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题名	微藻生物膜培养水足迹和节水策略的研究
作者	殷淑超
学位类别	硕士
答辩日期	2015-06
授予单位	中国科学院研究生院
授予地点	北京
导师	刘天中
关键词	节水式生物膜反应器 水足迹 雨生红球藻 栅藻
学位专业	生物化工
中文摘要	目前微藻在解决生物柴油的生产、CO2的生物减排问题以及高附加值产品的生产上受到越来越多的关注，并且已经产生了很多微藻培养体系。很多关于生物膜系统的研究表明它是一个长期稳定、基本无污染而且总水耗和能耗较少的培养方式。这种培养方法的水足迹究竟如何对使用此方法进行微藻大规模培养而言非常重要，但目前为止尚未有关于生物膜培养方法省水策略系统研究。本论文中，我们使用雨生红球藻和栅藻细胞进行生物膜培养。众所周知，生物膜系统在微藻培养过程中水足迹主要包括两个部分：培养基水量和蒸发量。为了减少此培养体系的水足迹，我们提出了最小化生物膜培养耗水量的策略，并设计出一种节水式生物膜反应器，进行一系列的实验包括营养盐总量、通气策略、培养水体积最终计算其最小水足迹。根据此策略设计的反应器是节水式生物膜反应器，规格为260 mm× 210 mm×15 mm，其中培养区域表面积为200 mm×200 mm。反应器内放置16片藻膜，接种面积为160 cm2。加入高浓度培养基，封闭培养并通入高浓度CO2的混合空气，7 d后采收。首先对雨生红球藻细胞的培养过程，通过比较实验所得到的生物量产率、虾青素含量和产率以得出合适的培养策略。结果表明每个反应器内最佳营养盐总量为40 mL的10×0.1 N-BG11、最佳通气浓度为1.5%、最低通气速率为6 mL min-1、最低水体积为20 mL。经计算，仅仅1.25 L水就可满足1 m2生物膜培养表面的需水量。每生产1 kg雨生红球藻干燥藻粉和虾青素在不计算水分损失条件下，分别最低需要35 L和1440 L水。而加上因蒸发和通气带来的水分损失后，分别最低需要66 L和2700 L水。其次，在培养栅藻细胞时所获得的数据与雨生红球藻的结果有所差异。第一，营养盐总量上每反应器所需量为40 mL的5×BG11培养基内所含物质；第二，通气策略发生改变，以CO2浓度为5%的混合空气按照20 mL min-1的速率通气；第三，仅需10 mL就可满足一个反应器所需，即0.625 L水分就可满足1 m2培养面积的需水量。每生产1 kg栅藻藻粉，仅需14 L水（水足迹为53 L）。每生产1 kg 油脂和TAG所需的培养基水量分别为31 L和38 L，水足迹分别为 118 L和144 L。根据以上结果，我们提出的省水策略可以用于减少生物膜培养的水足迹。此策略可归纳为：1）反应器内培养基起到提供营养盐和运输物质的作用，同时应可能的减少水体积；2）生物膜系统被封闭在一个水分饱和的腔室中；3）此光生物反应器是以含高CO2浓度的混合空气以最低速率通气。
英文摘要	Currently microalgae has attracted lots of interest because of its potential use for biofuels and high-value products and the CO2 mitigation. Many studies on the biofilm cultivation system of microalgae show that biofilm attached cultivation has the advantages of long-term stability, almost no contamination, and lower total energy consumption compared to conventional suspended cultivation. However how about the water footprint of the method is still unknown which is important when the method is used for microalgae mass cultivation.In this research, the water footprint was investigated with the mode algal species of Haematococcus pluvialis and Scenedesmus dimorphus during biofilm attached cultivation. It is well known that the water footprint during attached cultivation consists of medium volume and evaporation loss. Aims on the reduction of water footprint, a water-saving biofilm bioreactor was constructed and a serial of experiments including determination of proper nutrient amount, aeration strategy, water volume were conducted in sequence, and finally, the water footprint of the bioreactor was estimated.The water-saving bioreactor is a 260 mm × 210 mm × 15 mm glass chamber within a culture area of 200 mm × 200 mm. Sixteen alga disks are put onto the culture area in which the total effective cultivation area is 160 cm2 per chamber. After the addition of medium, the bioreactor is sealed with aeration of CO2 enriched air. After 7 days' cultivation, the alga disks are harvested.First of all, the optimal cultivation strategy of Haematococcus pluvialis cultivation by comparing biomass productivity, astaxanthin content and productivity were investigated . Results show that the optimal nutrient amount is nutrients in 40 mL 10 × 0.1 N-BG11 medium. The optimal CO2 concentration (v/v) is 1.5% with aeration speed of 6 mL min-1. The lowest mediun volume is 20 mL which indicates 1.25 L water can satisfy the water requirement of 1m2 cultivation area. To produce 1 kg of Haematococcus biomass and astaxanthin, the water footprint could be as low as 35 L and 1440 L (without considering the evaporation loss), or 66 L and 2700 L (with the evaporation loss), respectively. Secondly, the data of Scenedesmus dimorphus are a little different from Haematococcus pluvialis's. 1) Nutrients amount is minerals of 40 mL 5 × BG11 medium.2) The bioreactor is aerated continuously with CO2 enriched air flow(air: CO2=95:5,v:v) at a speed of 20 mL min-1. 3) Just 10 mL water per chamber can maintain the growth of this microalgae, which means only 0.625 L of water is enough to support 1 m2 of biofilm cultivation surface. So in order to produce 1 kg Scenedesmus dimorphus biomass, 14 L water is consumed while total water footprint 53 L. Medium volume respectively is 31 L and 38 L to produce 1 kg lipid and TAG while the total water footprint 118 L and 144 L.As the conculsion, the following measures should be taken in order to reduce the water footprint of biofilm attached cultivation: 1) concentrated medium containing enough nutrient elements should be added and the the water volume should minimumized to the degree which assures the "matter transfer" function during a specific time of cultivation, and 2) the biofilm shouldbe sealed in order to reduce the loss of water evaporation, and 3) the areation rate should be low enough with CO2 enriched air stream.
语种	中文
学科主题	化学工程与工艺
公开日期	2016-09-01
内容类型	学位论文
源URL	[http://ir.qibebt.ac.cn/handle/337004/8106]
专题	青岛生物能源与过程研究所_微藻生物技术团队
作者单位	中国科学院青岛生物能源与过程研究所
推荐引用方式 GB/T 7714	殷淑超. 微藻生物膜培养水足迹和节水策略的研究[D]. 北京. 中国科学院研究生院. 2015.

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