The Genome Analysis of Methylobacterium populi YC-XJ1 with Diverse Xenobiotics Biodegrading Capacity and Degradation Characteristics of Related Hydrolase.

Xianjun Li,Yanchun Yan,Aikebaier Reheman,Junhuan Wang,Yang Jia

doi:10.3390/ijms21124436

Abstract

Methylobacterium populi YC-XJ1 isolated from desert soil exhibited a diverse degrading ability towards aromatic oxyphenoxypropionic acid esters (AOPPs) herbicide, phthalate esters (PAEs), organophosphorus flame retardants (OPFRs), chlorpyrifos and phoxim. The genome of YC-XJ1 was sequenced and analyzed systematically. YC-XJ1 contained a large number of exogenous compounds degradation pathways and hydrolase resources. The quizalofop-p-ethyl (QPE) degrading gene qpeh2 and diethyl phthalate (DEP) degrading gene deph1 were cloned and expressed. The characteristics of corresponding hydrolases were investigated. The specific activity of recombinant QPEH2 was 0.1 ± 0.02 U mg−1 for QPE with kcat/Km values of 1.8 ± 0.016 (mM−1·s−1). The specific activity of recombinant DEPH1 was 0.1 ± 0.02 U mg−1 for DEP with kcat/Km values of 0.8 ± 0.02 (mM−1·s−1). This work systematically illuminated the metabolic versatility of strain YC-XJ1 via the combination of genomics analysis and laboratory experiments. These results suggested that strain YC-XJ1 with diverse xenobiotics biodegrading capacity was a promising candidate for the bioremediation of polluted sites.

Highlights

Quizalofop-p-ethyl (QPE), a unitary R configuration aromatic oxyphenoxypropionic acid esters (AOPPs) herbicide, was predicted to rapidly increase in coming years in an effort to overcome the widespread appearance of glyphosate-resistant weeds [1]
We report the Methylobacterium populi YC-XJ1 with diverse degrading function isolated from desert soil
It was hoped that the Methylobacterium populi YC-XJ1 could be modified as engineered bacteria for practical application in bioremediation of polluted sites

Summary

Introduction

Quizalofop-p-ethyl (QPE), a unitary R configuration aromatic oxyphenoxypropionic acid esters (AOPPs) herbicide, was predicted to rapidly increase in coming years in an effort to overcome the widespread appearance of glyphosate-resistant weeds [1]. An investigation on particulate and gas-phase distribution of PAEs in Nanjing (China), approximately 75 to 89.2% of phthalate esters were present in the atmosphere in vapor form, DEP is 3.4 ng m−3 [8]. Due to the widespread use of DEP in personal care products, plastics and medical devices, some detrimental effects had been reported, such as chronic toxicity in male wistar rats [11]; hepatotoxicity to 21-day-old male and female weanling pups of Wistar rats [12]; causing changes of certain liver and muscle enzyme activity to freshwater fish Cirrhina mrigala [13]; causing severe impairment of lipid metabolism coupled with toxic injury of the liver in young male Sprague-Dawley rats [14]; causing neurotoxicity in zebrafish embryos [15]

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Conclusion