Humin Assists Reductive Acetogenesis in Absence of Other External Electron Donor

Laskar, Mahasweta; Kasai, Takuya; Awata, Takanori; Katayama, Arata

doi:10.3390/ijerph17124211

Submit to this Journal Review for this Journal Edit a Special Issue

Article Menu

...

Open AccessArticle

Humin Assists Reductive Acetogenesis in Absence of Other External Electron Donor

^1,2,

^1,2,

³ and

^1,2,*

Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan

Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya 464-8603, Japan

National Institute for Land and Infrastructure Management, Tsukuba 305-0804, Japan

Author to whom correspondence should be addressed.

Int. J. Environ. Res. Public Health 2020, 17(12), 4211; https://doi.org/10.3390/ijerph17124211

Received: 7 May 2020 / Revised: 5 June 2020 / Accepted: 7 June 2020 / Published: 12 June 2020

(This article belongs to the Section Environmental Science and Engineering)

View Full-Text Download PDF

Browse Figures

Citation Export

Abstract

The utilization of extracellular electron transfer by microorganism is highly engaging for remediation of toxic pollutants under “energy-starved” conditions. Humin, an organo-mineral complex of soil, has been instrumental as an external electron mediator for suitable electron donors in the remediative works of reductive dehalogenation, denitrification, and so forth. Here, we report, for the first time, that humin assists microbial acetogenesis as the extracellular electron donor using the electron acceptor

{CO}_{2}

. Humin was obtained from Kamajima paddy soil, Japan. The anaerobic acetogenic consortium in mineral medium containing

{CO}_{2} / {HCO}_{3}^{-}

as the inorganic carbon source used suspended humin as the energy source under mesophilic dark conditions. Retardation of acetogenesis under the

{CO}_{2}

-deficient conditions demonstrated that humin did not function as the organic carbon source but as electron donor in the

{CO}_{2}

-reducing acetogenesis. The consortium with humin also achieved anaerobic dechlorination with limited methanogenic activity. Total electron-donating capacity of humin was estimated at about 87 µeeq/g-humin. The metagenomic sequencing of 16S rRNA genes showed the predominance of Firmicutes (71.8 ± 2.5%) in the consortium, and Lachnospiraceae and Ruminococcaceae were considered as the

{CO}_{2}

-reducing acetogens in the consortium. Thus, microbial fixation of

{CO}_{2}

using humin introduces new insight to the holistic approach for sustainable treatment of contaminants in environment. View Full-Text

Keywords: humin; reductive acetogenesis; CO₂ reduction; autotrophic; dechlorination; methanogenesis

▼ Show Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Supplementary Material

Supplementary File 1:
PDF-Document (PDF, 298 KiB)

Share and Cite

MDPI and ACS Style

Laskar, M.; Kasai, T.; Awata, T.; Katayama, A. Humin Assists Reductive Acetogenesis in Absence of Other External Electron Donor. Int. J. Environ. Res. Public Health 2020, 17, 4211. https://doi.org/10.3390/ijerph17124211

AMA Style

Laskar M, Kasai T, Awata T, Katayama A. Humin Assists Reductive Acetogenesis in Absence of Other External Electron Donor. International Journal of Environmental Research and Public Health. 2020; 17(12):4211. https://doi.org/10.3390/ijerph17124211

Chicago/Turabian Style

Laskar, Mahasweta, Takuya Kasai, Takanori Awata, and Arata Katayama. 2020. "Humin Assists Reductive Acetogenesis in Absence of Other External Electron Donor" International Journal of Environmental Research and Public Health 17, no. 12: 4211. https://doi.org/10.3390/ijerph17124211

Find Other Styles

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Metrics

Abstract views Pdf views Html views

Article Menu

Humin Assists Reductive Acetogenesis in Absence of Other External Electron Donor

Abstract

Supplementary Material

Share and Cite

Article Metrics

Article Access Statistics

Article Access Map by Country/Region

Further Information

Guidelines

MDPI Initiatives

Follow MDPI