Using flow cytometry and genomics to characterise and optimise microalgal-bacterial consortia cultivated on Wastewater to produce biomass for Biofuel

目前，利用微藻生产生物燃料在商业上是被禁止的。这部分是由于维持光合作用所需的氮和磷养分的高经济成本。这些无机营养物在工业废水中含量丰富。培养微藻的用水要求也存在问题。为了利用海水，海洋微藻需要靠近海岸，而淡水微藻系统依赖于大量和持续的淡水供应，从耕地农业中转移了供应。因此，利用废水培养的微藻生产生物燃料具有明显的环境和经济优势。在任何大规模的微藻培养系统中，特别是当使用废水时，一个财团将由单一或几种藻类以及固有细菌组成；这些相关的细菌已被证明可以促进脂质产生。要理解这样一个复杂而动态的系统，有许多挑战。例如，系统中的相互作用将包括个体物种内部和物种之间发生的代谢变化。最终，适合用作生物燃料的生物量的数量和质量将直接与群落的生长和组成相关，而这将取决于群落内部的相互作用。目前，我们对微藻群落的组成、发育、功能和相互作用的了解甚少。该项目将使这三个中心对开发在工业用水上培育的微藻-细菌联合体生产生物燃料产生新的认识。Bharathidasan大学（BDU）在生物能源产品的分子技术和微藻培养方面拥有专业知识。光谱环境研究中心（PERC）拥有强大的藻类联盟和与工业合作处理废水的专业知识。普利茅斯海洋实验室（PML）在生物学和化学方面拥有专业知识，以了解微生物群落结构和微生物动力学。BDU和PERC将专注于在工业相关条件下优化菌株，并将结果与PML的结果结合在一起，后者将专注于了解受控合成废水实验中的微生物动力学。该项目将进行群落组成分析，以了解微藻群落在细胞和分子水平上的变化和功能。我们将测试细菌和额外的有机碳对作为生物燃料原料的藻类生物量的生长和组成的影响。我们将分别评估藻类的脂质和碳水化合物含量在生物柴油和生物乙醇中的潜力。简单地说，我们会衡量“谁在那里？”（群落/分类分析），‘它们如何比较？（比较分析）和“他们在做什么？”（功能分析），在不同条件下优化适合转化为生物燃料的生物量的数量和类型。为了做到这一点，我们将使用新颖而强大的流式细胞术工具组合来分离藻类和细菌种群，并使用基因组工具来表征群落。虽然这些工具最近被应用于研究海洋微生物生态系统，但它们还没有在很大程度上应用于了解废水微藻-细菌联合体。所获得的知识将有可能优化联合体，以提高生长速度和脂质和/或碳水化合物的数量。这可以通过控制或添加细菌、添加废碳源或通过操纵代谢途径来实现。这项研究将有助于创造解决方案，从废水中生长的微藻生产生物燃料，同时考虑到环境和经济。

Currently producing biofuel from microalgae is commercially prohibited. This is partly due to the high economic costs associated with the nitrogen and phosphorus nutrients required to sustain photosynthetic production. These inorganic nutrients can be found in abundance in industrial wastewater. There are also issues with the requirement of water for cultivating microalgae. Marine microalgae need to be situated near to the coast for utilisation of seawater and freshwater microalgae systems are dependent on large and continuous freshwater supplies, diverting supply away from arable farming etc. Therefore, producing biofuel from microalgae cultivated onwastewater has clear environmental and economic advantages. In any large scale microalgal cultivation system, and particularly when using wastewater, a consortia will be present consisting of a single or several species of algae together with a complement of inherent bacteria; these associated bacteria have been shown to boost lipid production. There are many challenges associated with understanding such a complex and dynamic system. For example, interactions in the system will include metabolic changes occurring both within individual species and between the species. Ultimately the quantity and quality of the biomass suitable for biofuel will be related directly with the growth and the composition of the consortia which will dependent on interactions within it. Currently we have a poor understanding on the composition, development, function and interactions occurring with microalgae consortia.This project will bring the three centres to develop new understanding on developing microalga-bacterial consortia cultivated on industrial water to produce biomass for biofuel. Bharathidasan University (BDU) has expertise on molecular techniques and cultivation of microalgae for bioenergy products. Phycospectrum Environmental Research Centre (PERC) has expertise on robust algal consortia and working with industry on wastewater treatment. Plymouth Marine Laboratory (PML) has expertise on the biology and chemistry to understand microbial community structure and on microbial dynamics. BDU and PERC will focus on optimising strains under industrially relevant conditions and results will be brought together with those from PML who will focus on understanding the microbial dynamics in controlled synthetic wastewater experiments. The project will undertake community composition analysis to obtain understanding on how microalgal consortia change and function at both the cellular and molecular level. We will test the effect that both bacteria and addtional organic carbon have on influencing the growth and composition of the algal biomass as a biofuel feedstock. We will assess both the lipid and carbohydrate content of the algae for potential in biodiesel and bioethanol respectively. Put simplistically we will measure 'who is there? (community/taxonomic analysis), 'how do they compare? (comparative analysis)' and 'what are they doing? (functional analysis)' under the different conditions to optimise the amount and type of biomass suitable for conversion into biofuel.To do this we will use the novel and powerful combination of flow cytometry tools to separate both algal and bacterial populations and genomic tools to characterise the communities. Whilst these tools have recently been applied to study marine microbial ecosystems, they have not been applied to any great extent to understanding wastewater microalgal-bacterial consortia. Knowledge gained will lead to potential to optimise consortia to improve growth rates and the amounts of lipids and/or carbohydrates. This could be achieved through controlling or adding bacteria, the addition of a waste carbon source, or through manipulation of metabolic pathways. The research will contribute to creating solutions to producing biofuel from microalgae grown on wastewater with consideration to both the environment and the economy.