转光膜在雨生红球藻养殖上的应用

通过对雨生红球藻在不同光质条件下生长的比较,确定了红色光有利于藻生长,进而用2.5 L气升式光照反应器在转光膜及普通PE膜下培养藻进行对比,结果显示雨生红球藻生物量、色素、光合活性等几项生物指标在转光膜条件下明显高于普通PE膜. 在气升式反应器内培养的藻细胞,接种9 d,虾青素含量可达3.57 mg/L,叶绿素浓度达到12.42 mg/L,干重提高8.8%以上.     

产烃葡萄藻在气升式光生物反应器中的分批补料培养

在3 L气升式光生物反应器中进行了产烃葡萄藻的培养. 批式培养时，葡萄藻消耗氮、磷的速度较快，培养液中氮、磷营养盐的缺乏限制了藻细胞进一步生长和增殖. 采取分批补料方式，使培养液中KNO3和K2HPO4浓度分别维持在100和30 mg/L，可克服氮、磷限制问题. 与批式培养相比，生物量从1.3 g/L增加到1.9 g/L，烃含量从占细胞干重的22%提高到29%，从而使烃产量从0.286 g/L增加到0.551 g/L，提高了92.6%.     

转基因聚球藻7942培养中光传递及其对细胞生长的影响

对转人源胸腺素a1基因聚球藻7942光生物反应器分批培养过程中光的分布、平均光强变化及其对藻细胞生长的影响进行了分析. 结果表明，Hyperbolic光衰减模型较之Lambert-Beer光衰减模型能更好地描述转基因聚球藻7942培养液中的光衰减；随着藻细胞密度的增加，光生物反应器内平均光强不断减小，藻细胞的光能比吸收速率也不断降低，反应器中“暗区”体积不断加大；培养时间0~1.5 d，藻细胞能获得充足光能，因而呈指数生长；1.5 d后藻细胞处于光限制，比生长速率不断下降，但体积光能吸收速率达到最大并保持恒定，藻细胞进入线性生长期；5 d后光生物反应器“暗区”体积超过了反应器总体积的50%，藻细胞吸收的光能用于维持的比例不断增加，从而导致生长速率下降；培养8 d，转基因聚球藻7942中人源胸腺素a1表达量为4.53 mg/L.     

通气量和CO2对Nannochloropsis sp.在光生物反应器中的生长和EPA合成的影响

实验考察了在气升式内环流光生物反应器中通气量、CO2含量等培养条件对Nannochloropsis sp.生长及EPA合成的影响. 结果表明,在气升式内环流光生物反应器中培养,Nannochloropsis sp.生长速率显著提高. 培养8 d,Nannochloropsis sp.生物量(干重)可达857 mg/L,是摇床培养的2倍. 在一定范围内,Nannochloropsis sp.的生长速率随通气量的增加而增加,在本实验条件下,通气量为500 mL/min时生长最快,而过高的通气量则对Nannochloropsis sp.的生长没有促进作用. 在通气中含1%(j) CO2时,可加快藻细胞的生长,最大生长速率可达不配加CO2时的1.8倍. 通气量和CO2对Nannochloropsis sp.细胞内总脂肪酸及EPA的积累有显著影响. 在通气量为400 mL/min及CO2含量为0.5%时,培养液中EPA产量最高,达到39.0 mg/L.     

小球藻在内光源气升式反应器中的培养工艺优化

为探索小球藻在内光源气升式光生物反应器中的培养工艺,本文采用自行设计的50L内光源气升式反应器为实验装置,以藻细胞密度为考察指标,采用单因素法分别考察了内置光源波长、光源强度、光暗周期以及二氧化碳供应量对小球藻生长的影响。在此基础上,利用响应面设计法对工艺条件进行了优化,优化结果为：反应器内置光源为红蓝光,光照强度9615lux,光暗周期17.5h：6.5h,二氧化碳通气量为30L/h。在该优化条件下,进行3次验证实验,经15天培养,小球藻的收获藻细胞密度均值为5.48×10⁷ cells/mL,与预测值5.5×10⁷ cells/mL相近。收获小球藻干重为1.21g/L,相较优化前提高了157%。该结果为内光源气升式反应器在微藻培养的应用提供了重要的参考。     

用于微藻培养的气升式光生物反应器

基于微藻光自养培养特性 ,构建了具有较大面积体积比的 15 L内外光源相结合的气升式光生物反应器 ,考察了两种不同形态藻细胞培养体系中 ,光强随细胞浓度及光程距离衰减的规律 ,得到了描述光衰减的数学关系式 ,即在鱼腥藻 712 0培养体系中为 I=I0 exp[- (0 .0 131+0 .987OD750 )·L],在聚球藻 70 0 2培养体系中为 I=I0 exp[- (- 0 .0 2 39+0 .0 777OD750 )·L],并据此对培养过程中光强沿反应器径向的动态分布情况进行了估算。在该反应器中进行了鱼腥藻 712 0和聚球藻 70 0 2两种蓝藻的光自养培养 ,藻细胞培养终密度分别达到 1.5 3g/ L和 3.4g/ L ,体积产率分别为 0 .31g L-1d-1和 0 .5 7g L-1d-1,说明该反应器适合于微藻的高密度培养     

