信号标签诱变技术.pptVIP

Mechanisms of U(VI) Reduction and Sediment Growth in Desulfovibrio Lee Krumholz Department of Botany and Microbiology Goals Identify mechanisms of survival of sediment bacteria in U(VI) contaminated sediments. This was further refined to Identification of mechanisms of dealing with U(VI) Identification of mechanisms of survival in Anoxic sediments. Desulfovibrio G20 Mechanisms of U(VI) reduction Identification of Genes involved in U(VI) Response 10 mutants Potential Functions of mutated genes in U(VI) Sensitive Mutants DNA repair rRNA methylation Protein Renaturation Washed Cell U(VI) reduction test by 24 mutants The Region surrounding the mutation in B11E9 Mechanism of As(VI) Reduction Loss of As(V) Tolerance. B11E9 also lost As(V) resistance when grown in lactate sulfate media with 20mM As(V) Growth and U(VI) reduction of G20 with Cd Mechanism of U(VI) Reduction U(VI) Reduction by E. coli transformant Signature Tagged Mutagenesis First developed to identify virulence genes in pathogens. Use the technique to identify functions involved in sediment growth. Different from functions needed for lab growth. Response to mutagens One mutant B12(pF11) belongs to UmuC family. It has 53.83% similarity to D. vulgaris umuC protein. What have we learned from STM Identified a number of genes and cell functions that are required for life in the real world but not needed for growth in culture. Demonstrated for the first time the importance of specific genes as cells are growing in natural environments. Raised many questions regarding function of specific genes. Regulatory genes. Protection from toxins. DNA repair, etc. Acknowledgments Funding from DOE ERSP program. Qingwei Luo, Jennifer Groh, Xiangkai Li and Nydia Castaneda. EMSL * Isolated from an oil producing reservoir. 4.1 Mb, 3598 candidate genes Doubling time is ~4.6 hours Growth Experiment with B11E9 D. vulgaris Overview of signature tagged mutagenesis (STM