H2 PRODUCTION BY ANABAENA VARIABILIS MUTANT IN COMPUTER CONTROLLED TWO-STAGE AIR-LIFT TUBULAR PHOTOBIOREACTOR

A 4.34 liter two-stage air-lift photobioreactor incorporatingAnabaena variabilis ATCC29413 mutant PK84 was used to study H₂ production. Results showed that H₂ production increased with increasing light intensity from 47 μE/(m²·s) up to 190 μE/(m²·s), but that further increase of light intensity decreased the H₂ production because of the inhibition due to the high pO₂. The data also indicated that longer argon gas charge resulted in more H₂ produced due to the increase of nitrogenase activities and heterocyst frequency, and that more than 1.3 L net H₂ was produced from this computer controlled photobioreactor.     

Allelopathic effects of macroalga <Emphasis Type="Italic">Corallina pilulifera</Emphasis> on the red-tide forming alga <Emphasis Type="Italic">Heterosigma akashiwo</Emphasis> under laboratory conditions

Over the past few years, harmful algal blooms (HABs), such as red tides, have been frequently observed in coastal zones worldwide. The natural allelopathic interactions among macroalgae and red tide microalgae can alter the structure and succession of aquatic ecosystems. We investigated the influence of four environmental factors (temperature, salinity, light, and pH) on the allelopathic effects of the macroalgae Corallina pilulifera on red-tide forming Heterosigma akashiwo under laboratory conditions. Each of the factors had four levels: temperature (15, 20, 25, and 30°C), salinity (10, 20, 30, and 40), light (20, 100, 200 and 400 μmol/(m²?s)), and pH (5.5, 7, 8.5, and 10. Two-factor experiments were designed for each two environmental factors, with six combination treatments (temperature-salinity, temperature-light, temperature-pH, salinity-light, salinity-pH, and light-pH). Results showed that the allelopathic effect was significantly influenced by temperature, salinity, light, and pH. As single factors, the low temperature (15°C), low salinity (10), high-intensity light (400 μmol/(m²?s)), and high pH (10) treatments substantially enhanced the allelopathic effect. The strongest allelopathic effect of C. pilulifera on H. akashiwo was observed under the following treatments: 15°C and salinity of 40, 25°C and pH 10, 25°C with medium- to high-intensity light at 200–400 μmol/(m 2 ?s), 400 μmol/(m²?s) and salinity of 10, 400 μmol/(m²?s) and pH 10, and pH 10 with a salinity of 40.     

Abiotic factors in colony formation: effects of nutrition and light on extracellular polysaccharide production and cell aggregates of Microcystis aeruginosa

Colony morphology is important for Microcystis to sustain a competitive advantage in eutrophic lakes. The mechanism of colony formation in Microcystis is currently unclear. Extracellular polysaccharide (EPS) has been reported to play an important role in cell aggregate formation of some phytoplankton. Microcystis aeruginosa was cultivated under varied abiotic conditions, including different nutrient, light, and temperature conditions, to investigate their effects on EPS production and morphological change. The results show that nutrient concentration and light intensity have great effects on EPS production in M. aeruginosa. There was a considerable increase in EPS production after M. aeruginosa was cultivated in adjusted culture conditions similar to those present in the field (28.9mg C/L, 1.98mg N/L, 0.65mg P/L, light intensity:100 μmol/(m2s)). These results indicate that abiotic factors might be one of the triggers for colony formation in Microcystis.     

Removal of phenol by Isochrysis galbana in seawater under varying temperature and light intensity

Phenol is a common industrial chemical produced and transported worldwide largely. Therefore, accidental spillage of phenol in the ocean causes an increasing concern. Microalgae are promising to remove phenol from marine waters. However, temperature and light intensity are two main factors that markedly influence biodegradation in marine environments. In this study, a marine golden alga Isochrysis galbana is selected to research the removal of phenol under different temperatures (10–30°C) and light intensities (0–240 µmol/(m2·s)). The results show that the most suitable temperature and light intensity for phenol removal are 20°C and 180 µmol/(m2·s), respectively, and 100 mg/L of phenol can be completely removed by microalga in 24 h at these conditions. I. galbana can also remove phenol under dark and low-temperature conditions. The removal of phenol by I. galbana at diverse temperatures and light intensities conform to first-order kinetics, and the process under dark conditions conform to zero-order kinetics. Thus, I. galbana can be used in the in-situ bioremediation of polluted seawater by phenol.     

