The Bommarius lab seeks undergraduate students interested in challenging research!
The Bommarius laboratory (ChBE, CHEM, Bioengineering) specializes in biocatalysis, green chemistry, protein stability, and biochemical engineering. We seek self-motivated, hard-working student researchers interested to continue for a PhD and/or MD after college, to work on cutting-edge research problems and to learn new skills.
Eligibility:
i) graduation date (B.S.) between 05/14 and 12/15 in BIOL, BMED, CEE, ChBE, or CHEM
ii) GPA at Georgia Tech > 3.30, preferably > 3.5
iii) basic laboratory skills, enthusiasm, self-motivation, flexibility, independence
iv) start in Fall 2013 for credit, continuation during 2014 possible and expected
Interested?: Please email resume (incl.i) major, ii) GPA, and iii) expected graduation date) to mentor and to Prof. Andreas S. Bommarius (andreas.bommarius@chbe.gatech.edu).
Interviews with mentor: any time; feedback: less than 1 day later; decision asap after agreement among student, mentor, and faculty advisor.
We have a position available on the following projects:
1. Deep eutectic solvents for the pretreatment of cellulose
Cellulose is the most abundant biomaterial known and is considered a key target for replacement of fossil fuels. Due to its partially crystalline nature, cellulose is not soluble in water or most organic liquids. Eutectic mixtures of salts sometimes melt below room temperature. We will investigate the solubility and structure (crystallinity) of cellulose in such liquids.
The student will learn to compose and identify a eutectic medium, measure and interpret crystallinity of cellulose, and to employ cellulose and lignocellulosic materials. Key experiments will involve testing renewable materials as components of the eutectic system, testing cellulose crystallinity via X-ray diffractometry, and measuring hydrolysis to oligosaccharides. The work will require some knowledge of physical chemistry.
Mentors: Yuzhi Kang (ykang41@gatech.edu), Dr. Minjeong Sohn (minjeong.sohn@chbe. gatech.edu)
2. Green oxo synthesis: improvement of alcohol oxidase (AOX) to increased activity against butanol for conversion to butyraldehyde.
Aldehydes are commonly obtained through oxo synthesis or hydroformylation, via addition of CO and H2 to alkenes. We propose to generate aldehydes via selective oxidation of the corresponding alcohols, many of them available inexpensively through their use as biofuels.
We seek to improve the specific activity of alcohol oxidase from yeast as well as substrate binding and temperature stability, by applying the protein engineering toolbox established in our lab. We will identify hotspots on the amino acid sequence that control activity and stability, and then proceed to create and assay variants for the trait we seek to improve.
The students will learn how to cultivate, express, and harvest proteins from Pichia pastoris and then learn how to use the FPLC system for protein purification. UV spec assays and protein assays will be taught for characterization of protein variants. This project requires knowledge of biochemistry and some kinetics.
Mentor: Dr. Bettina Bommarius (bettina.bommarius@chbe.gatech.edu)
3. Redesign of amine dehydrogenase via protein engineering
Amine dehydrogenase (AmDH), developed in our lab, catalyzes the reduction of ketones to enantiomeri-cally pure amines, which are important building blocks in syntheses of active pharmaceutical ingredients (APIs). Using the established library screen to investigate hot spot sites in amine dehydrogenase, the student will start with an already cloned library to screen colonies for expression and activity of the new variants in regard to higher activity and broader selectivity. Approximately between 100-1000 colonies will be screened during the process of investigation of the 2 amino acid sites making up the hot spot.
The student will learn protein expression and purification techniques along with assays to explore and confirm enzymatic activity using state-of-the-art technologies in protein engineering such as AKTA Explorer for protein purification, gas chromatography, circular dichroism, and mutational library construction. The work will require knowledge of organic chemistry, biochemistry, and kinetics.
Mentors: Dr. Bettina Bommarius (bettina.bommarius@chbe.gatech.edu) and Samantha Au (sau3@gatech.edu)
4. Large-scale purification protocol for amine dehydrogenases
Application of amine dehydrogenase (AmDH) in the synthesis of Active Pharmaceutical Ingredients (APIs) requires its purification after fermentation. We have conducted pilot-scale fermentation and now need to develop a purification protocol that does not require any chromatographic steps, as these are too expensive for large-scale downstream processing.
Instead, we will focus on protein extraction in aqueous two-phase systems (ATPS), with ammonium sulfate in the top phase and polyethylene glycol (PEG) polymer in the bottom phase. We will determine the phase diagram with and without enzyme, and its variation in temperature, salt and PEG concentration as well as pH of the solution. After determining the optimal conditions, we will then develop the detailed purification protocol, with protein purity and yield as our main targets, and conduct proof-of-principle trial runs on pilot scale.
The student will learn the full range of protein purification techniques along with assays for protein content and activity, using state-of-the-art technologies in protein engineering such as AKTA Explorer for protein purification, UV/VIS spectroscopy, and gas chromatography. The work will require knowledge of thermodynamics and separations.
Mentors: Dr. Bettina Bommarius (bettina.bommarius@chbe.gatech.edu) and Samantha Au (sau3@gatech.edu)
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