In situ electrochemical characterization of bioremediation microbial processes

我的研究项目使用原位传感器测量来表征和监测环境意义的微生物过程。微生物过程控制着地球上任何地方的环境地球化学，微生物在隔离和修复许多类型的环境污染物方面发挥着关键作用。嗜石细菌-那些使用无机代谢底物，如铁，硫，氮-是特别重要的生物修复，因为它们驱动的生物地球化学反应，可以衰减，转换，或释放污染物，如锰，砷和汞。它们的重要性使得详细和细致入微的了解如何石养微生物循环无机代谢底物的有效生物修复策略的关键。这种研究方法提供了以前无法获得的有关复杂的天然微生物群落中地球化学循环和能量转导的基本方面的信息。 电极通常用于监测环境系统中与微生物相关的地球化学参数，包括pH、氧化还原电位、电导率、溶解氧、温度和溶解离子的浓度（即，氨、硫化氢）。我最近的工作表明，除了记录实时的物理化学环境，电极记录以前无法访问的信息正在进行的动态生物地球化学过程。电极时间序列记录代谢底物运动的实时微生物介导。对这些时间序列的分形分析表明，同一地球化学反应的不同地球化学途径产生的时间序列具有特征性的不同分维。这区分了生物和非生物对正在进行的地球化学过程的贡献。 我的研究计划的短期目标是表征生物修复感兴趣的石养代谢途径，包括Fe-和As-氧化（酸性矿山排水），Mn-氧化（弗雷德里克顿市饮用水），和蓝藻（光合）毒素生产（微囊藻毒素和anatoxin在地表水体）。这将通过基于实验室的微观实验来实现。长期目标是在研究单个途径的基础上，将这些方法应用于自然（原始和污染）微生物群落。同时在原位区分和测量生物地球化学反应的能力是对现有努力的重大创新，以开发低成本的基于传感器的环境监测策略，以及扩展完善的生物电修复方法，以收集更多关于生物修复微生物群落功能的信息。使用传感器来获得特定过程的生物地球化学信息，减少了对现场人员监测的需要，并提供了更好的空间和时间分辨数据，以约束生物地球化学过程。

My research program uses in situ sensor measurements to characterize and monitor microbial processes of environmental significance. Microbial processes control environmental geochemistry everywhere on Earth, and microbes perform critical functions in sequestering and remediating many types of environmental contaminants. Lithotrophic bacteria-those that use inorganic metabolic substrates such as Fe, S, and N-are particularly important in bioremediation, because they drive biogeochemical reactions that can attenuate, transform, or release contaminants such as Mn, As, and Hg. Their importance makes detailed and nuanced understanding of how lithotrophic microbes cycle inorganic metabolic substrates critical to effective bioremediation strategies. This research approach provides previously inaccessible information about the fundamental aspects of geochemical cycling and energy transduction in complex natural microbial communities. Electrodes are often used to monitor microbially-relevant geochemical parameters in environmental systems, including pH, oxidation-reduction potential, conductivity, dissolved oxygen, temperature, and concentrations of dissolved ions (i.e., ammonia, hydrogen sulfide). My recent work indicates that, in addition to recording the real-time physicochemical environment, electrodes record previously inaccessible information about ongoing dynamic biogeochemical processes. Electrode time series record real-time microbial mediation of the motion of metabolic substrates. Fractal analysis of these time series shows that time series arising from different geochemical pathways of the same biogeochemical reaction have characteristic, different fractal dimensions. This distinguishes biological and abiotic contributions to ongoing biogeochemical processes. The short-term goals of my research program are to characterize lithotrophic metabolic pathways of bioremediation interest, including Fe- and As-oxidation (acid mine drainage), Mn-oxidation (Fredericton municipal drinking water), and cyanobacterial (photosynthetic) toxin production (microcystin and anatoxin in surface water bodies). This will be accomplished with lab-based microcosm experiments. The long-term goal, building on the study of individual pathways, is the application of these methods to natural (pristine and contaminated) microbial communities. The capability to distinguish and measure biogeochemical reactions simultaneously in situ represents a major innovation on existing efforts to develop low-cost sensor-based environmental monitoring strategies, as well as extending well-established bioelectrical remediation methods to collect more information about the functions of bioremediation microbial communities. Using sensors to obtain process-specific biogeochemical information reduces the need for in-person monitoring of sites, as well as providing better spatially and temporally resolved data to constrain biogeochemical processes.