Microbially-Active Functional Material Based Bioreactors for Continuous Production of Biofuels and Industrial Feedstock

1159772Chidambaram拟议研究的更广泛的科学影响涉及开发一种提高生物燃料生产效率的技术。生物产生的能源和化学原料在利用可持续资源来满足我们的能源和工业需求方面具有巨大的潜力，同时将对环境的影响降至最低。由于操作和控制方便，目前大多数工业过程使用间歇式生物反应器。开发一种成本效益高、反应动力学快、效率高、生产率高的连续流动固定化微生物生物反应器是一种尚未得到满足的需求。稳定的连续流动生物反应器具有接近恒定的细胞密度，不需要频繁接种和启动，并允许持续产生感兴趣的代谢物，如生物乙醇。在追求这一目标的过程中需要克服的最复杂的问题是开发一种固定化材料，该材料既能保持固定化微生物细胞的活力，又不会阻碍微生物的代谢途径。在这方面，PI开发了一种新的美国专利申请中的固定化方法来形成MAF材料，在这种材料中，细胞活力和代谢途径都得到了保护。MAF材料是纤维中含有微生物的薄聚合物纤维支架，通过静电纺丝过程形成。这些细小的聚合物纤维具有较高的营养物质和代谢物扩散速度，从而使微生物得以生存。此外，纤维以完全随机的方式相互重叠，产生了一种开孔结构，这是流动反应器中使用的理想结构。该提案旨在设计、开发、表征和评估以MAF材料为关键部件的IMBR。在IMBR中使用MAF材料将是变革性的。除了设计和开发基于MAF材料的实验室规模的IMBR外，本研究的主要目标是：(I)评估和比较基于MAF材料的间歇发酵罐和IMBR的效率，(Ii)确定IMBR中微生物的寿命和稳定性，以及(Iii)优化MAF材料的特性，如孔隙率、纤维直径和IMBR流量，以提高IMBR的效率。一种在聚合纤维工业中广泛使用的工艺，因此使其易于扩展以用于大规模商业用途。

1159772ChidambaramThe broader scientific impacts of the proposed research involve developing a technology to increase the efficiency in biofuel production. Biologically generated energy and chemical feedstock hold immense potential in using sustainable resources to meet both our energy, as well as industrial needs, while minimizing environmental impacts. Most industrial processes currently use batch bioreactors due to ease of operation and control. There is an unmet need to develop a cost-effective continuous-flow, immobilized microbial bioreactor that has faster reaction kinetics, high efficiency and productivity. Stable continuous-flow bioreactors that have near constant cell densities do not require frequent inoculation and startup, and allows for consistent production of metabolites of interest, such as bioethanol. The most complex issue to be overcome in the pursuit of this goal, which is also the one issue that was not overcome in previous attempts, is to develop an immobilization material that maintains the viability of the immobilized microbial cells without hindering the metabolic pathways of the microbe. To this extent, the PI has developed a novel US Patent Pending immobilization process to form MAF materials in which both cell viability and metabolic pathways are preserved. MAF materials are thin polymeric fibrous scaffold containing microorganisms within the fibers and are formed via the process of electrospinning. These thin polymeric fibers have high rates of diffusion of nutrients and metabolites to allow microbial survival. Further, the fibers overlap each other in a completely random manner, giving rise to an open pore structure that is ideal for use in a flow reactor. This proposal aims to design, develop, characterize, and evaluate an IMBR in which the MAF material forms the key component. The use of MAF materials in an IMBR will be transformational. The central hypothesis is that such a system will be more efficient and have high productivity.The principal objectives of the proposed research, in addition to the design and development of MAF materials based laboratory-scale IMBRs, are to: (i) evaluate and compare the efficiencies of the MAF material-based batch fermentors and IMBRs, (ii) determine the longevity and stability of microbes in the IMBRs, and (iii) optimize the MAF material characteristics such as porosity, fiber diameter, and IMBR flow rate, to increase efficiency of IMBRs.The PI has recently developed the MAF materials via the process of electrospinning; a process that is widely used in the polymeric fiber industry and therefore makes it readily scalable for large-scale commercial use.