Cellulose synthase complex configuration effects in microalgal cellulose

项目背景（问题的识别及其对可持续性的重要性和相关性）由于当前的全球食品贸易，塑料包装已成为现代基础设施中必不可少的。然而，塑料，特别是一次性塑料，正在对环境造成负面影响。在使用后，只有14%的塑料被回收利用，32%被释放到环境中。塑料不能被生物因素降解，而是缓慢分解形成微塑料，在环境中积累，对人类和其他生物造成损害。解决这一危机的一个办法是用生物塑料取代传统的塑料材料。生物塑料是由可再生资源制成的塑料，如陆地作物，农业废物或快速生长的微生物。纤维素是自然界中最丰富的生物聚合物，由许多不同的生物体合成。再生纤维素膜由于其良好的阻隔功能性、机械性能、生物降解性和可再生性而可能是食品包装的理想选择。然而，人们担心大量的纤维素可以可持续地获得，而不会占用种植粮食作物的空间或导致森林砍伐。目前的纤维素来源也有一些属性需要改进，以用于各种各样的包装材料。许多纤维素来源已被探索，但微藻是一个研究不足的领域，特别感兴趣的是，由于它的许多优点，其他形式的纤维素原料，包括纤维素结构的差异。可以产生再生纤维素膜。该过程通过从宿主物种中提取纤维素然后破坏纤维素聚合物之间的键而发生。纤维素聚合物然后可以通过凝固介质重新形成膜，凝固介质允许纤维素聚合物结合，形成膜。微藻是具有不同纤维素结构的物种，可以为提取的纤维素提供独特的特性。纤维素形成的结构取决于纤维素合酶复合物（末端复合物）的位置。在高等植物中，这些细胞排列成六边形结构，称为莲座结构。在微藻中，它们也可以排列成单行、多行或对角行。这种结构上的差异可以赋予不同的物理化学性质，这将有助于创造用于不同应用的生物塑料或用于多种目的的联合收割机。因此，对藻类纤维素的研究及其在藻类膜中的创造可以提供多种好处，并有助于解决当前的塑料危机。实验的第一阶段将是使用模式藻类小球藻（Chlorella vulgaris）来开发成功的提取和膜形成过程，该过程允许膜形成所需的有利的结构分解，同时保留一些原始纤维素结构。第二阶段将使用呈现不同纤维素合酶复合物的不同藻类来源，并比较膜的结构和性质。最后阶段将是优化提取过程，以限制环境影响和使用藻类物种的膜的特性。然后，该信息可以用于扩大生产，以用于现实世界的实践环境。

Project background (identification of the problem and its importance and relevance to sustainability)Due to the current global food trade, plastic packaging has become essential in modern infrastructure. However, plastic, particularly single use, is causing negative environmental impacts. After use, only 14% of plastic is collected for recycling, with 32% being released into the environment. Plastic cannot be degraded by biotic factors and instead breaks down slowly to form microplastics that accumulate in the environment causing damage to humans and other organisms. One answer to this crisis is to replace conventional plastic materials with bioplastics. Bioplastics are plastic made from renewable resources, such as terrestrial crops, agricultural waste, or fast-growing microorganisms. Cellulose is the most abundant biopolymer in nature and is synthesised by many different organisms. Regenerated cellulose films could be ideal for food packaging due to their good barrier functionality, mechanical properties, biodegradability, and renewability. However, there are concerns about where a large amount of cellulose could be sourced sustainably without taking up space for growing food crops or causing deforestation. There are also some attributes of current cellulose sources which will need to be improved for use in a wide variety of packaging materials.Many cellulose sources have been explored, but micro-algae is an under-researched area of particular interest due to its many advantages to other forms of cellulosic feedstock, including differentiation in cellulose structure.Proposed solution and methodologyTo utilise cellulose for food packaging, it is possible to create regenerated cellulose films. The process occurs by extracting the cellulose from the host species then breaking the bonds between the cellulose polymers. The cellulose polymers can then be reformed into a film by a coagulation medium which allows the cellulose polymers to bond, forming a film.Micro-algae are species with different cellulose structures that may provide unique properties to the extracted cellulose. The structure in which the cellulose is formed depends on the position of the cellulose synthase complexes (Terminal Complexes). In higher plants, these are arranged in a hexagonal structure called a rosette structure. In microalgae, they can also be arranged as single rows, multiple rows, or diagonal rows. This difference in structure could impart different physicochemical properties, which would help create bioplastics for varying applications or combine for multiple purposes. Research into algal cellulose and its creation into algal films could therefore provide multiple benefits and help solve the current plastic crisis. The first phase of experimentation will be to use the model algae Chlorella vulgaris to develop a successful extraction and film formation process that allows for advantageous structural breakdown necessary for film formation whilst retaining some of the original cellulose structure. The second phase will be using diverse algal sources that present the different cellulose synthase complexes and compare the structure and the properties of the films. The final stage will be to optimise both the extraction process, to limit environmental impact and the properties of the film using algal species. This information can then be used for scaling up the production for use in the real-world practice setting.