棚和阿拉姆叶片的净光合速率(P_n)、气孔导度(g_s)和蒸腾速率(T_r)在盐胁迫下均显著下降,通过气孔限制值分析发现,盐胁迫导致赛棚番茄叶片光合速率下降主要是由气孔限制因素引起的,而阿拉姆叶片则以非气孔限制因素为主导作用.盐胁迫还导致赛棚和阿拉姆番茄生物量显著降低,且地下生物量的下降幅度大于地上生物量.综合分析表明,阿拉姆的抗盐能力高于赛棚.     

絮凝微生物采收微藻的作用机制研究进展

微藻广泛分布于自然界,其易培养,生长快且应用价值高,普遍用于生物燃料、医学原料、优质食品源及畜牧养殖业等。近年来,通过对光生物反应器改造设计、高产藻株筛选、代谢通路基因改造等方法实现微藻产量的提高,而在微藻处理的下游过程的研究与创新不足,特别是微藻采收已经成为其产业发展的瓶颈。本文综述了絮凝法在微藻采收中的作用,重点讨论了絮凝微生物在微藻采收中的作用,并对絮凝微生物对微藻的絮凝机制进行广泛探讨,为絮凝微生物采收微藻提供理论依据。     

微藻光密度与细胞密度及生物质的关系

以四种常见微藻,小球藻(Chlorella sp.XQ-20044)、栅藻(Scenedesmus sp.SS-200716)、绿球藻(Chlorococcum sp.)和螺旋藻(Spirulina sp.CH-164)为实验材料,用梯度稀释法测定对数生长期不同浓度藻液的光密度(OD)、细胞密度和生物质干重(DW),在光自养分批培养模式下对4种微藻进行OD-波长(350—800 nm)扫描,同时测定细胞密度和生物质干重,分析藻液OD与细胞密度、生物质干重的关系。结果表明:在任何波长下,对数生长期的4种微藻细胞密度与OD值、生物质干重与OD值的变化都不成比例,波长不同其拟合曲线偏离直线的程度不同。但是,在435 nm处这种关系最接近直线,可以用直线方程近似描述(R20.98),其它波长处细胞密度-OD、干重-OD的关系都可以用二项式方程很好地描述(R20.99)。因此,光密度法适用于连续和半连续培养,可以用435 nm处测得的OD值计算细胞密度与干重。但是在分批培养模式下,4种微藻DW/OD比值随着培养时间均逐渐上升。小球藻DW/OD540为0.19—0.44 g/L,栅藻DW/OD540为0.36—0.53 g/L,绿球藻DW/OD540为0.48—0.75 g/L,螺旋藻DW/OD560为0.46—0.74 g/L,因此分批培养模式下采用测定藻液OD值反映细胞密度和生物质的方法不适用,只有直接测定细胞密度和生物质才是准确的。研究结果为正确使用分光光度法监测微藻生长提供依据。