ASU Engineering | Nielsen Lab




Working at the interface of metabolic engineering and synthetic biology, while also applying key elements of applied microbiology and bioprocess engineering, our lab focuses on engineering novel biotechnologies for the microbial conversion of renewable feedstocks to useful biofuels and biochemicals. Our research, which integrates both fundamental and applied studies, is comprised of several key thrust areas, including: 1) pathway engineering to develop ‘cell factories’ capable of synthesizing novel and non-natural bioproducts, 2) developing generalizable strategies for carbon and energy conservation to enhance product titers and yields, 3) engineering robust microbes with industrially-relevant phenotypes (e.g., product tolerance, complex substrate utilization), 4) tools development and metabolic engineering of photosynthetic cyanobacteria, 5) engineering and fundamental investigation of synthetic microbial consortia, 6) investigating and engineering small molecule transporters associated with nutrient uptake and product efflux, and 7) developing integrated bioreactor and/or downstream bioprocessing strategies to support economical biochemical production. Through these efforts we seek to overcome key technological barriers that currently limit the potential of bio-derived fuels and chemicals.

Engineering ‘Cell Factories’

By applying metabolic engineering and synthetic biology tools and strategies, our group seeks to expand both the number and diversity of chemical products that can be produced by microbes from renewable resources, as well as to ultimately achieve production metrics enabling their economic viability. Research efforts to date have primarily been centered in two complementary areas, namely i) the engineering of novel biosynthetic pathways for the production of non-natural chemical products, and ii) the systematic engineering of host organisms (including photosynthetic and other non-traditional hosts) as bioproduction platforms. In addition, we are also interested in iii) better understanding and rationally engineering of various industrially-relevant phenotypes, including improved solvent tolerance and enhanced catabolic function, iv) engineering and applying in vivo metabolite biosensors and other synthetic gene circuits as tools for monitoring and regulating metabolic pathways and cellular functions, and v) enzyme evolution and protein engineering to engineer new ‘parts’ for improving various cell functions. As working system, many of our efforts have been focused on developing ‘microbial chemical factories’ for the production of 1) aromatic compounds with applications as both fine and bulk chemicals, 2) monomer compounds as precursors to new classes of renewable plastics, 3) fatty acids and related derivatives with applications ranging from advanced biofuels to fine chemicals, and 4) amino acids of nutritional importance.

Engineering and Investigating Synthetic Microbial Consortia

coming soon

Cyanobacterial ‘Cell Factories’: Tools and Strain Development

coming soon

Bioprocess Engineering for Renewable Fuels and Chemicals Production

In addition to developing better ‘bugs’, we are also interested in engineering better bioprocess with which to enable enhanced production of renewable biofuels and biochemicals. To this end we are working to i) identify, develop, and characterize novel materials and strategies for biofuel and biochemical separation/purification, and ii) engineer integrated bioreactor designs that enable the productivity-limiting effects caused by inhibitory products to be overcome via their in situ recovery. Other areas of interest also include the development of iii) thermochemical processes to convert waste and/or photosynthetic microbial biomass to useful gas and liquid products and iv) photobioreactor designs to maximize CO2 removal and bioproduction metrics by photosynthetic microbes.

Current Projects


Past Projects




We are grateful for all of the support, past and present, that allows us to conduct our research.  Including from these sponsors: