title: Pathway for Biodegrading Nodularin (NOD) by Sphingopyxis sp. USTB-05.
abstract: Nodularin (NOD) is greatly produced by Nodularia spumigena and released into the environment when toxic cyanobacterial blooms happened in natural water body, which is seriously harmful to human and animals. The promising bacterial strain of Sphingopyxis sp. USTB-05 was found to have an ability in biodegrading NOD. Initially, 11.6 mg/L of NOD could be completely eliminated within 72 h by whole cells of USTB-05, and within 36 h by its crude enzymes (CEs) of 570 mg/L, respectively. During the enzymatic biodegradation process of NOD, two products were observed on the profiles of HPLC. Based on the analysis of m/z ratios of NOD and its two products on a rapid-resolution liquid chromatogram-mass spectrum (RRLC-MS), we suggested that at least two enzymes of USTB-05 participated in biodegrading NOD. The first enzyme hydrolyzed Arg-Adda peptide bond of cyclic NOD and converted it to linear NOD as the first product. The second enzyme was found to cut off the target peptide bond between Adda and Glu of linearized NOD, and Adda was produced as a second and dead-end product. This finding is very important in both basic research and the application of USTB-05 on the removal of NOD from a water environment.
authors.affiliation: School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China. ustbnanfeng@163.com.
authors.forename: Nan
authors.initials: N
authors.lastname: Feng
authors.affiliation: School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China. ustbyangfan@163.com.
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.affiliation: School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China. haiyan@ustb.edu.cn.
authors.forename: Hai
authors.initials: H
authors.lastname: Yan
authors.affiliation: School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China. chyin@ustb.edu.cn.
authors.forename: Chunhua
authors.initials: C
authors.lastname: Yin
authors.affiliation: School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China. xiaoluliu@ustb.edu.cn.
authors.forename: Xiaolu
authors.initials: X
authors.lastname: Liu
authors.affiliation: School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China. zhanghy@ustb.edu.cn.
authors.forename: Haiyang
authors.initials: H
authors.lastname: Zhang
authors.affiliation: School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China. qianqianxu@ustb.edu.cn.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Xu
authors.affiliation: School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China. lvle@ustb.edu.cn.
authors.forename: Le
authors.initials: L
authors.lastname: Lv
authors.affiliation: School of Architectural and Surveying &amp; Mapping Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China. wanghuasheng2005@126.com.
authors.forename: Huasheng
authors.initials: H
authors.lastname: Wang
mesh_terms: D001673:Biodegradation, Environmental; D002851:Chromatography, High Pressure Liquid; D013058:Mass Spectrometry; D010456:Peptides, Cyclic / Q000378:metabolism*; D042301:Sphingomonadaceae / Q000378:metabolism*
chemical_list: D010456:Peptides, Cyclic; C063998:nodularin
keywords: Sphingopyxis sp. USTB-05; biodegradation pathway; crude enzymes (CEs); nodularin (NOD)