Induction and cultivation of cloned filaments of Polysiphonia urceolata (Rhodomelaceae, Rhodophyta)

A filamentous clone of Polysiphonia urceolata was regenerated from segments cut from the fronds of gametophytes. Unlike wild thalli with short virgate branchlets, the clone was filamentous with few branches. Many transparent trichoblasts arose from pericentral cells during the induction culture, but these were seldom observed during normal growth. The trichoblasts were uniseriate, often colorless, and formed lobed rhizoids rapidly when they came into contact with solid substrates. In addition to morphological characteristics, the photosynthetic properties and growth conditions of the clone differed from those of the mother plant. Cross-gradient light and temperature culture experiments revealed that the most favorable conditions for culture of the filamentous clone were 22°C and 95-120 μE/(m2-s) light intensity. The photosynthetic light saturation value for filaments was approx. 100 μE/(m2-s), which is far lower than that of wild thalli. These results could be used to develop techniques for mass cultures of P. urceolata in photobioreactors for production of seed stock or bioactive products.     

Photobehaviors ofthe calanoid copepod Calanus sinicus from the Yellow Sea to visible and UV-B radiation as a function of wavelength and intensity

The effects of wavelength-specific visible light,white light,and ultraviolet-B(UV-B,280-31 5 nm)on selected behaviors,grazing rate,spawning rate,and hatching rate of the marine copepod Calanus sinicus collected from the Yellow Sea were studied.Calanus s inicus placed in a partitioned experimental sy stem responded positively phototaxis to blue-cyan and yellow light but negatively to orange light and UVB.No obvious dodge activity was found among C.s inicus irradiated with0.005 mW/cm~2 UV-B.Under0.20,0.30 and 0.50 mW/cm~2 UV-B radiation,the lethal half times of individuals were 30.47,2.86,and1.96 h,respectively.Grazing of C.sinicus was restrained at0.10 mW/cm~2 UV-B,whereas yellow-red light stimulated grazing.Egg production rate was highest at a white-light intensity of 1.58 mW/cm~2,with an average rate of 10.04 eggs/(female d).These results are consistent with the observed phenomenon that C.sinicus in the Yellow Sea mostly spa.wn near dawn.Our results indicate that light intensity and spectrum are important factors affecting the diel vertical migration of C.sinicus under natural conditions in the Yellow Sea.     

Grazing of Salpa thompsoni on phytoplankton in summer in the Prydz Bay region, Antarctica

During the CHINARE-Ⅺ cruise in austral summer of 1998/1999, the abundance and feeding activity of Salps thompsoni were investigated in the Prydz Bav region. Salps samples were collected by vertical tows from the depth of 200 m to the surface with a conical net of 330 μm mesh-size. At Ⅵ-3 station, the grazing rates were studied by the gut fluorescence method and culture experiments. S. Thompsoni was mainly distributed in the northern part of the survey area, and its maximum densities reached to 2795 ind. · 1000 m-3. A dramatic decrease in salp stock was observed at the Marginal Ice Zone. The results of the feeding experiments at the Ⅵ-3 show that the gut pigment contents of S. thompsoni ranged from (0. 14 - 1.27) μig ind. -1(average 0. 98 μg ind.-1). The individual ingestion rate is 7. 9 μg ind. -1 · day-1, and the filtration rate is 28 L ind. -1 · day-1 Through the daily grazing rate of S. thompsoni, which takes account of less than 1% of the phytoplankton standing stock, it shows arelatively higher grazing impress on the primary production (72. 2 % ).     

