Study on the genes that promote bacterial colony formation

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K14688
• 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: Masaki Haruhiko 東京大学, 大学院農学生命科学研究科(農学部), 教授 (50134515)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: cAMP / CRP / CyaA / コロニー / RpoS / 飢餓ストレス / VBNC / RNA-seq

Outline of Final Research Achievements

On exposure to cold starvation, Escherichia coli falls into a viable but non-culturable state, where colony formation is lost in spite of retaining signs of viability. We hypothesized that, during cold starvation, specific gene expressions important for colony formation are diminished and that boosting such gene functions would restrain cells from falling into the low-colony state. From the ASKA library containing all E. coli ORFs, we screened such genes restoring the diminished functions.
When seven such candidate clones are put in competition in the ability to survive against cold starvation, the winner was cpdA, encoding cAMP phosphodiesterase, suggesting that cAMP is a negative regulator in colony formation. In fact, cyaA or crp mutants kept high colony formation for 30 days in starvation. Assuming that a critical gene determining colony formation is under the control of cAMP-CRP, we are seeking it by RNA-seq, though too many genes change their expressions in response to cAMP-CRP

Free Research Field

微生物学、分子生物学