The chemostat metabolite spectra of alkaline mixed culture fermentation under mesophilic, thermophilic, and extreme-thermophilic conditions

Kun Dai; Fang Zhang; Yan Zhang; Raymond Jianxiong Zeng

doi:10.1016/j.biortech.2017.10.035

The chemostat metabolite spectra of alkaline mixed culture fermentation under mesophilic, thermophilic, and extreme-thermophilic conditions

Bioresour Technol. 2018 Feb:249:322-327. doi: 10.1016/j.biortech.2017.10.035. Epub 2017 Oct 10.

Authors

Kun Dai¹, Fang Zhang², Yan Zhang³, Raymond Jianxiong Zeng⁴

Affiliations

¹ Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, Hebei 066004, People's Republic of China.
² Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, Hebei 066004, People's Republic of China; CAS Key Laboratory for Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
³ CAS Key Laboratory for Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
⁴ CAS Key Laboratory for Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China. Electronic address: rzeng@ustc.edu.cn.

PMID: 29054062
DOI: 10.1016/j.biortech.2017.10.035

Abstract

Alkaline mixed culture fermentation (MCF) is a promising technology for reducing organic waste and producing biochemicals. However, chemostat metabolite spectra that are necessary for constructing a model and analyzing factors are seldom reported. In the present study, the effects of pH on the metabolites distribution in mesophilic (35 °C), thermophilic (55 °C), and extreme-thermophilic (70 °C) alkaline MCF were demonstrated. A chemical oxygen demand balance above 80% was achieved, and the main metabolites included acetate, ethanol, propionate, lactate, and formate. The yields of ethanol and formate increased as pH was increased from 7.5 to higher pH under mesophilic and thermophilic conditions, while the yields of acetate, lactate, and/or propionate decreased. The yields of ethanol, acetate, and formate increased under extreme-thermophilic conditions as pH was increased from 7.5 to 9.0, whereas lactate and hydrogen yields decreased. Low biomass yield under thermophilic and extreme-thermophilic conditions benefited higher metabolite production and minimized the accumulation of sludge.

Keywords: Alkaline; Chemostat; Metabolic spectra; Mixed culture fermentation; Thermodynamic.

MeSH terms

Archaea*
Bioreactors*
Fermentation*
Hydrogen
Hydrogen-Ion Concentration
Sewage

Substances

Sewage
Hydrogen