Engineer metabolic pathways to produce natural products in microbial cell factories • Optimized metabolic pathways for two molecules to improve the yield, productivity, and tier• Conducted library screening using a competitive assay to identify the bottleneck of production• Designed DNA constructs using computational tools for optimizing metabolic pathways• Analyzed omics/fermentation data to inform rational pathway designs • Proposed and executed strategy that led to a 70% reduction in byproduct to target product ratio • Conducted the design of the experiment to identify the key limiting factor for pathway optimization• Collaborated with multiple functional groups frequently to build and screen top strain construct

Engineered Rhodopseudomoman palustris TIE-1 for n-butanol production•Constructed a plasmid-based n-butanol biosynthesis pathway through DNA assembly•Prepared cell lysate and performed enzyme activity assays of three enzymes involved in the pathway•Introduced the biosynthesis pathway into wildtype and different knockout mutants through conjugation and performed RT-qPCR and enzyme activity assays to characterize the heterologous gene expressions•Tested sixteen cultivation conditions (including microbial electrosynthesis) to investigate optimum carbon, electron, and nitrogen sources•Hypothesized that substrate availability could be the barrier for n-butanol biosynthesis and tested the hypothesis by generating mutants lacking competing pathways through microbial genome engineering •Performed statistical analysis of production from different mutants and cultivation conditions in Python and identified that the mutant increased the titers and yields by over 100% •Achieved high carbon (~5%) and electron (~12%) conversion efficiency using slow/non-growing cells Genetic tool development for Rhodopseudomonas palustris TIE-1•Designed and built both plasmid-based and genome-based phage recombination system for inserting target genes rapidly and accurately into glmUSX-recG locus on the TIE-1 genome •Accelerated the target gene integration by 50% and improved editing efficiency by 100%•Developed an electroporation protocol for TIE-1 that introduced plasmid 40% quicker than the conjugation process while avoiding using a donor strain and auxotrophic selection•Identified genes that facilitate bioplastic production and improved the titer by ~ 4-fold through incorporating extra copies of these genes into the TIE-1 genome by the phage recombination system•Created multiple suicide plasmids for allelic exchange cloning in TIE-1•Designed and established a CRISPR-Cas9 system for rapid mutant generation in TIE-1

Course name: Microbiology•Led discussion for a group of 5 students every week•Wrote exam questions for all three exams•Taught one of the lectures (70+ students) as a guest speaker

Course name: DNA manipulationMain responsibility:•Modified the existing experiment protocol according to the new project•Explained the experiment protocol to students and supervised students during the experiments

Course name: Unit operation Lab•Established the experiment protocol for the new instruments•Explained the experiment protocol to students and supervised students during the experiments

Market and feasibility assessment of grant proposals • Examined the commercialization potential of several academic grant proposals • Ranked the proposals based on the market need, impact, and the potential for market entry • Compiled written report and presented weekly to teammates with a multi-disciplinary background

Investigated relationship between growth rate and plasmid yield in E. coli•Accumulated three times more plasmid (per gram dry cell weight) by introducing point mutation, shifting the growth temperature, and enabling the cell to use sucrose after glucose is exhausted •Modified flux balance analysis model of E. coli’s central metabolism, based on an understanding of the microbial metabolism•Established a linear relationship between growth rate and fluxes in central metabolism using a flux balance analysis model in General Algebraic Modeling System

Increasing 2-keto-L-gulonic (2-KLG) acid titer in Ketogulonigenium vulgare •Engineered 2-KLG acid biosynthesis pathways with various enzyme and cofactor combinations•Tested metabolic and physiological performance by HPLC and enzyme activity assay•Hypothesized that cofactor amount could be the barrier for optimized production and tested the hypothesis by supply the cofactor the culture, which increased 2-KLG titer by 50%•Improved cofactor production by 4-fold through overexpression of multiple genes on a plasmid•Increased the 2-KLG acid titer by 20% using a K. vulgare–Bacillus cereus consortium•Adapted the consortium towards high sugar cultural condition through adaptive evolution