Grant: Discovery Grants Program - Individual

The diversity of life on Earth is an irreplaceable natural heritage. The array of microbial life is enormous; however recent evidence based on 16S eDNA sequences indicates that around 99% of microbial species remain undiscovered and require culture-based purification in laboratory to be identified physiologically and taxonomically characterized. Modern science has produced a new awareness of this extraordinary diversity within a surprising range of habitats where microbes flourish. Their metabolic types are equally broad and include a rich variety of photosynthetic and non-photosynthetic (heterotrophic) pathways. Photosynthesis is a major process that contributes and increases the free energy on Earth, and research in this field has great fundamental and applied importance. The proposed program will help us not only better understand the aerobic anoxygenic phototrophic phenomenon, but also enhance our knowledge of the light-dependent metabolism of diverse bacteria and the evolution of photosynthesis in general. Investigation of heavy metal(loid) transformations will bring in-depth exploration of novel communities and species adaptations. Of particular interest is the metal(loid) oxide reducing capacity of deep-oceanic hydrothermal vent isolates. The ability to reduce toxic oxyanions of Te to the less toxic elemental form has a great potential for bioremediation of polluted effluents from industrial operations. In addition, such bacteria could prove useful in practical biometallurgy of rare and expensive Te. The most recent surprise that came from aerobic anoxygenic phototrophs is our discovery of very important physiological feature of their cells to produce metal(loid) chelating agents. The 20 species from 14 genera tested synthesized highly effective iron chelators (siderophores) and other meal(loid) chelating molecules acting on Zn, V, Te, Cu, Mn, Mg, Se, Ni, and Co. Our proposal opens a gate to a new direction of study in important metal transforming capabilities that can be considered for bioremediation and other metal related technologies. Hence, our work will make both fundamental and technological contributions. The particular objectives of the proposed program comprise four related parts: 1. To look into diversity, taxonomic nuances and evolution of aerobic anoxygenic phototrophs; 2. To decipher mysterious aerobic anoxygenic photosynthetic apparatus; 3. To continue investigating microbial biotransformation of metal(loid)s; and 4. To continuously study the deep ocean microbiology in the vicinity of hydrothermal vents. The approaches to be taken include the use of a variety of modern and classic microbiological, biochemical, molecular biological, taxonomic and phylogenetic techniques.