Rapid purification of bacteriophage endolysin TSPphg and its exogenous treatment could act as an alternative bacterial cell disruption method

Bacteriophage endolysins have long been demonstrated to be effective enzybiotics, and have the potential value in the areas of food, agricultural, and industrial science. Traditionally, extraction of recombinant proteins from bacterium E. coli is achieved by chemical, biological or mechanical disruption methods. Here, we present heat treatment, a simple and highly effective method that differs from the conventional ones, for disruption of E. coli cells to extract recombinant TSPphg, an endolysin originated from thermophilic bacteriophage TSP4. In addition, we found that exogenous TSPphg treatment is able to disrupt E. coli cell and release its intracellular proteins, suggesting its great potentiality to be developed as an alternative bacterial cell disruption method. Moreover, the large scale purification of TSPphg by heat treatment can be carried out directly in fermentation broth in situ without complex downstream processing, which may make it a more applicable approach for commercial scale processes. Our findings shed light on recovery of recombinant thermostable proteins and strategy of bacterial cell disruption.