钝顶螺旋藻形态、生长及光合作用对不同波段太阳辐射的响应（英文）

为探讨中不同波段的光合有效辐射对钝顶螺旋藻(Arthrospira platensis)形态、生长及光合作用的影响,实验将钝顶螺旋藻D-0083藻液转入带塞的石英管中,石英管水平置于阳光下并在其上覆盖不同的截止型和带通型滤光片,以使藻丝接受不同波段的太阳辐射;并检测其生长、形态与光合活动的变化。结果发现:所有波段(320—500、395—700、510—700和610—700 nm)光合有效辐射下的藻丝均螺旋变紧且生物量增加。其中以包含少量紫外辐射A(Ultraviolet-A)的蓝光波段(320—500 nm)和红光波段(600—700 nm)对藻丝形态变化、生长及光合速率的诱发效率较高。在320—500、395—700、510—700和610—700 nm波段上的单位能量光照引起钝顶螺旋藻螺距变化的效率分别为0.070、0.015、0.021、0.045μm/(W·m~2)。波段320—500 nm虽然会轻微抑制钝顶螺旋藻D-0083的有效光化学效率(Fv′/Fm′)、电子传递速率(ETR)和藻蓝蛋白的荧光发射,但是却能够有效诱导其藻丝变紧促进生长。此外,钝顶螺旋藻D-0083的藻丝变紧程度、比生长速率变化与不同波段太阳辐射下藻丝体的光合性能相一致。该研究表明任何波段的光合有效辐射都能使螺旋藻藻丝螺旋变紧并引发生长和光合作用,其中以蓝光和红光的效率最高。     

螺旋藻品系Z中不同形态藻丝体的生长速率和光合色素比较

The line-shaped filaments Sp-Z(L) were isolated and cultured from Spirulina platensis Sp-Z. The growth rate of Sp-Z(L) was only 64% as much as that of SP-Z when the light intensity was 4000 Lux. The contentS (×10-3 g / g dry weight) of chlorophylls, carotenoids and phycobilins of Sp-Z(L) and Sp-Z were 20.6, 0.343, 5.00 and 24.1 0.297, 4.46, respectively. Moreover, as to the absorption spectra of the three photopigments of SP-Z(L), red shifts were observed. Therefore, after the spiral Sp-Z breeded or changed…     

阳光紫外辐射和盐胁迫对钝顶螺旋藻光合作用和形态变化的耦合效应

将钝顶螺旋藻培养在含有不同NaCl浓度（0、0．4、0．8mol·L^-1）的培养基中,并置于室外全波段太阳辐射、阳光辐射滤除uvB以及光合有效辐射（PAR）三种辐射条件下,以探讨阳光uV辐射和盐胁迫对钝顶螺旋藻的耦合效应。结果表明,阳光uv辐射显著抑制钝顶螺旋藻的光化学效率,且随着盐浓度的提高,其受抑制程度加剧。D1蛋白含量在高水平PAR和uV辐射下都明显降低,而高盐浓度（0．8mol·L^-1NaCl）导致其含量进一步下降。此外,阳光uv辐射与盐胁迫的耦合作用使得藻丝发生明显断裂。     

倍频Nd：YAG激光对钝顶螺旋藻的诱变效应

利用倍频 Nd:YAG激光 (波长 53 2 nm,功率 50 0 m W,功率密度 1 60 m W/cm2 )诱变钝顶螺旋藻 ,辐照时间为 1 5min、1 0 min、5min通过测定藻丝形态参数、叶绿素 a、β 胡萝卜素、生长速度 ,比较倍频 Nd:YAG激光对钝顶螺旋藻生长的影响。实验结果表明 :与出发株相比 ,经倍频 Nd:YAG激光辐照后 ,藻丝形态发生变化 ,藻丝长、螺旋数、螺旋长变小 ;1 5min,1 0 min辐照组出现螺旋变松驰 ;1 0 min,5min辐照组促进藻的生长和叶绿素 a含量提高 ,使生长速度提高。三个诱变时间剂量都有利于 β 胡萝卡素积累 ,含量增幅最高达 2 2 .3 %。     

