Research conducted by a team of Stanislaus State students, led by Associate Professor of Microbiology Choong-Min Kang, could help cut agriculture costs and speed up production of a vital ingredient in livestock feed.

Dr. Kang and his team researched L-threonine, an important amino acid in livestock diets. L-threonine is produced via a biosynthetic pathway involving the enzyme ThrB. The challenge in Dr. Kang’s research was to maximize L-threonine production while avoiding the feedback inhibition, or slowdown effect, that occurs when L-threonine accumulates in an organism. For this study, that organism is Escherichia coli.

Past attempts by other researchers to remove the feedback inhibition in ThrB failed because any mutation also killed the enzyme’s catalytic ability. However, based on the 3-D structure of ThrB, Dr. Kang and his team found a specific amino acid change that eliminates the feedback inhibition without losing the catalytic activity.

Participating in this research were Stanislaus State undergraduate students Erik Larsen, Kristina Kozlov, Carla Antypas, Juan Montalvo, Paul Cordova, and Rebekah Dial; postdoctoral scholar Dr. Younghwa Kim; and visiting student from Korea, Sung-Kwon Lee.

“Nothing reinforces the concepts learned in a classroom like the actual real-life experiences one may obtain while working in a laboratory,” says Antypas. “Working on a project such as this one, and working on a research team, is an invaluable experience that any student who is interested in science should have.”