Production of lipids for bioconversion to biodiesel using new sludge isolated microorganisms and employing wastewater sludge as a raw material

污水污泥的大量产生及其在环境中的安全处理是一个世界性的难题。我们研究的长期目标是利用污泥作为原料生产增值产品。由于原油供应的减少、石油价格的不稳定、减少温室气体的必要性以及政府制定措施建立运输中生物燃料的最低比例，对脂肪酸甲酯（FAMEs）作为生物柴油的需求大幅增加。因此，本研究的主要目的是开发一种以废水污泥为原料的经济生产生物柴油的工艺。事实上，我们已经分离出新的异养产油菌株，它积累的脂质高达细胞干重的60%，并在污泥中增殖。根据我们的计算，我们发现从污泥中生产生物柴油的输出/输入能量比为5.1，并大大减少了温室气体。因此，本研究项目的具体目标是：鉴定新菌株，优化产脂工艺参数（pH、C:N比、污泥固体浓度、投料策略、温度）；污泥水解促进产油菌株的生长和脂质积累；建立规模化标准，研究从发酵污泥生物质中提取油脂并将油脂转化为生物柴油。本研究的成功完成：1)将为经济的生物柴油生产提供一种新工艺；2)减少60- 70% w/w的污泥量，从而最大限度地降低处置成本；4)通过用生物柴油替代石油柴油来减少温室气体的产生。此外，这项研究非常及时，将有助于加拿大工业开发生态友好和商业可行的生物柴油，加强加拿大的环境政策。本课题将培养3名博士、1名PDF和1名研究助理。

Wastewater sludge is produced in large quantityand its safe disposal in the environment is a world wide problem. The long term goal of our research is to produce value added products using sludge as a raw material. Demand for fattyacid methyl esters (FAMEs) as biodiesel has increased significantlydue to the depleting crude oil supplies, instabilityof petroleum prices, necessityto reduce GHG and the development of government measures to establish a minimum proportion of biofuel in transport. Therefore, the principal objective of the present research is to develop an economical process for biodiesel production using wastewatersludge as raw material. In fact, we have isolated new heterotrophic oleaginous strains which accumulate lipids up to 60% of cell dryweight and proliferate in sludge. Based on our calculation we find that biodiesel production from sludge has an output/input energyratio of 5.1 and substantiallyreduced green house gases. Therefore, the specific objectives of the present research project are: identification of new strains, optimize the process parameters for lipid production (pH, C:N ratio, sludge solids concentration, feeding strategy, temperature); sludge hydrolysis to increase growth & lipids accumulation byoleaginous strains; to establish scale-up criteria and to studythe extraction of lipids from fermented sludge biomass and conversion of lipids tobiodiesel. The successful completion of the research: 1) will provide a new process for economical biodiesel production; 2) reduce the sludge volume by60-70 % w/w for disposal and hence minimize disposal cost; and 4) minimize production of green house gases through replacement of petroleum diesel bybiodiesel. Furthermore, this research is verytimelyand will aid Canadian industryto develop eco-friendlyand commerciallyviable biodiesel strengthening Canada`s environmental policy. 3 PhD, 1 PDF and a research assistant will be trained on this new subject.