Investigating the Manganese Oxidase Enzymatic Activity in Novel Archaea from Yellowstone National Park
Manganese(III) and manganese(IV) oxides are the second strongest oxidizing agents in nature and play an important role in bioremediation processes by reacting with the reduced form of other metals, significantly influencing the solubility of toxic metals in the environment. Previously, multicopper oxidases (MCOs) and manganese oxidizing peroxidase (MopA) from bacteria, were the only identified enzymes capable of oxidizing manganese(II) to the higher oxidation states of Mn(III) and Mn(IV). It is understood that oxygen is essential to this process, with no anoxic formation of particulate Mn being demonstrated. However, based on preliminary DNA sequencing of archaea enrichment cultures from biofilms obtained from a Mn-depositing hot spring (102 ℃) in Yellowstone National Park, there is evidence that suggests there could be hyperthermophilic Mn-oxidizing archaea enzymes that exist without oxygen. Through careful sequence and structural analysis, proteins were selected for purification, which will be cloned and ligated for expression in E. coli. These will be isolated and tested for Mn oxidizing activity by replicating the host environment of these novel archaea and subjecting them to common enzyme assay conditions. In this project we aimed to develop this assay to determine the rate of Mn oxidation with the use of leucoberbelin blue (LBB). The results of these preliminary assay conditions will be presented. We aim to characterize this novel archaea in hopes of furthering our understanding of the enzymatic activity of archaeal species and discovering a Mn oxidizing enzyme capable of removing harmful Mn(III) from contaminated water sources.