蛋白核小球藻的光衰减模型及藻细胞受光特性参数的模拟

采用不同的光衰减模型对浓度0.06~2.68 g/L的蛋白核小球藻藻液中光的衰减特性进行对比. 结果表明,Cornet模型能较好地描述和预测藻液中光的衰减特性,光吸收系数Ea和光散射系数Es分别为0.0014和0.9022 m2/g;随藻细胞中色素含量增加,Lambert-Beer模型中的消光系数Ka和Es增大,而Ea减小. 与高藻细胞浓度相比,低藻细胞浓度时藻细胞中色素含量对藻液中光衰减程度影响更显著. 结合计算流体力学和Cornet光衰减模型计算了平板式光生物反应器中藻细胞受光特性参数,在相同的外部条件下,与3 L平板式光生物反应器相比,15 L平板式光生物反应器中的藻细胞时均光强平均下降35.5%,藻细胞光暗循环周期平均增加78.1%.     

普通小球藻异养-光自养串联培养的培养基

采用单因素实验和均匀实验获得了适合于普通小球藻异养-光自养串联培养的培养基(HA-SK培养基),其关键是C/N比和保证足够的C, N供应. 采用该培养基在摇瓶中异养-光自养串联培养普通小球藻,异养培养结束时细胞密度达13.17 g/L,经过36 h光自养培养后藻体蛋白质和叶绿素含量分别达49.75%和30.17 mg/g. 用5 L生物反应器和1 L平板光生物反应器串联培养,藻细胞密度最高可达15.36 g/L,藻体蛋白质和叶绿素含量分别达54.78%和31.23 mg/g. 表明采用HA-SK培养基进行异养-光自养串联培养可实现普通小球藻的高密度高品质培养.     

套管式新型光生物反应器的性能初步实验

针对管式光生物反应器藻液中溶解氧及pH限制进一步规模扩大等因素,设计了一种套管新型内曝气式光生物反应器。以Chlorella vulgaris为培养对象,BG-11为培养基,以细胞干重为检测指标,同时检测藻液的溶氧量和pH,比较了小规模实验条件(锥形瓶,500 mL)和套管式新型光生物反应器(36 L)对微藻生物质积累的影响。结果表明,新型反应器和小规模实验条件相比,培养体积扩大了72倍,培养10 d时微藻的比生长率下降了33.2%,单位体积产率下降了69.8%。在整个培养过程中,藻液溶氧量为6.2～7.0 mg/L,未超过限值7.5 mg/L。通入气体为空气,藻液pH由7.5上升至9.0,处于微藻可适应范围(4.5～10.6),尚可通过在空气中混入CO2进行调节。     

气升式微藻光生物反应器的设计研究进展

概述了几种常见密闭式光生物反应器的发展现状,着重讨论了近几年气升式内环流光生物反应器在光源利用率与混合效果方面的研究进展,以及结构尺寸和附属装置对混合效果的影响,作为对现有气升式光生物反应器进一步研究和改进的基础。     

Simulation of algae growth in a bench scale internal loop airlift reactor

The growth of red marine alga Porphyridium sp. cultivated in an internal loop airlift (ALR) photobioreactor was simulated. The model proposed integrates a dynamic formulation of the kinetics of photosynthesis, photoinhibition, and the fluid dynamics of the ALR, including shear stress effects on the kinetics of growth. The kinetic parameters obtained previously for a system under defined light/dark cycles were used, and satisfactory agreement was found. The maintenance term was modified to take into account the detrimental effects of shear stress in the bioreactor on the rate of growth. A hybrid method for approximate solution of the equations is proposed. The conditions of gas flow rate and illuminance required for positive growth were found. This is the first mathematical model that predicts the effect of gas flow rate, column height, column diameter, and cross-sectional areas on the productivity of a photosynthetic process in an airlift bioreactor. Extrapolations done using the model indicate the possibility of predicting the optimal diameter for an assembly of ALR photobioreactors.     

光生物反应器中光强和Fe3+浓度对铜绿微囊藻生长和毒素合成的影响

在2.5 L光生物反应器中考察了光强、通气量等对铜绿微囊藻生长的影响,确定了最佳生长条件. 在此条件下考察不同Fe3+浓度(0~500 mmol/L)对铜绿微囊藻的生长、叶绿素及微囊藻毒素(MC-LR)含量的影响,同时考察光照强度对铜绿微囊藻产毒素的影响. 实验结果表明,在低铁(Fe3+<0.1 mmol/L)、缺铁(Fe3+<0.01 mmol/L)及高铁(Fe3+>100 mmol/L)环境下,微囊藻生长、叶绿素及毒素合成均受到抑制. 生物量和叶绿素在Fe3+浓度为100 mmol/L时含量最高,毒素在Fe3+浓度为10 mmol/L、光强为30 mmol/(m2×s)时含量最大.     

