Novel bioprocessing strategies for optimization of aerobic fermentation bioreactor performance

由于近几十年来生物技术的重大进步，人们普遍认为生物基生产是一种现代化、创新、可再生和可持续的生产方式，具有取代石油生产的潜力。拟议的研究将针对设计/开发用于生物制造目的的精确生物系统监测和控制的新型生物工艺设施。我们小组最近开发的各种工程菌株，包括枯草芽孢杆菌和大肠杆菌，将用于生产增值化学品，包括l -缬氨酸、透明质酸（HA）、丙酸盐、聚3-羟基丁酸-co-3-羟基戊酸酯（PHBV）和病毒样颗粒（VLPs），作为潜在的基于蛋白质的COVID-19病毒候选疫苗，在传统的搅拌槽和新型波浪生物反应器中。由于相关生物合成酶的敏感性和对氧的途径不同，它们的生物基生产在生物反应器培养过程中需要不同的曝气水平。将采用传统的搅拌池和新型的波浪生物反应器对不同生物制品发酵工艺的曝气需求进行评价，并制定最佳的曝气生物工艺策略。生物产品发酵的不同曝气要求将首先根据氧敏感性和相关生物合成酶和途径的参与来确定。监测溶解氧水平的微型探针将安装在这两种生物反应器的多个地方。将一种新型的浸没式气体分散分散器安装在波浪生物反应器的摇包中，用于强化曝气。将建立这些增强设计的生物处理特性，以便对生物反应器发酵过程进行定量评估，以进行综合机制和生物建模，特别是粘性和高密度发酵。增强型生物反应器设计的曝气/搅拌能力以及结构和流变特性的数学相关性将在不同菌株和生物产品发酵条件下得到广泛应用。该研究的成功将促进生物制造的科学和工程进步，提高生物加工的经济可行性，并减轻传统化学加工对环境造成的重大影响。开发的工程策略和生物工艺可以很容易地转移到加拿大的生物产业，提高加拿大在生物制造方面的技术领先地位。此外，拟议的研究将导致改进甚至新的生物制造企业，为加拿大和其他地方带来社会经济效益。在多学科研究中同时进行的高素质人员（HQP）培训预计将导致在广泛的当前和新兴生物技术机会中就业。

Due to major biotechnological advances in recent decades, it is well recognized that bio-based production is a modern, innovative, renewable, and sustainable way with potential to replace petro-based production. The proposed research will target design/development of novel bioprocess facilities for precise biosystem monitoring and control for biomanufacturing purposes. Various engineered bacterial strains, including Bacillus subtilis and Escherichia coli, recently developed in our group will be used for the production of value-added chemicals, including L-valine, hyaluronic acid (HA), propionate, poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV), and virus-like particles (VLPs) as potential protein-based vaccine candidates against the COVID-19 virus, in both traditional stirred-tank and novel wave bioreactors. Due to different sensitivities of the relevant biosynthetic enzymes and pathways to oxygen, their bio-based production will require different levels of aeration during bioreactor cultivation. Both traditional stirred-tank and novel wave bioreactors will be used to evaluate the aeration needs and develop the optimal aeration bioprocessing strategies for various bioproduct fermentation processes. Different aeration requirements for bioproduct fermentation will be first determined based on the oxygen sensitivity and involvement of relevant biosynthetic enzymes and pathways. Micro-probes monitoring the level of dissolved oxygen will be installed in multiple places of both types of bioreactors. A novel elongated submerged gas-dispersion sparger will be fabricated and installed in the rocking bag of wave bioreactors for enhanced aeration. Bioprocessing characterization of these enhanced designs will be established to allow quantitative evaluation of bioreactor fermentation processes for integrated mechanistic and biological modeling, especially for viscous and high-cell-density fermentations. Mathematic correlations for the aeration/agitation capabilities and the structural and rheological characteristics of the enhanced bioreactor designs will be developed for extensive application under different strain and bioproduct fermentation conditions. The success of the proposed research will mediate scientific and engineering advances in biomanufacturing, enhance economic feasibility of bioprocessing, and alleviate major environmental impacts caused by traditional chemical processing. The developed engineering strategies and bioprocesses can be readily transferred to the Canadian bioindustry, boosting Canada's technological leadership in biomanufacturing. In addition, the proposed research will lead to improved and even new biomanufacturing enterprises for socioeconomic benefits to Canada and elsewhere. The concurrent highly qualified personnel (HQP) training in multidisciplinary studies is expected to lead to employment in a wide range of present and emerging biotechnology opportunities.