Research Positions for Undergraduates, Spring term 2017

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 cuttingedge

research problems and to learn new skills.

Eligibility:

i) graduation date (B.S.) between 05/18 and 12/19 in BIOL, 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 Spring 2017 for credit, continuation during summer 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 positions available on the following projects:

1. Growth, expression, and purification of two enzymes: HmfF and HmfG

Mentors: Harrison Rose (harrison.rose@gatech.edu) and Dr. Mick Robbins

(john.robbins@chbe.gatech.edu)

HmfF and HmfG are two enzymes from a novel metabolic pathway which can be manipulated to aid in

the production of chemical precursors to bioplastics. HmfF is a reversible decarboxylase - natively it

removes COO- from a carboxylic acid and produces CO2. HmfF requires a relatively unstudied cofactor –

a modified flavin – in order to operate. The ‘apo’ or ‘empty’ form of HmfF without the cofactor is like a

car without an engine. The partner enzyme, HmfG, produces the cofactor. The student’s task will be to

produce these enzymes for further study. To accomplish this task, the student will learn and revise

protocols for cell culture, bacterial fermentation, protein purification, and protein assays.

2. Process design criteria for monomer to bioplastics

Mentor: Harrison Rose (harrison.rose@gatech.edu)

Furan carboxylic acids are important precursors and intermediates in the production of bioplastics. Key

reactions involving these chemical species occur in water at elevated pH (near 8.5). The student’s task

will be to produce sodium salts of these acids and determine their solubilities at elevated pH. To

accomplish this task, the student will work with current analytical techniques, including High

Performance Liquid Chromatography (HPLC) and ultraviolet and visible light spectrophotometry (UVVIS).

The student will also develop a strong understanding of solubility, pH, and ionic strength, including

learning the limitations of the Henderson-Hasselbalch approximation, and what to do when those

limitations must be overcome.

3. Protein engineering of amine dehydrogenase (AmDH) towards aliphatic substrates

Mentor: Robert Franklin (robertfranklin@gatech.edu)

A number of novel amine dehydrogenases (AmDH) have been developed by the Bommarius Lab which

convert prochiral ketones into chiral amine compounds. The focus of this project will be to use protein

engineering to expand the capabilities of our leucine amine dehydrogenase (L-AmDH). This enzyme

converts aliphatic methyl ketones to (R)-amines. The student will produce variants of this enzyme which

are active on precursors to amine compounds with proven disease relevance with the goal of increasing

access to important pharmaceutical ingredients.

The student will learn a host of methods, such as bacterial expression, protein purification using

immobilized metal affinity chromatography (IMAC), as well as characterization of new enzyme variants

via SDS-PAGE for purity assessment, protein concentration assays, and activity assays (UV-VIS, HPLC,

GC). The student will learn how to manipulate DNA to generate new variants using overlap extension

PCR. The project will require knowledge of organic chemistry, biochemistry, and some kinetics.

4. Investigating protein stability of an amine dehydrogenase

Mentor: Dr. Bettina Bommarius (bettina.bommarius@chbe.gatech.edu)

We seek an undergraduate researcher to perform protein stability studies on our recently developed amine

dehydrogenases (AmDHs). AmDH catalyzes the reduction of ketones to enantiomerically pure amines,

which are important synthons in active pharmaceutical ingredients (APIs). The enzyme exhibits unusual

thermostability without introduction of new mutations through chimeric domain shuffling but both

thermal and operational stability seem to decrease with age. The undergraduate will investigate stability

of this enzyme, both long-term resting as well as operational stability, and test stabilizing agents.

The protein is available already expressed in large amounts and after determining initial stability

data further protein engineering is required. The researcher will purify the enzyme from frozen cell mass

and then apply different stresses to the enzyme to investigate its stability. An activity assay as well as

GC/HPLC analysis of product formation is available for determination of operational stability.

5./6. Lignin Value Prior to Pulping

Mentor: Thomas Kwok (tkwok@gatech.edu)

This project allows a student to work at the forefront of sustainability research. Recently funded by the

Agenda 2020 Technology Alliance, this project will provide insights on how the Pulp and Paper industry

can reduce costs and develop new revenue streams. For the Spring 2017, the undergrad will look at either:

(1) the recovery of a solvent, ethylene carbonate, from a lignin solution, or

(2) the characterization of how reactor conditions determine pretreatment efficacy towards delignification

and fiber modification.

Project (1) will explore a liquid-liquid extraction method that adds ethers to alkylene carbonate

solutions to selectively extract the alkylene carbonate. We will apply phase boundary knowledge from

Thermodynamics and Separation classes and will employ HPLC and UV-Vis Spectrophotometry as

characterization techniques. Project (2) will develop a systematic approach to reactor design for ethylene

carbonate pretreatment in a new Parr reactor. Characterization techniques to measure the residual lignin

and fiber properties include UV-Vis spectrophotometry and Simons’ Staining.

The ideal student would be interested in both experimental and computational techniques with the

intention of working for at least a year. Future projects include development of an empirical cost model to

select pretreatment conditions and evaluate the added value to an existing or new pulp mill.