Eman Bellah Aly Ramadan
The American University in Cairo, Egypt
Title: Molecular adaptation of a metagenome-derived mercuric reductase from Kebrit Deep brine environment in the Red Sea to high salinity
Biography
Biography: Eman Bellah Aly Ramadan
Abstract
Red SeaKebrit Brine (1490m)possess unique environmental conditions, characterized by high salinity 4 M, temperature 23.4°C, elevated concentration of heavy metals, no oxygen and high hydrostatic pressure. In order to highlight the structural-functional relationship of enzymes adaptation to such extreme environmental conditions, DNA isolated from the microbial community of Kebrit Brine is subjected to 454-pyrosequencing and a metagenomic dataset is established; and looked for enzymes involved in mercury detoxifications. An operon containing the genes essential for mercury detoxification was identified in our 454-pyrosequencing metagenomic dataset. A total of 28merAOrthologs were identified in Kebrit Brine metagenomics library, choosing two merA genes: one representing the consensus sequence (K35-NH) and the other (K09-H) has amino acid substitutions replacing non-polar with acidic amino acids. Kinetic parameters were measured at the NaClconcentration that gave maximum activity for the respective enzyme. K09-Hmaximal activation is observed at 2Molar NaCLand retains 65% of its activity at 3 Molar. K35-NH showed maximum activity at 0 Molar NaCl which is equvlent to 52% activity of K09-H at 4 M. Both and K35-NH retained 90%of their activity after 10 minutes incubation at 65ËšC.Comparing the kinetics of both enzyme suggested, that the amino acids difference between the two orthologs are acquired evolutional structural adaptation to confer site-specific level of halophilicity to survive in such extreme environment as KebritDeep.Thishalophilic feature if used properly is a potential for many industrial and bioremediation applications in detoxification of mercury.