Harnessing biodegradable plastics from microalgae cultivated on recalcitrant waste streams

全球每年生产约3亿吨塑料。这些塑料中只有一小部分被回收，更多的塑料最终成为废物。垃圾填埋场、水资源、湖泊、河流和海洋中的塑料是一个严重且日益严重的问题。特别令人关切的是微塑料（直径小于5毫米的塑料颗粒），它们可被海洋生物摄入，危及其生命，并导致各种下游环境问题。 在加拿大，大约有1500亿升未经处理或处理不足的废水被引入加拿大水道。 废水排放到环境中是有害藻华（HAB）的主要原因之一，这可能对人类，鱼类和水道产生有毒影响，每年造成数亿美元的经济损失。* 这项战略赠款的总体目标是制定新的战略，从废水流中培养的微藻中收获可生物降解的塑料，从而同时解决两个严重的环境问题。具体而言，在本研究中，（a）我们研究了从藻类生产生物复合塑料（其在来自奶牛场的流出物上培养）;（B）我们研究了单体衣康酸在基于微藻的表达系统中的表达;以及（3）我们评估了新方法的发展，这些新方法使用从农场污水流中生长的转基因藻类中产生的衣康酸来制备新的生物降解聚合物。我们在这个研究项目中与当地一个大型奶牛场密切合作，利用好氧和厌氧消化池的废水作为微藻生物塑料的基质。利用重组微藻收获藻类纤维复合材料和衣康酸并最终在传统塑料中生产可生物降解的片段的研究将导致经济上具有竞争力的生物产品，这将有利于社会，环境和经济。拟议的研究将带来发展农村经济的新机会，并培养这些领域的高素质人才。

Approximately 300 million tons of plastics are produced annually on a global scale. Only a fraction of these plastics are recycled and a much larger amount ends up as waste. Plastics in landfills, in water resources, lakes, rivers, and oceans are a serious and growing issue. Of particular concern are micro-plastics (particles of plastic less than 5 mm in diameter), which can be ingested by marine organisms, endangering their life and leading to various downstream environmental problems. In Canada, around 150 billion litres of untreated or under-treated wastewater are introduced into Canadian waterways. The discharge of wastewater into the environment is one of the major causes of harmful algal blooms (HABs), which can have toxic effects on humans, fish, and waterways and economic losses in hundreds of millions of dollars annually. ****The overall objectives of this strategic grant are to develop new strategies for harvesting biodegradable plastics from microalgae cultivated on wastewater streams, thus, addressing two serious environmental issues simultaneously. Specifically, in this research, (a) we investigate the production of bio-composite plastics from algae ( which are cultured on effluents from a dairy farm); (b) we investigate the expression of the monomer itaconic acid in microalgal-based expression systems; and (3) we evaluate the development of new approaches to use itaconic acid produced from genetically modifed algae grown on farm effluent streams for the preparation of new biodegradable polymers. We work closely in this research project with a large, local dairy farm, utilizing effluent streams from aerobic and anaerobic digesters as substrates for microalgal bioplastics. The research using recombinant microalgae to harvest algal-fiber composites and itaconic acid and ultimately produce biodegradable segments in conventional plastics will lead to economically competitive bio-products which will benefit society, the environment and the economy. The proposed research will lead to new opportunities to develop the rural economy and also train highly qualified personnel in these fields.************