Collaborative Research: EAGER: Genomic insights into microbial mat diveristy and Proterozoic geobiology

Cyanobacterial mats were critical in the evolution of Earth?s chemistry and biology. They have long been recognized as drivers of the ?great oxidation event? (GOE), and may have also perpetuated a prolonged period of intermediate redox state in the early Earth's time period call the Proterozoic. However, the types of cyanobacteria that could have mediated such geochemical transitions are poorly understood because whereas Proterozoic oceans were characterized by low oxygen, stratified and/or fluctuating redox conditions, oxygen is required by most modern cyanobacteria studied to date. Further, traditional tools used for study of microbial mats provide limited information regarding metabolic or physiological diversity of cyanobacteria. In this proposal, the PIs propose an exploratory project that will combine cutting-edge single-cell and community genome sequencing technologies with elemental and isotopic geochemistry to address questions focused on facultatively oxygenic/anoxygenic cyanobacteria dominating modern microbial mats that are excellent analogs of Proterozoic mat ecosystems. This EAGER proposal is motivated by two recent, disparate developments that together provide unique opportunities to investigate metabolically versatile cyanobacteria: (i) discovery of an easily accessible modern mat ecosystem in northern Lake Huron that is a novel analog of Proterozoic geochemistry and biology, and (ii) the advent of new genome sequencing technologies that enable unprecedented insights into uncultivated single cells as well as whole microbial communities. Broader Impacts: Undergraduate students will conduct the primary research focused on physiology (GVSU) and geochemistry (UM) and a PhD student will lead the genomics effort (UM). The discovery-driven and exploratory nature of this project provides outstanding opportunities for translating research into educational opportunities and public outreach. The PIs will take advantage of video resources (underwater dive footage, microscopic cell separations), time-lapse photography of motility, and recent coverage on the Discovery Channel (http://watch.discoverychannel.ca/daily-planet/september-2009/daily-planet-september-22-2009/#clip216315) and local news stations to develop multi-media materials (?microbes in motion? and ?laser roundup? movies). These will be integrated into outreach activities at UM and GVSU, and geobiology exhibits at TBNMS?s Visitor Center.