一种户外开放式微藻培养体系优化

【目的】建立可用于大规模培养的户外开放式微藻培养体系。【方法】设计一种微藻平面开放浅层培养(Flat,open and shallow,FOS,简称浮法)体系,以小球藻(Chlorella sorokiniana)为模式藻种,探讨温度、光照、pH值和培养基营养成分等因素在该培养体系中对小球藻生长的影响,开展900 L体系的户外培养试验。【结果】浮法体系主要由塑料袋和垫板组成,在该培养体系中的小球藻在20~40℃范围内均可生长,最适生长温度为30~35℃。小球藻生长有明显的照度依赖性,无光时几不生长,随着照度升高,生长速度加快,在较高的照度下表现有光饱和现象。以TAP为基础培养基,在碳源或氮源缺乏时小球藻几不生长。pH 7.5左右有利于小球藻生长。900 L体系的户外培养试验的生物量(干物质得率)为0.15 g/(L·d)。【结论】在此新型户外平面开放浅层微藻培养体系中,温度、照度、pH值及营养成分等对小球藻的生长均有不同程度的影响。该体系有成本低、操作简便、容易控制、自然资源利用率高等特点,有大面积推广潜力。     

COMBINED EFFECTS OF TEMPERATURE, IRRADIANCE AND SALINITY ON GROWTH OF DIATOM SKELETONEMA COSTATUM

ＩＮＴＲＯＤＵＣＴＩＯＮＶａｒｉｏｕｓｃａｕｓａｔｉｖｅｆａｃｔｏｒｓ,ｓｕｃｈａｓｉｎｃｒｅａｓｅｄｓｃｉｅｎｔｉｆｉｃａｗａｒｅｎｅｓｓ,ｕｔｉｌｉｚａｔｉｏｎｏｆｃｏａｓｔａｌｗａｔｅｒｓｆｏｒａｑｕａｃｕｌｔｕｒｅ,ｅｕｔｒｏｐｈｉｃａｔｉｏｎａｎｄｃｙｓｔｔｒａｎｓｐｏｒｔａｔｉｏｎ (Ｈａｌｌｅｇｒｅａｆｆｅｔａｌ.,1 995)ｈａｓｌｅｄｔｏｅｘｔｅｎｓ ｉｖｅｓｔｕｄｉｅｓｏｎｔｈｅｇｌｏｂａｌｉｎｃｒｅａｓｅｉｎＨＡＢ (ＨａｒｍｆｕｌＡｌｇａｌＢｌｏｏｍ) .ＹｅｔｔｈｅＨＡＢｍｅｃｈａｎｉ…     

Effects of salinity, light and temperature on growth rates of two species of Gracilaria （Rhodophyta）

Effects of temperature, salinity and light intensity on growth rates of Gracilaria lichenoides and G. tenuistipitata var. liui Zhang et Xia were tested. Eight to ten levels of each factor were first tested separately. The best growth rate was obtained under the conditions of 32°C, 30 and 240 μmol/(m²·s) for G. lichenoides, and 24°C, 20 and 200 μmol/(m²·s) for G. tenuistipitata, respectively. Then a uniform design was used to evaluate the optimal combinations of the three factors. The best conditions for the highest daily specific growth rates (% increase in wet weight) are determined to be 31.30°C, 32.10, and 287.23 μmol/(m²·s) for G. lichenoides (16.26%/d), and 25.38°C, 21.10, and 229.07 μmol/(m²·s) for G. tenuistipitata (14.83%/d), respectively. Supported by the 908 Special Program (908-02-04-07), the National Basic Research Program of China (973 Program, No. 2006CB400608), and K. C. Wong Magna Fund in Ningbo University     

Effects of iron electrovalence and species on growth and astaxanthin production of Haematococcus pluvialis

To increase the cell concentration and the accumulation of astaxanthin in the cultivation of Haematococcus pluvialis, effects of different iron eleetrovalencies (Fe2+-EDTA and Fe3+-EDTA) and species (Fe-EDTA, Fe(OH)32x and FeC6H5O7) addition on cell growth and accumulation of astaxanthin were studied. Results show that different iron electrovalencies have various effects on cell growth and astaxanthin accumulation of H. pluvialis. Compared with Fe3+-EDTA, Fe2+-EDTA stimulate more effectively the formation of astaxanthin. The maximum astaxanthin content (30.70 mg/g biomass cell)was obtained under conditions of 18 μmol/L Fe2+-EDTA, despite the lower cell density (2.3x105 cell/ml)in such condition. Fe3+-EDTA is more effective than Fe2+-EDTA in improving the cell growth. Especially,the maximal steady-state cell density, 2.9x105 cell/ml was obtained at 18 μmol/L Fe3+-EDTA addition. On the other hand, all the various species of iron (EDTA-Fe, Fe(OH)32x, FeC6H5O7) are capable to improve the growth of the algae and astaxanthin production. Among the three iron species, FeC6H5O7 performed the best. Under the condition of a higher concentration (36 μmol/L) of FEC6H5O7, the cell density and astaxanthin production is 2 and 7 times higher than those of iron-limited group, respectively. The present study demonstrates that the effects of the stimulation with different iron species increased in the order of FeC6H5O7, Fe(OH)32x/x and EDTA-Fe.     

