Medium Optimization and Proteome Analysis of Protease Production by Janthinobacterium sp.

Abstract

This study describes the optimization of a culture medium to improve protease production by Janthinobacterium sp. using response surface methodology (RSM) and comparative proteomic analysis. Using a one-variable-at-a-time approach, dextrose, Triton X-100, peptone, and pH were identified as significant factors affecting protease production. The optimized medium resulted in a 6.25-fold increase in protease activity when compared to that in the original medium. To investigate the metabolic changes in the optimized medium, extracellular and intracellular proteins were analyzed by two-dimensional gel electrophoresis. Some proteins essential to cell viability were highly expressed in the optimized medium and the outer membrane protein A was secreted at a higher level. These results can be useful for the industrial application of psychrophiles that produce cold-adapted enzymes.