클로닝 기법을 이용한 Pseudomonas aeruginosa UCBPP PA14 유래 살조물질 관련 유전자 탐색

Abstract

Abstract Cloning and investigating the gene cluster related to algicidal substance produced by Pseudomonas aeruginosa PA14

Jo, Seong-Hyeon Department of Life Science The Graduate School Hanyang University

To develop an effective, stable and eco-friendly strategy using algicidal substance(s) derived from bacteria, we investigated the gene cluster and substance related to algicidal activity of Pseudomonas aeruginosa UCB-PP PA14 (hereafter PA14) known as algicidal bacteria against Microcystis aeruginosa. In the present study, PA14 was found to show the algicidal ability by secreted substance(s). Thus, a genomic DNA library of PA14 was constructed to screen this algicidal substance(s) and the related gene cluster. Of the 105 transformants, PA14I51 showed the highest algicidal activity (82.6%), and the insert of cosmid cPA14I51 was sequenced. We found the genes (aprI and A) encoding the alkaline protease (AprA) known to function as virulence factors by degrading host tissue. The aprI and aprA genes were subcloned, and derivative PA14IL0301 revealed high algicidal effect (51.6%). This result indicated that aprI and aprA were related to algicidal activity. Furthermore, other apr genes (aprD, E, F, and X) encoding the AprA secretion proteins were subcloned in order to investigate whether AprA secretion machinery improve the algicidal activity. The derivative PA14IL0804 showed augmented activity (89.7%). Therefore, it was discovered that all of the apr gene cluster (aprI, A, D, E, F, and X) were related to the algicidal activity and these were needed for effective and stable inhibition of algal growth. Consequently, we suggest that the alkaline protease encoded by apr gene may function as a potent algicide when it is equipped with its secretion system.