Interactions of Biomolecules and Bacteria with Titanium at the Mineral Microbe Frontier

该奖项由化学系环境化学科学项目资助。天普大学的安·M·瓦伦丁教授被支持探索氧化钛表面与清除金属的生物分子和/或微生物的相互作用。钛在环境和生物体中都非常丰富，并越来越多地用于消费品和工业应用。钛没有被广泛认为是一种生物活性元素，因为它有极端惰性和在水中不溶的名声。这项研究考察了二氧化钛附着(附着)和从具有良好特性的生物分子和细菌中释放的能力。清除铁的生物分子将钛结合得特别紧密，并使其保持可溶和稳定。它们还会导致大量钛离子释放到溶液中。这项研究揭示了微生物对钛环境化学的影响，并揭示了钛的生物作用。这项研究与一项新的针对高三学生的外展计划相结合，该计划名为费城环境化学探索(PECA)。环境生物无机化学作为扩大科学参与度的平台。该项目的重点是铁清除铁载体和细菌与二氧化钛(二氧化钛)表面的相互作用。这项研究是无机和生物无机化学、生物地球化学、材料和环境化学的交叉学科。铁载体与二氧化钛结合强烈，一些铁载体从金属氧化物表面溶解钛离子，在此过程中显著重塑了矿物。电子光谱、元素分析和质谱分析揭示了溶液中金属离子的浓度和形态。利用衰减全反射傅里叶变换红外光谱(ATR-FTIR)以及显微技术和相关技术对氧化物的表面和溶解前、中、后的性质进行了研究。钛和铁的相互干扰是一个特别的焦点。微生物/氧化物和生物分子/氧化物的相互作用正在使用红色红球菌GIN-1细菌进行研究，该细菌附着在二氧化钛上，并将大量钛结合到其生物量中。二氧化钛表面结合蛋白正在被鉴定和表征。它们的丰度和性质与整个有机体现象相关。正在对钛的摄取进行量化，并分离细胞内的钛结合分子。在无机化学和生物化学的界面上教育和培训本科生和研究生的研究计划被维持。研究活动与化学推广相结合，并与针对高三学生的新计划相结合。该计划以环境生物无机化学为平台，扩大对科学的参与。

This award is funded by the Environmental Chemical Sciences Program in the Division of Chemistry. Professor Ann M. Valentine of Temple University is supported to explore the interaction of titanium oxide surfaces with metal-scavenging biomolecules and/or microorganisms. Titanium is very abundant both in the environment and in organisms, and increasingly used in consumer products and industrial applications. Titanium is not widely appreciated as a bioactive element as it has a reputation for extreme inertness and insolubility in water. This research examines the ability of titanium dioxide to stick to (adhere) and release from well-characterized biomolecules and from a bacterium. Iron-scavenging biomolecules bind titanium especially tightly and keep it soluble and stable. They can also cause the release of large quantities of titanium ions into solution. This research sheds light on the impact of microorganisms on the environmental chemistry of titanium and reveals the biological role of titanium. The research is integrated with a new outreach program for rising high school juniors called Philadelphia Environmental Chemistry Explorations (PECE). Environmental bioinorganic chemistry is used as a platform to broaden participation in science. This project focuses on the interactions of iron-scavenging siderophores and bacteria with titanium dioxide (TiO2) surfaces. This inquiry sits at the intersection of inorganic and bioinorganic chemistry, biogeochemistry, and materials and environmental chemistry. Siderophores bind strongly to TiO2, and some siderophores dissolve titanium ions from the metal oxide surface, significantly remodeling the mineral in the process. Electronic spectroscopy, elemental analysis, and mass spectrometry reveal metal ion concentrations and speciation in solution. The oxide surface and properties before, during, and after dissolution are being probed using Attenuated Total Reflectance-Fourier Transfer Infrared (ATR-FTIR) as well as microscopy and related techniques. The mutual interference of titanium and iron is a special focus. Microbe/oxide and biomolecule/oxide interactions are being studied using the bacterium Rhodococcus ruber GIN-1, which adheres to titanium dioxide and incorporates significant quantities of titanium into its biomass. Titanium dioxide surface binding proteins are being identified and characterized. Their abundance and properties are correlate to whole-organism phenomena. Titanium uptake is being quantified and intracellular titanium-binding molecules isolated. A research program is maintained that educates and trains undergraduates and graduate students at the interface of inorganic chemistry and biochemistry. Research activities are integrated with chemistry outreach and with a new program for rising high school juniors. This program uses environmental bioinorganic chemistry as a platform to broaden participation in science.