Isolation of a 3-hydroxypyridine degrading bacterium, Agrobacterium sp. DW-1, and its proposed degradation pathway

Shuxue Zhao,Lizhong Guo,Hao Yu,Chunhui Hu,Kuiran Li

doi:10.1186/s13568-019-0782-9

Shuxue Zhao, Lizhong Guo + Show 3 more

Open Access

https://doi.org/10.1186/s13568-019-0782-9

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Abstract

A 3-hydroxypyridine degrading bacterium, designated strain DW-1, was isolated from petroleum contaminated soil in Liao River China. 16S rRNA-based phylogenetic analysis indicates that strain DW-1 belongs to genus Agrobacterium. The optimal cultivation temperature and pH for strain DW-1 with 3-hydroxypyridine were 30 °C and 8.0, respectively. Under optimal conditions, strain DW-1 could completely degrade up to 1500 mg/L of 3-hydroxypyridine in 66 h. The 3-hydroxypyridine degradation pathway of strain DW-1 was suggested by HPLC and LC–MS analysis. The first reaction of 3-hydroxypyridine degradation in strain DW-1 was α-hydroxylation so that the major metabolite 2,5-dihydroxypyridine was produced, and then 2,5-dihydroxypyridine was transformed by a Fe2+-dependent dioxygenase to form N-formylmaleamic acid. N-Formylmaleamic acid will be transformed to maleic acid and fumaric acid through maleamic acid. This is the first report of the 3-hydroxypyridine degradation pathway and the utilization of 3-hydroxypyridine by a Agrobacterium sp. It may be potentially used for the bioremediation of environments polluted with 3-hydroxypyridine.

Highlights

Pyridine and its derivatives compose one of the largest classes of N-heterocyclics (Fetzner 1998; Kaiser et al 1996; O’Hagan 2000; Scriven and Murugan 1996; Sims et al 1989)
A comparison of the 16S rRNA gene sequence of strain DW-1 with those of other members of the genus Agrobacterium was performed based on the neighbourjoining methods (Fig. 2)
Strain DW-1 exhibited the highest similarity (96.9%) to Agrobacterium nepotum LMG 26435, which is higher than any other genus

Summary

Introduction

Pyridine and its derivatives compose one of the largest classes of N-heterocyclics (Fetzner 1998; Kaiser et al 1996; O’Hagan 2000; Scriven and Murugan 1996; Sims et al 1989). They were mainly produced by mining industry, petroleum industry and chemical synthesis industry. A few intermediates have been reported during 3-hydroxypyridine degradation, the complete degradation pathway of 3-hydroxypyridine remains enigmatic (Cain et al 1974; Kaiser et al 1996). Deciphering the degradation pathway of 3-hydroxypyridine is of scientific significant since it will be helpful for the microbial degradation of 3-hydroxypyridine and related pollutants

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