Quantification of bacterial chemotaxis by use of observation of collective motion of cells and mathematical model based on individual behavior

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K03950
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 19010:Fluid engineering-related
• Research Institution: Tottori University
• Principal Investigator: GOTO Tomonobu 鳥取大学, 工学研究科, 教授 (00260654)
• Co-Investigator(Kenkyū-buntansha): 中井 唱 鳥取大学, 工学研究科, 准教授 (80452548)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 走化性 / 細菌 / 集積 / 誘引物質 / 数理モデル

Outline of Final Research Achievements

Accumulation of bacterial cells around several amino acids and swimming motion of individual cell were observed. Two strains of cells were used: One of them is Salmonella typhimurium, SJW1103, which is peritrichous, and the other is Vibrio alginolyticus, YM4, monotrichous. 1) Salmonella cells accumulate more around aspartic acid than around L-serine. 2) Vibrio cells accumulate more around L-serine than around glycine, leucine, alanine. 3) Chemotaxis had been thought to be caused by suppression of tumbles. However, we found that biased reorientation is another cause of chemotaxis. In Salmonella cells, chemotaxis occurs mainly due to the biased reorientation. 4) Numerical simulation including mathematical model for individual behavior of each cell revealed that the difference in individual motion between Salmonella (peritrichous) and Vibrio (monotrichous) produces the difference in number density distribution of cells around an attractant chemical.

Free Research Field

流体工学

Academic Significance and Societal Importance of the Research Achievements

誘引物質に対する細菌の集積速度や誘引物質まわり細菌分布を予測するためには，個々の細菌の運動から集団運動としての走化性の強さを同定する必要がある．このことは，狭い環境下では，細菌の増殖と合わせて生じるぬめりなどの形成の定量評価に寄与するであろうし，広い環境下では，食物連鎖の中の細菌の役割を明らかにすることに繋がる．また，有用細菌の培養条件の設定や，最近試みられている集団運動の制御にも寄与するものと考えられる．
ここで得られた研究成果は，走化性の強さを同定するための方法の開発の基礎となると同時に，走化性の強さを示すデータの一部となる．