title: Enrichment of denitratating bacteria from a methylotrophic denitrifying culture.
abstract: Denitratation (nitrite produced from nitrate), has the potential applications in wastewater treatment by combining with ANAMMOX process. The occurrence of denitratation has been shown to be effected qualitatively by various parameters in the environment. A more quantitative understanding can be obtained using enrichment cultures in lab-scale experiments, yet information on the enrichment of functional microorganisms responsible for denitratation is lacking. In this study, a stable denitratation-dominated culture was obtained from methylotrophic denitrifying culture. The results showed that, besides the substitution of acetate for methanol, the lasting starvation following saturation of electron donor was another pivotal selection pressure that favored the growth of denitratating bacteria, which was supported by the distinctive physiological strategy involving the higher growth rate combining with larger poly-hydroxybutyrate (PHB) accumulation at sufficient electron donor situation and then manage the stress of electron donor starvation by consumpiton of the PHB. High-throughput 16S rRNA gene sequencing analysis indicated that non-methylotrophic Halomonas campisalis (48.1 %) and Halomonas campaniensis (30.4 %) dominated in the denitratating community. Moreover the denitratation was driven by the nitrate inhibiting the nirS transcription in the Halomonas species.
authors.affiliation: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou, China.
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Lin
authors.affiliation: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou, China.
authors.forename: Jun-Jie
authors.initials: JJ
authors.lastname: Chen
authors.affiliation: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou, China.
authors.forename: Chao-Yang
authors.initials: CY
authors.lastname: Cai
authors.affiliation: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou, China.
authors.forename: Ghulam
authors.initials: G
authors.lastname: Abbas
authors.affiliation: Department of Civil and Environmental Engineering, University of Misouri, Columbia, MO, USA.
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Hu
authors.affiliation: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou, China.|Zhejiang Prov Key Lab Water Pollut Control & Envi, Zhejiang University, Hangzhou, Zhejiang, China.|MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, China.
authors.forename: He-Ping
authors.initials: HP
authors.lastname: Zhao
authors.affiliation: Department of Environmental Engineering, College of Environmental and Resource Science, Zhejiang University, Hangzhou, China. pzheng@zju.edu.cn.|Zhejiang Prov Key Lab Water Pollut Control & Envi, Zhejiang University, Hangzhou, Zhejiang, China. pzheng@zju.edu.cn.|MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, China. pzheng@zju.edu.cn.
authors.forename: Ping
authors.initials: P
authors.lastname: Zheng
mesh_terms: D000085:Acetates / Q000378:metabolism; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000254:growth & development; D001711:Biotransformation; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004579:Electron Transport; D006885:Hydroxybutyrates / Q000378:metabolism; D000432:Methanol / Q000378:metabolism*; D059013:Microbial Consortia; D009566:Nitrates / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism*; D011091:Polyesters / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D000094122:Polyhydroxybutyrates
chemical_list: D000085:Acetates; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D006885:Hydroxybutyrates; D000432:Methanol; D009566:Nitrates; D009573:Nitrites; D011091:Polyesters; D012336:RNA, Ribosomal, 16S; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates
keywords: Denitratation kinetics; Denitratator enrichment; Denitrification; Nitrite accumulation; nir gene expression