Emissions of biogenic sulfur gases (H<Subscript>2</Subscript>S,COS) from <Emphasis Type="Italic">Phragmites australis</Emphasis> coastal marsh in the Yellow River estuary of China

Emissions of biogenic sulfur gases (hydrogen sulfide (H₂S) and carbonyl sulfide (COS)) from Phragmites australis coastal marsh in the Yellow River estuary of China were determined during April to December in 2014 using static chamber-gas chromatography technique with monthly sampling. The results showed that the fluxes of H₂S and COS both had distinct seasonal and diurnal variations. The H₂S fluxes ranged from 0.09 μg/(m²·h) to 7.65 μg/(m²·h), and the COS fluxes ranged from–1.10 μg/(m²·h) to 3.32 μg/(m²·h). The mean fluxes of H₂S and COS from the P. australis coastal marsh were 2.28 μg/(m²·h), and 1.05 μg/(m²·h), respectively. The P. australis coastal marsh was the emission source of both H₂S and COS over the whole year. Fluxes of H₂S and COS were both higher in plant growing season than in the non-growing season. Temperature had a dramatic effect on the H₂S emission flux, while the correlations between COS flux and the environmental factors were not found during sampling periods. More in-depth and comprehensive research on other related factors, such as vegetation, sediment substrates, and tidal action is needed to discover and further understand the key factors and the release mechanism of sulfur gases.     

利用海洋疏浚泥生产轻质陶粒的研究

为将疏浚泥转化为可再利用的材料,以减少疏浚泥海洋倾倒量,利用烧结技术将疏浚泥转 化为建筑材料———轻质陶粒进行再利用,把掺疏浚泥的混合料投入应用性试生产。结果表明,当 混合料中疏浚泥与黏土的比例达到1∶2或1∶3时,烧结温度1160℃,焙烧效果较好,所得陶粒的 颗粒密度较低;陶粒产品的表观密度<450kg/m3,筒压强度>1.2MPa,产品性能符合国家标准;生 产成本基本上没有增加,并可节约耕地,产生一定的环境效益和社会效益。     

Effects of shrub on runoff and soil loss at loess slopes under simulated rainfall

Improved understanding of the effect of shrub cover on soil erosion process will provide valuable information for soil and water conservation programs.Laboratory rainfall simulations were conducted to determine the effects of shrubs on runoff and soil erosion and to ascertain the relationship between the rate of soil loss and the runoff hydrodynamic characteristics.In these simulations a 20° slope was subjected to rainfall intensities of 45,87,and 127 mm/h.The average runoff rates ranged from 0.51 to 1.26 mm/min for bare soil plots and 0.15 to 0.96 mm/min for shrub plots.Average soil loss rates varied from 44.19 to 114.61 g/(min·m~2) for bare soil plots and from 5.61 to 84.58 g/(min·m~2) for shrub plots.There was a positive correlation between runoff and soil loss for the bare soil plots,and soil loss increased with increased runoff for shrub plots only when rainfall intensity is 127 mm/h.Runoff and soil erosion processes were strongly influenced by soil surface conditions because of the formation of erosion pits and rills.The unit stream power was the optimal hydrodynamic parameter to characterize the soil erosion mechanisms.The soil loss rate increased linearly with the unit stream power on both shrub and bare soil plots.Critical unit stream power values were 0.004 m/s for bare soil plots and 0.017 m/s for shrub plots.     

