Strain engineering and bioprocessing strategies for bio-based production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) using cheap feedstocks

由于化石燃料供应的不稳定，气候变化对环境的诸多担忧，对石油生产的严格监管，以及“低碳”经济的动机，用生物质-生物战略取代石化过程已被公认为一种可再生、可持续和清洁生产增值化学品和燃料的现代技术。聚羟基烷酸酯(PHAs)是近年来备受关注的天然聚酯，有望取代石油基合成塑料，对环境产生重大影响。基于对生物基生产PHAs的共同兴趣，我们在滑铁卢大学的生物制造研究小组和多伦多的GeneCIS BioIndustries公司发起了这项拟议的研究，主要目标是开发一个先进的全细胞转化平台，包括基因和代谢工程细菌菌株及其相关的生物处理策略，用于使用廉价的原料，如甘油和挥发性脂肪酸(VFAS)生产PHAs的生物聚合物聚(3-羟基丁酸酯-3-羟基戊酸酯)(PHBV)。GeneCIS最近在认识到与其现有的PHA生物工艺和产品相关的某些限制后，决定探索与PHBV相关的技术。开发的用于生产PHBV的工程化细菌菌株和生物工艺可以很容易地转移到GeneCIS进行大规模生产，使现有的加拿大生物聚合物行业不仅在技术上而且在经济上受益。拟议的研究在生物科学和工业生物技术方面也是高度多学科的，预期的结果和好处如下：(1)开发清洁、可再生、可持续和经济上可行的PHBV型生物工艺；(2)提高加拿大在生物加工战略和生物聚合物生产方面的研究能力和技术开发；(3)通过清洁的生物制造改善加拿大的生活环境和减少温室气体排放；以及(4)培训高素质人员(HQP)，以应对下一代工业生物技术的挑战。

Due to unstable supply of fossil fuels, numerous environmental concerns of climate change, stringent regulations for petro-based production, and motivation to "low carbon" economy, replacing petrochemical processes with biomass-biological strategies has been recognized as a modern technology for renewable, sustainable, and clean manufacturing of value-added chemicals and fuels. Polyhydroxyalkanoates (PHAs) are natural polyesters recently attracting considerable interests as promising candidates to replace petro-based synthetic plastics with numerous environmental impacts. Based on common interests in bio-based production of PHAs, our biomanufacturing research group at UWaterloo and Genecis Bioindustries, a Toronto-based company, initiate the proposed research with a major objective to develop an advanced whole-cell transformation platform, including genetically and metabolically engineered bacterial strains, and their associated bioprocessing strategies, for the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), a biocopolymer member of PHAs, using cheap feedstocks, such as glycerol and volatile fatty acids (VFAs). Genecis has recently decided to explore PHBV-related technologies upon recognizing certain limitations associated with their existing PHA bioprocess and products. The developed engineered bacterial strains and bioprocesses for PHBV production can be readily transferred to Genecis for large-scale production, benefiting the existing Canadian biopolymer industry not only technologically but also economically. The proposed research is also highly multidisciplinary in biological sciences and industrial biotechnology with the following envisioned outcomes and benefits: (1) developing a clean, renewable, sustainable, and economically feasible PHBV bioprocess; (2) boosting Canada's research capacity and technological development in bioprocessing strategies and biopolymer production; (3) improving Canada's living environment and mitigating greenhouse gas emissions through clean biomanufacturing; and (4) training highly qualified personnel (HQP) for meeting challenges of the next generation of industrial biotechnology.