Exploration of unculturable bacteria which can be isolated under the co-incubation of protozoa

2015 Fiscal Year Final Research Report

• Project/Area Number: 25640118
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Conservation of biological resources
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: Tarao Mitsunori 東京農工大学, (連合)農学研究科(研究院), 准教授 (60282802)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 微生物保全 / 生物多様性 / 微生物多様性 / 異種間相互作用 / 原生動物 / 細菌群集構造

Outline of Final Research Achievements

This study hypothesised that some bacteria utilise protozoan extracellular exudates (PECEs), as signal factors or growth promotion factors. By using PECEs derived from ciliate Tetrahymena thermophia, as a model protozoa, two outcomes were obtained. (1) Bacterial communities of freshwater were incubated in the liquid medium with PECEs, and the community structure was analysed sequentially. As a result, it is suggested that PECEs contribute to stabilise bacterial community structure. (2) Bacterial communities of freshwater were incubated on the agar plate with PECEs. As a result, some bacterial strains which formed colonies only on the agar plate with PECEs were isolated. The isolates did not form colonies on the agar plate without PECEs. These results suggest that some bacterial strains in natural environments are stimulated their growth or metabolic activities by PECEs.

Free Research Field

環境微生物学