pH值和氧化剂对硫化锑氧化溶解的影响机制

矿山开采活动影响下辉锑矿的氧化溶解是影响岩-土-水环境介质中锑的迁移转化及其环境效应的重要过程。目前对于辉锑矿溶解的研究主要关注动力学特征,对于它氧化溶解的途径、环境因素的影响、锑的释放规律等重要问题的认识还不明确。为探究碳酸盐岩矿区地下水中锑释放过程,选取重要环境因素pH值和Fe（Ⅲ）,采用单因素控制条件下的批实验方法,精细刻画避光条件下辉锑矿（Sb₂S₃）氧化溶解速率及Sb和S氧化产物的组成特征。研究结果表明,Sb₂S₃的氧化溶解是一个产酸的过程,Sb和S的释放速率、途径和产物特征受pH值和Fe（Ⅲ）的显著影响。Sb₂S₃的氧化溶解速率由快变慢后趋于平衡,初始反应速率的量级为10-8 mol/（m2·s）,平衡反应速率的量级为10-10 mol/（m2·s）。Sb的释放氧化速率随pH值的增加而增加,强碱条件下最有利于Sb的释放和氧化。强酸条件下,H₂S、SO₂气体逸出和S（0）的沉淀促进了Sb₂S₃的溶解,Sb（Ⅲ）和S（0）为主要产物。中性条件下,溶解形成的HS-经逐步氧化生成SO₄2-和少量S₂O₃2-,Sb（Ⅲ）和Sb（Ⅴ）含量相近。强碱条件下,SbS₃3-和S_x-的生成显著提升了Sb₂S₃的氧化溶解速率,Sb（Ⅴ）和S₂O₃2-是主要产物。Fe（Ⅲ）单独氧化作用时,Sb（Ⅴ）和S（0）是主要产物,锑释放的表观速率无显著提升,可能与SbOCl和S（0）的生成有关。研究表明,O₂能够协同Fe（Ⅲ）氧化Sb₂S₃,但以Fe（Ⅲ）的作用为主导。本研究揭示了Sb₂S₃在不同pH值及氧化剂条件下氧化溶解的产物组成特征,提出了不同环境因素影响下的氧化溶解途径,证明碳酸盐岩天然缓冲地层更有利于锑的释放与氧化,岩溶地下水中锑诱发的环境效应会更为严重。      

不同条件下波吉卵囊藻对氨氮的吸收速率

在实验室条件下模拟多种氮源共存的虾池水环境,利用稳定同位素示踪剂,研究温度、光照、盐度、pH、藻浓度对波吉卵囊藻氨氮吸收速率的影响。结果表明:温度、光照和藻浓度对波吉卵囊藻氨氮吸收速率影响极显著(P<0.01)。当温度为20℃,照度为4 500 lx,藻浓度为5.5×105/mL,波吉卵囊藻对氨氮均有最大的吸收速率,分别为1.114、1.400、1.482μg g-1 h-1。单因素方差分析得出波吉卵囊藻吸收氨氮的最优组合为:温度20℃,照度4 500lx,盐度15,pH 7.5,藻浓度5.5×105/mL。可通过对环境因子的调控,提高波吉卵囊藻对水体中氨氮的吸收速率。     

Spatiotemporal distribution of protozooplankton and copepod nauplii in relation to the occurrence of giant jellyfish in the Yellow Sea

The occurrence of the giant jellyfish, Nemopilema nomurai, has been a frequent phenomenon in the Yellow Sea. However, the relationship between the giant jellyfish and protozoa, in particular ciliates, remains largely unknown. We investigated the distribution of nanoflagellates, ciliates, Noctiluca scintillans, and copepod nauplii along the transect 33~N in the Yellow Sea in June and August, 2012, during an occurrence of the giant jellyfish, and in October of that year when the jellyfish was absent. The organisms studied were mainly concentrated in the surface waters in summer, while in autumn they were evenly distributed in the water column. Nanoflagellate, ciliate, and copepod nauplii biomasses increased from early June to August along with jellyfish growth, the first two decreased in October, while N. scintillans biomass peaked in early June to 3 571 pg C/L and decreased in August and October. In summer, ciliate biomass greatly exceeded that of copepod nauplii （4.61-15.04 ~tg C/L vs. 0.34-0.89 pg C/L）. Ciliate production was even more important than biomass, ranging from 6.59 to 34.19 ~tg C/（L.d） in summer. Our data suggest a tight and positive association among the nano-, micro-, and meso-zooplankton in the study area. Statistical analysis revealed that the abundance and total production of ciliate as well as loricate ciliate biomass were positively correlated with giant jellyfish biomass, indicating a possible predator-prey relationship between ciliates and giant jellyfish. This is in contrast to a previous study, which reported a significant reduction in ciliate standing crops due to the mass occurrence ofN. nomurai in summer. Our study indicates that, with its high biomass and, in particular, high production ciliates might support the mass occurrence of giant jellyfish.     

