Format

Send to

Choose Destination
Sci Total Environ. 2019 Nov 10;690:1178-1189. doi: 10.1016/j.scitotenv.2019.07.098. Epub 2019 Jul 8.

Arsenic-resistance mechanisms in bacterium Leclercia adecarboxylata strain As3-1: Biochemical and genomic analyses.

Author information

1
Quangang Petrochemical Research Institute, Fujian Normal University, Quanzhou, Fujian 362801, China; College of Environmental Science and Engineering, Fujian Normal University, Fuzhou, Fujian 350007, China; Fujian Key Laboratory of Pollution Control and Resource Reuse, Fuzhou 350007, China.
2
School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China.
3
Quangang Petrochemical Research Institute, Fujian Normal University, Quanzhou, Fujian 362801, China.
4
School of the Environment, Nanjing Normal University, Nanjing, Jiangsu 210023, China.
5
Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, United States.
6
Quangang Petrochemical Research Institute, Fujian Normal University, Quanzhou, Fujian 362801, China; Innovative Center for Eco-Friendly Polymeric Materials, Quanzhou, Fujian 362801, China. Electronic address: dlchen@fjnu.edu.cn.
7
College of Environmental Science and Engineering, Fujian Normal University, Fuzhou, Fujian 350007, China; Soil and Water Sciences Department, University of Florida, Gainesville, FL 32611, United States. Electronic address: lqma@ufl.edu.

Abstract

Microbial arsenic transformation is important in As biogeochemical cycles in the environment. In this study, a new As-resistant bacterial strain Leclercia adecarboxylata As3-1 was isolated and its associated mechanisms in As resistance and detoxification were evaluated based on genome sequencing and gene annotations. After subjecting strain As3-1 to medium containing arsenate (AsV), AsV reduction occurred and an AsV-enhanced bacterial growth was observed. Strain As3-1 lacked arsenite (AsIII) oxidation ability and displayed lower AsIII resistance than AsV, probably due to its higher AsIII accumulation. Polymerase chain reaction and phylogenetic analysis showed that strain As3-1 harbored a typical AsV reductase gene (arsC) on the plasmids. Genome sequencing and gene annotations identified four operons phoUpstBACS, arsHRBC, arsCRDABC and ttrRSBCA, with 8 additional genes outside the operons that might have involved in As resistance and detoxification in strain As3-1. These included 5 arsC genes explaining why strain As3-1 tolerated high AsV concentrations. Besides ArsC, TtrB, TtrC and TtrA proteins could also be involved in AsV reduction and consequent energy acquisition for bacterial growth. Our data provided a new example of diverse As-regulating systems and AsV-enhanced growth without ArrA in bacteria. The information helps to understand the role of As in selecting microbial systems that can transform and utilize As.

KEYWORDS:

Arsenate reductase gene; Arsenic-dependent growth; Horizontal gene transfer (HGT); Operon; Tetrathionate

PMID:
31470481
DOI:
10.1016/j.scitotenv.2019.07.098
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center