Kati Geszvain

Research Interests:

• Bacterial physiology
• Metal transformations by environmental bacteria

CURE-E Course: Microbial Genetics (BIOL 472), first introduced with CURE-E in Fall 2021

Project Title:Identification of genes involved in manganese oxidation and dye-decolorization in Pseudomonas putida GB-1

The metabolic activities of bacteria can both profoundly affect global geochemical cycles and be harnessed for human benefit. One such metabolic activity is manganese (Mn) oxidation. Manganese is one of the most common transition metals in the Earth’s crust; as a transition metal, it can be found in the environment in different redox states. Bacterial Mn oxidation transforms soluble, reduced Mn2+ to its insoluble, oxidized Mn4+ form, affecting the bioavailability of this essential micronutrient. The insoluble Mn4+ reacts with oxygen, producing Mn oxide minerals that are themselves strong oxidants. These biogenic Mn oxides are currently being studied for their ability to break down environmental toxins such as dyes or pharmaceutical products. Pseudomonas putida GB-1 is a model Mn-oxidizing bacterium that has been extensively used to study the physiology of Mn oxidation. In this CURE-E project, students will randomly mutagenize P. putida GB-1 cells and screen for mutations that alter its Mn oxidation ability. They will also screen for mutants that alter the ability of the bacterium to break down the dye Congo Red. Their results will expand our understanding of the physiology of Mn oxidation and possibly identify mutants with increased ability to breakdown dye.