Isolation And Identification Of A Novel Species Of The Phenylobacterium And Its Phenol Degradation Characteristics

Phenol is an important industrial commodity and chemical raw material,but phenol is very toxic and has a serious destructive effect on the environment and even living organisms,therefore,as a major producer and user of phenol in China,the treatment of phenol pollution is increasingly important.At present,domestic and foreign phenol pollution treatment means mainly physical,chemical and bioremediation methods,among which physical and chemical methods have certain limitations,bioremediation method has the advantages of lower cost,good treatment effect and friendly to the environment.However,in industrial production,the main form of phenol pollution is coking wastewater,which has a complex composition and contains some pollutants that are difficult to biodegrade in addition to phenol,and is generally pretreated by chemical oxidation and other means before entering the biodegradation stage,thus leading to the formation of a micro-oxidation environment with residues such as reactive oxygen radicals generated by pretreatment in the water column,which may adversely affect the subsequent biodegradation.In this study,we obtained a strain LH3H17 with good antioxidant capacity and the ability to use phenol as a single carbon source by isolating,screening and culturing microorganisms collected from the moraine at the front edge of Tiger Gully 12 glacier,and identified a new species of the genus Phenylobacterium by multiphase taxonomic analysis and genomic analysis.We investigated the phenol degradation capacity,optimized the degradation conditions,studied the changes of phenol degradation capacity under micro-oxidation conditions,and compared the metabolome of phenol degradation of LH3H17 and phenol degradation under micro-oxidation conditions.The results of the study showed that:1.Strain LH3H17 was isolated and screened from the moraine at the front edge of Tiger Gully 12 glacier,and is a strain with some antioxidant capacity and can use phenol as a carbon source.LH3H17 was identified as: LH3H17 colonies were white,the bacterium is rod-shaped,optimum temperature of 30 ℃,optimum p H of 7,optimum Na Cl concentration of 0%,optimum medium of R2 A.respiratory quinone was ubiquinone-10,major fatty acids were: C14:0,C16:0,C16:1 w6c/C16:1 w7 c and C18.1 w6 c.1 w6 c.the major polar lipids included PE,DPG,etc.LH3H17 and the reference model strain were below the threshold of the same species in terms of 16 S r RNA,ANI,AAI and DDH value,and belonged to different species with 68.32% genomic G+C content.In summary,combining phenotypic characteristics and genetic characterization can identify strain LH3H17 as a new species of the genus Phenylobacterium.The Gen Bank accession numbers of the genome sequence and16 S r RNA gene sequence are CP101283 and OL842161,respectively,for the antioxidant ability of Phenylobacterium antioxidans.2.The strain LH3H17 has strong tolerance to phenol,and the survival rate of the strain remained above 90% at 0-800 mg/L phenol concentration and around 50% at 1500 mg/L phenol concentration.The initial concentration of phenol has less influence on the growth of the strain in the range of 0-800 mg/L to set the initial concentration of phenol gradient for the determination of the degradation rate,and optimize the conditions,the results for the best conditions for the degradation of phenol strain LH3H17 is the temperature of 30 ℃,p H 7,Na Cl concentration of 0%,48 h to degrade 300 mg/L concentration of phenol and the degradation rate is close to 100%.3.Because strain LH3H17 has good antioxidant capacity and phenol degradation capacity,a study of phenol degradation capacity of strain LH3H17 under microoxidation conditions was conducted.The experimental results showed that the phenol degradation rate of strain LH3H17 increased under microoxidation conditions,and the degradation rate of phenol at a concentration of 300 mg/L reached more than 90% at 36 h.It proved that the micro-oxidation environment helped the degradation of phenol by strain LH3H17,indicating that the strain can better adapt to the environment of coking wastewater treatment process and provide a better germplasm resource for the pollution treatment of phenol.4.In a non-targeted metabolomic study of untreated strains,strains undergoing phenol degradation,and strains undergoing phenol degradation under microoxidation conditions,the three hierarchical classifications of metabolites indicated that strain LH3H17 had a strong biodegradation capacity.The differential metabolites produced by strain LH3H17 during phenol degradation under microoxidation conditions were substantially higher than those produced during phenol degradation alone,and its antioxidant capacity played a role in the metabolic process of phenol degradation by microoxidation environment.The ABC transporter protein metabolic pathway of the differential metabolite KEGG metabolic pathway was significantly different in both treatment groups,and the ABC transporter protein was protective against phenol as well as hydrogen peroxide stimulation of the strain.Significantly different metabolic pathways pantothenic acid and Co A biosynthetic pathway of phenol degradation by the strain under microoxidative conditions were related to the antioxidant capacity of the strain,pantothenic acid could protect the strain in the oxidizing environment and thus ensure the phenol degradation capacity of the strain under oxidative conditions.