东海盆地西湖凹陷不同构造带原油陆源生物标志化合物特征及其指示意义

利用地球化学分析手段,对西湖凹陷黄岩构造带、平北地区以及宁波构造带的16个轻质油样品进行了分析。原油中富含反映陆源高等植物输入的生物标志化合物,尤其是源于被子植物、裸子植物及蕨类植物的三环、四环二萜类及其芳构化产物,而反映水生低等植物输入的生物标志化合物含量较低。不同构造带间原油中这些化合物的分布特征具有明显差异,如异海松烷/nC₂₀、异海松烷/（异海松烷+16β（H）扁枝烷）、1,2,5-三甲基萘/1,3,6-三甲基萘、1,7-二甲基菲/（惹烯+1,7-二甲基菲）等。这些差异指示了宁波构造带与平北地区原油裸子植物输入较多,蕨类植物及被子植物输入较少,而黄岩构造带原油蕨类植物输入较多,被子植物与裸子植物较少的特点。研究中利用全油色谱-质谱将原油饱和烃与芳烃组分建立联系,提出（异海松烷+1,7-二甲基菲）/（惹烯+16β（H）扁枝烷）作为反映西湖凹陷轻质原油生源构成的指标,而该参数与全油碳同位素值的正相关关系证明了裸子植物树脂对西湖凹陷轻质油的重要成烃贡献。      

Photochemical production of dissolved inorganic carbon from suwannee river humic acid

The photochemical mineralization of dissolved organic carbon(DOC) to dissolved inorganic carbon(DIC) is a key process in carbon cycling.Using a Suntest CPS solar simulator,Suwannee River humic acid(SRHA) was photooxidated to examine the effects of O2 levels,the wavelength of incident light,and the concentration of Fe on the photoproduction of DIC.Increasing the O2 abundance enhanced photodegradation of SRHA.The rate of DIC photoproduction under air saturation in the first 24 h(4.40 μmol/(L h)) was increased...     

微酸性电解水结合复合保鲜剂对凡纳滨对虾冷藏期间蛋白特性影响

【目的】研究微酸性电解水(SAEW)结合迷迭香提取物(RE)-柠檬酸(CA)复合保鲜剂处理对凡纳滨对虾(Litopenaeus vannamei)冷藏期间蛋白特性变化影响,探讨此法用于虾类贮藏保鲜的效果。【方法】将样品分别经SAEW、质量分数4%RE+质量分数1%CA(RC)、SAEW结合RC(SAEW+RC)和无菌水(CK)处理10 min后,自然沥干15 min,装入PE保鲜袋于(4±1)℃冰箱中保藏,每2 d测定样品的pH值、总挥发性盐基氮(TVB-N)、总巯基含量、Ca²⁺-ATPase活性、化学键、肌原纤维小片化指数(MFI)与内源荧光强度(IFI)等指标,并结合聚丙烯酰胺凝胶电泳(SDS-PAGE)进行综合分析。【结果】复合处理能延缓凡纳滨对虾贮藏期间pH与TVB-N值的升高,抑制总巯基含量下降,CK、RC、SAEW与SAEW+RC组样品的Ca²⁺-ATPase活力分别由初始0.16、0.17、0.17与0.17μmol/(mg·min)降至0.12、0.13、0.12与0.14μmol/(mg·min),MFI值较初始值上升1.88、1.73、1.76和1.54倍,可见SAEW+RC对延缓Ca²⁺-ATPase活性下降与MFI值的上升有较好作用。同时,SAEW+RC处理还能减缓蛋白质分解、氧化和变性,保持蛋白质化学键与IFI值的相对稳定。【结论】微酸性电解水结合复合保鲜剂处理能较好抑制凡纳滨对虾冷藏期间的蛋白质氧化分解,延缓其品质劣变。