紫外线辐射增加对大豆光合作用和生长的影响

通过模拟南京地区自然光中有效紫外线Ｂ和紫外线Ａ辐射,增大辐射剂量对大豆光合作用,生长及生物量形成的影响迸行了研究。３个加强的ＵＶ辐射（０．１５,０．３５,０．７０Ｗ·ｍ－２）处理均使大豆植株矮化,抑制根、茎、叶的生长及干物质的积累。在３个ＵＶ处理中,生物效应以０．７０Ｗ·ｍ－２处理力最大,０．１５Ｗ·ｍ－２处理影响最小。ＵＶ辐射匀能使大豆叶片光合作用下降。下降幅度随ＵＶ辐射强度的增大而增大,本文还对ＵＶ影响大豆生长的可能机制进行了探讨。     

补充UV-B辐射对浙贝母生长和光合作用的影响

通过模拟西安地区自然光中U V2B辐射,增大辐射剂量对浙贝母生长和光合作用的影响进行研究.3个增强的U V2B辐射2.54、4.25及5.31k J·m-2处理导致浙贝母株高、叶面积、单株干重、叶绿素含量降低,而茎粗增加.在3个U V2B处理中,生物效应以5.31k J·m-2处理为最大,2.54k J·m-2处理影响最小.同时增加的U V2B还使浙贝母的光合速率、蒸腾速率、水分利用率下降,作用效果与辐射强度呈正相关.分析认为,浙贝母对U V2B辐射具有一定的敏感性.     

钝顶螺旋藻藻种的紫外诱变初步筛选

目的:初步筛选钝顶螺旋藻藻种。方法:结合自然分离筛选和紫外诱变育种两种方法。结果:得到4株钝顶螺旋藻突变株Z3、Z7、Z9和Z10。结论:与出发株(螺旋数一般5~7个)相比:藻丝长度均明显变长,螺旋数超过40个,形体较大,易于采收,且其藻胆蛋白含量高于出发藻株6.0%,生长速度较快,上浮性较好,值得进一步研究利用。     

葡萄糖和乳糖对钝顶螺旋藻生长和色素含量的影响

葡萄糖和乳糖能促进钝顶螺旋藻生物量的增加,降低叶绿素a和类胡萝卜素含量,但对藻胆蛋白含量的影响不显著。比较而言,乳糖更有利于钝顶螺旋藻混养生物量的提高。     

MIXOTROPHIC GROWTH MODIFIES THE RESPONSE OF SPIRULINA (ARTHROSPIRA) PLATENSIS (CYANOBACTERIA) CELLS TO LIGHT

Spirulina (Arthrospira) platensis (Nordstedt) Geitler cells grown under mixotrophic conditions exhibit a modified response to light. The maximal photosynthetic rate and the light saturation value of mixotrophic cultures were higher than those of the photoautotrophic cultures. Dark respiration and light compensation point were also significantly higher in the mixotrophically grown cells. As expected, the mixotrophic cultures grew faster and achieved a higher biomass concentration than the photoautotrophic cultures. In contrast, the growth rate of the photoautotrophic cultures was more sensitive to light. The differences between the two cultures were also apparent in their responses to exposure to high photon flux density of 3000 μmol·m ^{− 2}·s ^{− 1}. The light-dependent O₂ evolution rate and the maximal efficiency of photosystem II photochemistry declined more rapidly in photoautotrophically grown than in mixotrophically grown cells as a result of exposure to high photon flux density. Although both cultures recovered from the high photon flux density stress, the mixotrophic culture recovered faster and to a higher extent. Based on the above results, growth of S. platensis with a fixed carbon source has a significant effect on photosynthetic activity.     

