Graduate Student

Department of Chemical Engineering
Massachusetts Institute of Technology
Room: 66-425
77 Massachusetts Ave.
Cambridge, MA 02139 USA

Phone: (617) 258-8037
E-mail: neidi@mit.edu

Resume

Education
B.S. Chemical Engineering
University of Puerto Rico at Mayaguez, 2005

Research Description
My work focuses on the optimization of recombinant gene dosages for metabolic engineering in Escherichia coli. In many biopharmaceutical processes the use of high copy plasmids for the production of foreign proteins in host organisms is preferred in order to maximize product yields. However, the metabolic burden imposed by the limitation of cellular resources in the host cell may reduce the productive capability of the process, particularly for small molecule production. To ensure maximum productivity, the expression level must be optimized, especially if the substrate for the final product of interest is a metabolite involved in host maintenance.

Currently, I am working with a system for the production of polyphosphates (polyP) in E.coli. PolyP molecules are produced in a one-step mechanism in which a terminal phosphate from an ATP molecule is transferred to a growing polyP chain by the action of the enzyme polyphosphate kinase (PPK). PolyP is ubiquitous in nature, but its production can be enhanced by the introduction and induction of additional copies of the ppk gene. I am studying the effects of changes in expression level by varying the gene dosage of ppk through the use of low, medium and high copy plasmids. By measuring the specific polyP content and the PPK activity, I attempt to establish a relationship between copy number and final product concentration. The ultimate goal would be to derive some fundamental relationships between gene dosage and final product that will allow the construction of optimal recombinant microorganisms.