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Rensselaer Polytechnic Institute (RPI)

Asher Williams

Ph.D. Chemical Engineering

Hometown: Arima, Trinidad, and Tobago

Undergraduate Institution & Year of Graduation: NYU Tandon School of Engineering, 2015

RPI Department: Chemical and Biological Engineering

Faculty Advisor: Dr. Mattheos Koffas and Dr. Robert Linhardt


Describe your graduate research and its purpose/applications

My research involves collaborative projects focused on engineering microbial metabolism of various organisms to produce polysaccharides of pharmaceutical and nutraceutical relevance – particularly the glycosaminoglycans heparin and chondroitin sulfate. They are currently mainly extracted and purified from animal tissues, where factors like manufacturing processes and the presence of contaminants affect overall safety and biological and pharmacological efficacy.  My work investigates methodologies for the laboratory production of chondroitin sulfate in Escherichia coli, and heparosan, a valuable precursor to heparin, in Bacillus megaterium. A biotransformation scheme is being used for in vitro production of sulfated polysaccharides using multiple E. coli strains, specifically concentrating on the expression, activity, and stability improvement of several biosynthetic pathway enzymes through protein engineering.

What made you decide to attend Rensselaer? Why did you select Rensselaer for your [degree program]?

In addition to visiting RPI and speaking with faculty, I reached out to Ph.D. students in my department and minority graduate students to learn about their experience at RPI and determine if it would be a good fit for me. I was interested in the research being conducted within the department and attracted to the prospect of working in an interdisciplinary building equipped with world-class facilities, with opportunities for collaboration outside of my department.

I also liked the structure of the Chemical Engineering Ph.D. program, where classes are concentrated within the first 2 years, followed by full-time research, but still allowing the opportunity to take or audit classes as desired.

As an international student, I had already developed a base in the Tri-state area and RPI’s location would allow me to see family and friends without an overwhelming amount of hassle or expense. Being able to get out of Troy occasionally and have access to loved ones was definitely an important factor for me. Additionally, the funding offered by RPI was one of my best options.

What aspects of the Ph.D. program do you value most?

As a co-advised student, I have the opportunity to be immersed in two groups consisting of students from varying backgrounds and degree programs. This has placed me in contact with a range of research areas and given me the chance to learn skills that I would not have typically been exposed to, such as LC-MS and NMR analytical techniques.

I appreciate the research freedom afforded to me by my advisors, who provide guidance but are relatively hands-off and allow me to take my projects in whichever direction I choose. Having two research advisors means that I can draw on their respective strengths and backgrounds for feedback and advice. They also support my research collaborations within and outside of our groups and have encouraged me to present my research at conferences, where I can network and meet new academic peers.

Tell us about your background and accomplishments in college and/or work experience.

My undergraduate studies in Chemical and Biomolecular Engineering were funded by a National Open Scholarship from the Government of Trinidad & Tobago and I was also a Women in Science Scholar with the NYU College of Arts & Science. During my senior year at NYU, I worked as an undergraduate researcher helping to develop a new insertional fusion method of stabilizing various enzymes without restricting available sequence spaces or compromising other intrinsic properties. After completing my undergraduate degree, I worked as a summer intern at the NASA Ames Research Center before starting the Chemical Engineering Ph.D. graduate program at Rensselaer. During my internship at NASA I developed a prototype design and ran preliminary experimental tests on a disposable bioreactor for in situ production of the carotenoids in space, using an engineered strain of the yeast Saccharomyces cerevisiae. Since joining RPI, I have had the privilege of presenting my work at conferences and publishing papers in several peer-reviewed journals, with the funding support of an RPI Presidential Graduate Research Fellowship.