A minority population bacterium enhances the activity of a majority population bacterium

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K18820
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 22:Civil engineering and related fields
• Research Institution: Gunma University
• Principal Investigator: Ito Tsukasa 群馬大学, 大学院理工学府, 准教授 (80431708)
• Project Period (FY): 2022-06-30 – 2024-03-31
• Keywords: 相互作用 / 多様性 / Bacillus / 持続可能性 / 微生物

Outline of Final Research Achievements

The activity of Enterococcus faecalis T6a1 was enhanced by culturing with Bacillus subtilis S4ga at a population rate of 1% or less (~0.01%). There are at least three reasons for this. 1) In the presence of 1% S4ga, the degradation of hydrogen peroxide was accelerated, reducing the damage to T6a1 cells caused by hydrogen peroxide. 2) S4ga at a population rate of 1% or less consumed dissolved oxygen in the culture medium, creating an anoxic environment for a long period of time that made it easier for T6a1 to maintain its activity. 3) A cycle of "cell division → elution of cellular contents due to autolysis → dissolution and utilization of the cellular materials eluted by protease." occurred in T6a1.

Free Research Field

微生物生態学

Academic Significance and Societal Importance of the Research Achievements

自然環境中ではほとんどの微生物は様々な微生物が共存した“微生物群集”を形成して存在している。そのため微生物群集や群集中の個々の微生物の機能を評価・制御する上で生物学的因子についての理解は重要である。しかしながら、これまでの考慮されてきた微生物の制御因子は、温度や圧力などの物理的因子とpHや酸素や基質濃度などの化学的因子であり、微生物群集としての理解や制御には繋がりにくい。本研究の成果は、ごくわずか存在割合の微生物が系全体に与えることを明らかにしたものであり、微生物の機能を評価・制御する上で考慮すべきあらたな生物学的因子になり得ると考えられた。