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Sustained dechlorination of vinyl chloride to ethene in dehalococcoides-enriched cultures grown without addition of exogenous vitamins and at low pH

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posted on 27.05.2020, 14:04 by Luz A Puentes Jácome, Po-Hsiang Wang, Olivia Molenda, Yi Xuan Jine-Jine Li, Ahsan Islam, Elizabeth A Edwards
© 2019 American Chemical Society. Trichloroethene (TCE) bioremediation has been demonstrated at field sites using microbial cultures harboring TCE-respiring Dehalococcoides whose growth is cobalamin (vitamin B12)-dependent. Bioaugmentation cultures grown ex situ with ample exogenous vitamins and at neutral pH may become vitamin-limited or inhibited by acidic pH once injected into field sites, resulting in incomplete TCE dechlorination and accumulation of vinyl chloride (VC). Here, we report growth of the Dehalococcoides-containing bioaugmentation culture KB-1 in a TCE-amended mineral medium devoid of vitamins and in a VC-amended mineral medium at low pH (6.0 and 5.5). In these cultures, Acetobacterium, which can synthesize 5,6-dimethylbenzimidazole (DMB), the lower ligand of cobalamin, and Sporomusa are dominant acetogens. At neutral pH, Acetobacterium supports complete TCE dechlorination by Dehalococcoides at millimolar levels with a substantial increase in cobalamin (∼20-fold). Sustained dechlorination of VC to ethene was achieved at pH as low as 5.5. Below pH 5.0, dechlorination was not stimulated by DMB supplementation but was restored by raising pH to neutral. Cell-extract assays revealed that vinyl chloride reductase activity declines significantly below pH 6.0 and is undetectable below pH 5.0. This study highlights the importance of cobamide-producing populations and pH in microbial dechlorinating communities for successful bioremediation at field sites.

Funding

Genome Canada, the Ontario Genomics Institute [2009-OGI-ABC-1405]

NSERC CREATE RENEW program [180804567],

Ontario Research Fund INTEGRATE project [ORF-RE05-WR-01]

History

School

  • Aeronautical, Automotive, Chemical and Materials Engineering

Department

  • Chemical Engineering

Published in

Environmental Science & Technology

Volume

53

Issue

19

Pages

11364 - 11374

Citation

Jacome, L.A.P. ... et al., 2020. Sustained Dechlorination of Vinyl Chloride to Ethene in Dehalococcoides-Enriched Cultures Grown without Addition of Exogenous Vitamins and at Low pH. Environmental Science & Technology, 53(19), pp. 11364 - 11374.

Publisher

American Chemical Society (ACS)

Version

VoR (Version of Record)

Rights holder

© American Chemical Society

Publisher statement

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Jacome, L.A.P. ... et al., 2020. Sustained Dechlorination of Vinyl Chloride to Ethene in Dehalococcoides-Enriched Cultures Grown without Addition of Exogenous Vitamins and at Low pH. Environmental Science & Technology, 53(19), pp. 11364 - 11374 and may be found at https://doi.org/10.1021/acs.est.9b02339

Acceptance date

23/08/2019

Publication date

2019-08-23

Copyright date

2019

ISSN

0013-936X

eISSN

1520-5851

Language

en

Location

United States

Depositor

Dr Ahsan Islam Deposit date: 22 May 2020

Exports