COMBINED EFFECTS OF ULTRAVIOLET RADIATION AND TEMPERATURE ON MORPHOLOGY,PHOTOSYNTHESIS, AND DNA OF ARTHROSPIRA (SPIRULINA) PLATENSIS (CYANOPHYTA)1

Natural levels of solar UVR were shown to break and alter the spiral structure of Arthrospira (Spirulina) platensis (Nordst.) Gomont during winter. However, this phenomenon was not observed during summer at temperatures of ～30°C. Since little has been documented on the interactive effects of solar UV radiation (UVR; 280–400 nm) and temperature on cyanobacteria, the morphology, photosynthesis, and DNA damage of A. platensis were examined using two radiation treatments (PAR [400–700 nm] and PAB [PAR + UV‐A + UV‐B: 280–700]), three temperatures (15, 22, and 30°C), and three biomass concentrations (100, 160, and 240 mg dwt [dry weight] · L^?1). UVR caused a breakage of the spiral structure at 15°C and 22°C, but not at 30°C. High PAR levels also induced a significant breakage at 15°C and 22°C, but only at low biomass densities, and to lesser extent when compared with the PAB treatment. A. platensis was able to alter its spiral structure by increasing helix tightness at the highest temperature tested. The photochemical efficiency was depressed to undetectable levels at 15°C but was relatively high at 30°C even under the treatment with UVR in 8 h. At 30°C, UVR led to 93%–97% less DNA damage when compared with 15°C after 8 h of exposure. UV‐absorbing compounds were determined as negligible at all light and temperature combinations. The possible mechanisms for the temperature‐dependent effects of UVR on this organism are discussed in this paper.     

MORPHOLOGICAL REVERSION OF SPIRULINA (ARTHROSPIRA) PLATENSIS (CYANOPHYTA): FROM LINEAR TO HELICAL1

The cyanobacterium Spirulina Turpin is characterized by its regularly coiled trichomes. Under some conditions, its helical filaments can convert to abnormal morphologies, such as irregularly curved and even linear shapes, that had been considered as a permanent degeneration that could not be reversed. However, here we found that the linear filaments of Spirulina platensis Geitler could spontaneously revert to the helical form with the same morphology as the original filaments. Further studies showed that the ultrastructural, physiological, and biochemical characteristics of linear filaments were different from those of the original filaments, whereas they were the same for the reverted and the original filaments. The SDS‐PAGE analysis revealed at least four proteins or subunits related to Spirulina morphogenesis: The 21.9‐kDa and the 20.3‐kDa proteins were highly expressed in the helical filaments, whereas the 52.0‐kDa and the 31.8‐kDa proteins were highly expressed in the linear filaments. The random amplified polymorphic DNA analysis with 96 random primers showed that the genetic background of the reverted filaments was the same as that of the original filaments but distinct from that of the linear filaments. The results indicated that linear filaments of Spirulina could revert to the original morphology under certain conditions, and their other distinctive traits were regained.     

利用CASA模型估算我国植被净第一性生产力

基于地理信息系统和卫星遥感应用技术,利用CASA模型估算了我国1997年植被净第一性生产力及其分布。结果表明：1997年我国植被净第一性生产力为1．95PgC,约是世界陆地植被年净第一性生产力的4．0％;我国植被净第一性生产力的主要分布趋势是从东南沿海向西北逐渐减小,其中海南岛南部、云南西南部、青藏高原东南部的热带雨林和季雨林地区植被年净第一性生产力最大,达900gC.m^2.a^-1以上,而西部塔克拉玛干沙漠地区植被年净第一性生产力最小,不足10gC.m^-2.a^-1。     

静止和充气培养条件下短期紫外辐射对钝顶螺旋藻光化学效率的影响

为了研究短期太阳紫外辐射对钝顶螺旋藻的影响,作者将静止和充气培养的藻体,暴露在全波长太阳辐射PAB(PAR UVA UVB),去除UVB辐射PA(PAR UVA)及切断所有紫外辐射的光合有效辐射P(PAR)三种光处理条件下,测定了其光化学效率的变化。结果表明,紫外辐射(UVP)及光合有效辐射(PAR)均能导致钝顶螺旋藻的光化学效率降低,表现出了明显的光抑制,但是,UVR可导致更大程度的光抑制。充气培养条件下,与早晨(07:00)初始值相比,PAR导致了11%~20%的光抑制,而UVR(PAB-P)所产生的额外光抑制占9%~31%;静止培养条件下,UVR的存在使得螺旋藻的光化学效率趋近于零(无法检出)。在两种培养条件下,藻细胞所受最大光抑制均发生在中午,下午(17:00)表现出不同程度的恢复。紫外辐射使得类胡萝卜素及藻蓝蛋白与叶绿素a含量的比例增大。与PAB和P相比,PA处理使得螺旋藻类胡萝卜素和藻蓝蛋白与叶绿素含量之比明显升高,UVA可能会诱导类胡萝卜素及藻蓝蛋白的合成。     

