Elucidating the xylose metabolism pathway in thraustochytrids for the conversion of hemicellulosic waste into omega-3 fatty acids and biofuel.

加拿大广阔的森林和发达的林业工业使其处于独特的地位，可以利用锯木厂残渣中的木质生物质作为生产增值产品的原料。在与普通酒精发酵类似的过程中，利用专门的微生物提供了将纸浆转化为各种消费和工业化学品的机会。然而，构成这种生物量大部分的木糖或“木”糖不易被大多数常见微生物消化。一种能够自然利用木糖的微生物是thraustochytrids——一种以死去的植物为食的海洋原生生物。此外，这群微生物还能够产生大量具有重要营养价值的脂质，使它们成为工业开发的理想目标。玛拉可再生能源公司是一家位于加拿大大西洋沿岸的藻类生物产品生产商，目前该公司在其商业化生产的欧米伽-3脂肪酸中使用thraustochytrids。然而，在商业规模上使用木质生物质作为主要原料存在重大挑战——天然木糖消耗相对缓慢，木糖只有在其他糖耗尽后才会被消耗。通过拟议的项目，Mara Renewables寻求更好地了解thraustochytrids中的木糖代谢，以设计能够在工业相关规模上以木糖生长的细胞系。这项拟议的研究将利用核磁共振来了解细胞如何分解木糖以及产生什么副产物。然后，这些信息将与遗传数据结合起来，形成一个能够预测特定基因工程策略效果的数学模型。目标是开发一种基因工程策略，将导致快速细胞生长和高脂质产量。其结果将是能够利用纸浆和造纸等工业过程产生的常见废物流，以可持续和具有成本效益的方式生产有价值的消费品。

Canada's vast forests and developed forestry industry place it in a unique position to take advantage of woody biomass from sawmill residue as a feedstock for the production of value-added products. In a similar process to common alcoholic fermentation, the use of specialized microorganisms offers the opportunity to convert pulp into a wide range of consumer and industrial chemicals. However, the xylose or "wood" sugar that makes up a large fraction of this biomass is not readily digestible by most common microorganisms. One group of microorganisms that are capable of naturally utilizing xylose is the thraustochytrids -- marine protists that feed on dead plant matter. Furthermore, this group of microorganisms are also capable of producing large quantities of nutritionally important lipids, making them an ideal target for industrial exploitation. Mara Renewables Corporation is an Atlantic Canadian producer of algal-based bio-products that is currently using thraustochytrids in their commercial production of omega-3 fatty acids. However, there are significant challenges to using woody biomass as a primary feedstock at commercial scales -- natural xylose consumption is relatively slow and xylose is only consumed once other sugars have been exhausted. Through the proposed project, Mara Renewables seeks to better understand xylose metabolism in thraustochytrids to engineer a cell line capable of growing on xylose at industrially relevant scales. The proposed study will make use of nuclear magnetic resonance to understand how the cell breaks down xylose and what byproducts are produced. This information will then be combined with genetic data to develop a mathematical model capable of predicting the effect of specific genetic engineering strategies. The goal is to develop a genetic engineering strategy that will result in rapid cell growth and high lipid yield. The result will be to enable the exploitation of common waste stream from industrial processes such as pulp and paper manufacturing to produce valuable consumer goods in a sustainable and cost-effective manner.