海洋能源微藻细胞半干贴壁培养方法的基础研究

Mass cultivation of marine oleaginous microalgae is the bottleneck of microalgae biofuel industrial application. Conventional open pond and photobioreactors could not solve the problems of biomass productivity,water and power consumption,scale-up, captial investiment and cost.This project is based on our newly proposed semi-dry attached culture method for microalgae. microalgae cells were inolcumated on a supported materials surface to form"artifical leaf", and little nutrients medium was supplied to keep algal cell wetted for fast growth and lipid induction. The mechanisms of grwoth and lipid induction under attached culture, the correlation between the growth rate with light intnensity, and the influences of envioronmental factors including nutrient composition, CO2 concentration etc. on algal cells' growth and lipid accumulation were investigated. The results will help to understand the mechanism of attached cultivition and regulation method, and then provide more information for the bioreaction design and determination of cultivation conditions. It is hoped to setup a breakthough technology for microalgae cultivation and also to promote the conventional econmic microalgae industry.

微藻的规模培养是微藻生物能源技术产业化的瓶颈。传统的开放式跑道池和各类光生物反应器的培养效率低、能耗高、用水量大、设备投资大、成本高和放大困难的问题，不能适应微藻生物能源产业化的需要。本项目提出微藻细胞半干贴壁培养的新方法，将微藻细胞种子接种在支撑材料表面形成类似"人工叶片"的藻细胞层，用极少量的培养基液体保持藻细胞半干润湿并提供营养，促使细胞高效生长并积累油脂。研究微藻细胞的贴壁生长与油脂诱导机制、贴壁培养藻细胞的光全放氧规律、微藻细胞的贴壁生长速率与光照强度关系、半干贴壁微藻细胞生长与油脂诱导的环境影响因素等。项目研究结果将为全面了解微藻贴壁培养的机理与环境（工艺）影响规律，微藻高效贴壁培养反应器结构设计、工艺参数优化奠定基础，从而实现海洋微藻生物能源规模培养瓶颈问题的重要突破。该技术方法的建立还将为现有经济微藻培养技术的产业升级提供重要技术支撑。

本项目提出微藻细胞半干贴壁培养的新方法，研究微藻细胞的贴壁生长与油脂诱导机制、贴壁培养藻细胞的光合放氧规律、微藻细胞的贴壁生长速率与光照强度关系、半干贴壁微藻细胞生长与油脂诱导的环境影响因素等。. 研究发现，贴壁培养下虽然单个细胞的生理状态并不具优势，但其藻细胞受光率可达60—100%，而悬浮培养时只有30%左右的藻细胞能够受光，从而很好的解释了贴壁培养国家整体高光效高产率的原因；基于贴壁藻细胞的补偿光强与饱和光强，提出了光强稀释的微藻贴壁培养反应器设计原理；贴壁培养微藻特别是中频（0.1Hz）闪光比持续光照生物量生产速率提高了8.9%；建立了栅藻贴壁培养实现生物量与油脂同步积累的最佳供氮策略；发现葡萄藻贴壁培养时能够吸附钴且钴对葡萄藻的长链烃有促进作用，奠定了利用含钴废水进行葡萄藻贴壁培养的原理基础；气相补碳比气相CO2先通入培养基中形成富碳培养基有利于微藻生长；进一步发展了可模拟水生和陆生培养环境和不同浓度CO2下的贴壁培养平台，从而首次建立了产油和β-类胡罗卜素橘色藻的半气生贴壁培养模式，为橘色藻贴壁培养的油脂与高值化学品联产工艺建立奠定了基础。