PARTIAL PURIFICATION AND CHARACTERIZATION OF A CALCIUM‐DEPENDENT ALKALINE PHOSPHATASE FROM THE CYANOBACTERIUM ARTHROSPIRA PLATENSIS 1

In the present study, Triton X‐114 (TX‐114) is used to extract and partially purify alkaline phosphatase (ALP) from a membranous fraction of Arthrospira platensis Gomont containing cell wall, plasma membrane, thylakoids, and sheath. TX‐114 has a double effect: solubilizing cell components to liberate the enzyme and, after phase partitioning, removing chl and other pigments present in the crude extract. The recovery of the enzyme in the aqueous phase suggests the overall hydrophilic character of this enzyme. ALP was kinetically characterized at pH 11.0 using p‐nitrophenyl phosphate as substrate, giving a K_m value of 1.7 mM. Orthovanadate was seen to be a competitive inhibitor of ALP, with a K_i of 0.8 mM. The enzyme was almost completely inactivated in the presence of 70 μM EDTA, although the addition of Ca²⁺ reverted this inactivation; these results indicate that ALP from A. platensis is a calcium‐dependent metalloenzyme. When the effect of Ca²⁺ was investigated in detail, a value of 0.067 μM^?1 for the affinity constant was obtained. The enzyme was histochemically localized in the cytoplasm, cell wall, and sheath using the enzyme‐labeled fluorescent substrate (ELF) method. It is assumed that the same enzyme is either soluble in the cytoplasm and in some way “trapped” in the cell wall or in the sheath. ALP localization within the sheath and the subsequent release of phosphorus (P) may benefit the neighboring cells surrounding this layer.     

卡特拉鱼形态,食性和生长的研究

观测卡特拉鱼的形态特征和1—3龄鱼主要可量性状及其比例的变动。1—3龄鱼除主食商品饲料外,同时也食较大比例的浮游生物。着重对浮游生物的种类和比例进行了分析。肠长与体长呈直线相关。Y=6.38X-89.95。1—4龄鱼体长和体重相对生长率和生长指标都随年龄增加而逐渐下降。体长与体重呈曲线相关。W=0.00002261L~(3.0569)。采用 Von.Bertalanffy 生长方程分析其生长特性。方程参数 L_∞=821.2mm,W_∞=19616.6g,t_0=0.6年,K=0.3。体长生长不具拐点,生长速度随年龄增加而递减;体重生长具拐点,其值4.3年。此时体重生长速度达最大值。4、3龄前是生长旺盛期,此后进入生长缓慢期。     

水华鱼腥藻生长与光合作用对大气CO2浓度升高的响应

 为了探讨大气CO2浓度升高对水华藻类的影响,利用水华鱼腥藻(Anabena flos_aquae)作为实验材料,研究了大气CO2浓度加倍对其生长和光合作用的影响,结果显示大气CO2浓度升高导致水华鱼腥藻的生物量、光饱和光合速率、光合效率和光系统II的光化学效率（Fv/Fm）明显提高,但对暗呼吸速率和光饱和点没有明显影响。CO2加倍条件下藻细胞光合作用对无机碳的亲和力降低,表明其利用HCO-3的能力受到抑制。     

螺旋藻及其水提物对肠道菌群体外生长的影响

体外观察螺旋藻及其水提物对肠道菌群生长的影响。结果表明 ,螺旋藻及其水提物对双歧杆菌和乳杆菌和生长具有显著的促进作用 (培养 48h,P<0 .0 0 1) ,对肠道其他菌亦有不同程度的促进作用 ,而对大肠埃希菌的促生长作用不显著 (P>0 .0 5 )。