Optimization of Carbon Dioxide Fixation by Chlorella vulgaris Cultivated in a Membrane‐Photobioreactor

In this paper, an enclosed membrane‐photobioreactor was designed to remove CO₂ using Chlorella vulgaris. The performances of four reactors, which included the presented novel bioreactor, a draft tube airlift photobioreactor, a bubble column and a membrane contactor, were compared. The effects of the gas flow rate, light intensity, quality of the inner light source, and the characteristics of membrane module on CO₂ fixation were investigated. The results showed that the rate of CO₂ fixation in the membrane‐photobioreactor was 0.95–5.40 times higher than that in the other three conventional reactors under the optimal operating conditions     

Development of gas recycling photobioreactor system for microalgal carbon dioxide fixation

A gas recycling photobioreactor was developed to achieve high CO₂ conversion, in whichChlorella vulgaris was cultivated under various light intensities. The light intensity affected the algal growth and the CO₂ concentration in the exit gas. However, the final cell density was independent of light intensity and was limited by nitrate concentration in the medium. In the linear growth phase, the CO₂ concentration in the exit gas ranged 4.6 to 6.0 % (v/v) when 20 % (v/v) CO₂ balanced with 80 % (v/v) N₂ was introduced into the photobioreactor. The gas recycling photobioreactor developed in this work was claimed to be a useful system for microalgal CO₂ fixation.     

盐藻细胞泡载分离法采收的初步研究

通过对盐藻细胞的浓缩倍数和采收率的测定，考察了藻液pH值、气体流速(vg)、藻细胞初始浓度(C0)对盐藻细胞的泡载分离采收性能的影响，优化了盐藻细胞泡载分离采收条件. 结果表明：在vg为60 ml/min，C0为2.58?105 个/ml，pH值为7.5的条件下，盐藻细胞泡载分离的采收率达90%~94%，浓缩倍数达30~34. 泡载分离是分离浓缩盐藻细胞的一种简便、高效的方法.     

普通小球藻固定模拟烟气中CO2的实验研究

大气中CO₂浓度增加造成的全球变暖已成为一个严峻的环境问题,利用微藻生物固碳法减排CO₂正成为研究热点.本文以普通小球藻(Chlorella vulgaris,FACHB-1227)为研究对象,采用SE无碳培养基,在沿程曝气型套管式光生物反应器中通入含不同体积分数CO₂(5%、10%、15%和20%)的模拟烟气培养小球藻,培养周期为17天,以细胞密度和平均固碳速率为检测指标,研究模拟烟气下普通小球藻生长情况及固碳能力.实验结果表明:当模拟烟气中CO₂体积分数为10%时,普通小球藻的细胞密度达到最大值8.76×10⁶cells/mL,相比于5%组、15%组和20%组分别提高了54.23%、66.86%和76.97%;其平均固碳速率达最大值30.18mg/(L·d),较5%组、15%组和20%组分别提高了57.27%、70.89%和81.91%.可见,在模拟烟气中CO₂体积分数为10%时,普通小球藻的生长情况和固碳性能最好.     

High Density Culture of Porphyridium cruentum in a 42 L Internal Airlift Loop Photobioreactor

1 INTRODUCTION Porphyridium cruentum is a kind of unicellular microalgae, which can live widely in freshwater, marine, brackish, and soil environment[1]. Great attention has been paid to its potential economic value such as the high content of essential high unsaturated fatty acids, especially arachidonic acid (AA) and eicosapentaenoic acid (EPA) (ca 50% in the total fatty acids), ploysaccharides, and synthetic pigments, especially phycoerythrin (PE)[2,3]. During cultivation, the cells…     

气升式环流反应器研究与应用进展

综述了气升式反应器性能的主要影响因素研究及其最新的应用，提出今后研究工作的主攻方向，并介绍了最近超声气升式反应器及光气升式反应器的研究结果。     

A tubular bioreactor for photosynthetic production of biomass from carbon dioxide: Design and performance

A theory of photobioreactor design is developed. A photobioreactor was constructed in the form of a loop made from 52 m of glass tubing of 1 cm bore; the loop covered about 0.5 m². The culture was illuminated with mercury halide lamps to reproduce sunlight. Computer control was used to maintain constant biomass concentration. The influence of radiation on the reactor temperature is quantitatively predicted. An air lift system was preferred to a liquid pump for culture recycle. The energy required for culture recycle in the loop with Reynolds number 2000 was 0.6 W m^?2. The CO₂ gas/liquid transfer rate achieved was sufficient to meet the maximum possible demand with solar irradiation. The O₂ gas/liquid transfer rate was sufficient to meet the maximum respiration demand at night. The maximum algal biomass concentration achieved exceeded 20 g dry weight litre^?1. A biomass concentration of 8 g dry weight litre^?1 was found to be convenient for normal operation. The maximum uptake of light in the available wavelength range (400–700 nm) was 38 W m^?2, this corresponds to utilisation of solar irradiation up to 89 W m^?2. Below the maximum light uptake rate the efficiency of storage of light energy in the biomass corresponded to 16.6% of solar energy.