Expression dynamics of arsenic-metabolizing genes in a dissimilatory arsenate-reducing bacterium Geobacter sp. OR-1

2016 Fiscal Year Final Research Report

• Project/Area Number: 26450086
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Applied microbiology
• Research Institution: Chiba University
• Principal Investigator: AMACHI SEIGO 千葉大学, 大学院園芸学研究科, 教授 (80323393)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: ヒ素 / 汚染 / 溶出 / Geobacter / ヒ酸還元 / arrA / arsC

Outline of Final Research Achievements

Arsenic (As) is released from anaerobic sediments into groundwater as arsenite, and dissimilatory arsenate-reducing bacteria (DARB) may play important roles in As release. Geobacter sp. OR-1, one of DARB, has a variety of As-metabolizing genes such as dissimilatory arsenate reductase genes (arrAB) and genes for As resistance (arsACDR) in its genome. The aim of this study was to understand expression dynamics of these genes or proteins in strain OR-1. Transcriptional analysis revealed that most of As-metabolizing genes were induced by As, and that the expression of arrA and arsC was 52 and 260 times higher in the presence of As, respectively. Comprehensive proteomic analysis showed that proteins involved in oxidative stress response, protein folding, molecular chaperones, and sulfur metabolism were also expressed cooperatively in the presence of As. Our results shed light on how microbes cope with this toxic metalloid, and play an important role in the transfer of As in nature.

Free Research Field

環境微生物学