Theses and Dissertations


Neeti Dahal

Issuing Body

Mississippi State University


Smith, L. James

Committee Member

Gordon, M. Donna

Committee Member

Pharr, Todd G.

Committee Member

Donaldson, R. Janet

Date of Degree


Document Type

Graduate Thesis - Open Access

Degree Name

Master of Science


College of Arts and Sciences


Department of Biological Sciences


Mutacin 1140, a class 1 bacteriocin, is produced by Streptococcus mutans and belongs to the type A lantibiotic family. Experiments were done to optimize production of mutacin 1140 in minimal media enabling a more cost efficient downstream purification method. The development of a small volume fermentation method enabled a rapid screen of several variables in a standard shaking incubator. This method provided a fast approach for determining components that promote mutacin 1140 production in minimal media broth. Lactose was determined to be the optimal carbon source for mutacin 1140 production. High concentrations of CaCl2 (0.3% w/v) and MgSO4 (0.77% w/v) promoted an increase in mutacin 1140 production, while ZnCl2 and FeCl3 appeared to impair production. Optimization of mutacin 1140 production in minimal media resulted in more than a 100old increase in production compared to the base medium used to begin our optimizations. The yield has been estimated by RP-HPLC to be 10 mg/L.



Streptococcus mutans||mutacin 1140||minimal media||lantibiotic||fermentation