Elucidation and application of molecular mechanism of preference in microbial predation and phagocytosis

Research Project

Project/Area Number	24658072
Research Category	Grant-in-Aid for Challenging Exploratory Research
Allocation Type	Multi-year Fund
Research Field	Applied microbiology
Research Institution	The University of Tokyo
Principal Investigator	ADACHI Hiroyuki 東京大学, 農学生命科学研究科, 准教授 (00211699)
Research Collaborator	INABA Hironori TERAZAWA Natsumi
Project Period (FY)	2012-04-01 – 2015-03-31
Project Status	Completed (Fiscal Year 2014)
Budget Amount *help	¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000) Fiscal Year 2013: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000) Fiscal Year 2012: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
Keywords	microbial predation / 微生物捕食 / 微生物 / 細胞性粘菌 / 貪食作用
Outline of Final Research Achievements	An assay system was constructed, to examine the ability for bacterial cells to be predated by Dictyostelium cells and form plaques using 96-well plates. By means of this assay system, Keio library, the comprehensive library of knockout mutants of E. coli, was examined twice. As a result, eight mutants were reproducibly identified that showed greatly reduced speed to form plaques. By using 9-cm plates, the results were reproduced for all mutants, and it was also revealed that the slower the mutant cells grew, the slower the plaque spread, suggesting that Dictyostelium cells preferentially predate bacteria that grow faster. The disrupted genes included not only the ones involving growth but also ones whose function is unknown. In addition, a protein of Dictyostelium involving phagocytosis was identified.