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Bioaugmentation with methanogens cultured in a micro-aerobic microbial community for overloaded anaerobic digestion recovery.

Authors :
Hua, Binbin
Cai, Yafan
Cui, Zongjun
Wang, Xiaofen
Source :
Anaerobe. Aug2022, Vol. 76, pN.PAG-N.PAG. 1p.
Publication Year :
2022

Abstract

Anaerobic digestion (AD) is widely used for conversion of waste materials into biogas, but inhibition of methane production caused by overloading can be a major problem. The micro-aerobic microbial community MC1 was used to successfully culture methanogens, Methanosarcina acetivorans C2A and Methanosaeta thermophila NBRC 101360. The maximum 16S rRNA gene concentrations of Methanosarcina acetivorans C2A and Methanosaeta thermophila NBRC101360 were 1.06 × 106 and 1.35 × 103 copies/mL, respectively. The five key bacteria in MC1 were quantified to assess the effect of inoculation on the abundances of the bacteria in the mixed culture. The original MC1 total 16S rRNA gene concentration was 1.93 × 108 copies/mL, and the total 16S rRNA gene concentration had increased to 4.79 × 109 copies/mL on day 9 (p < 0.05). The proportions of the key strains in MC1+MST had changed by day 9. Cells were harvested and used to bioaugment and increase the pH values of the high- and medium-temperature anaerobic systems. After bioaugmentation, thermophilic AD recovered well. The cumulative amounts of gas produced were 44.78% and 28.28% higher in the MC1+MST and MC1 groups, respectively, than the sterilized control. The MC1+MST group gave better results than the chemical addition control group (CaCO 3). There was no clear effect of bioaugmentation in mesophilic AD. When compared with traditional pure culture of methanogens as inoculants, methanogen cultivation in MC1 was simple and there was no need to separate and purify the target strains. This simplified methanogenic bioaugmentation agent was useful to study the mechanism of bioaugmentation for the recovery from low pH inhibition, showing the potential for practical application. [Display omitted] • MC1 provided the necessary conditions for growth of acetoclastic methanogens. • Compared with MC1, the proportions of the key strains changed in MC1+MST. • MC1-grown methanogens accelerated the recovery of the AD process. • By augmented MC1+MST, biogas production increased by 44.78%. • MC1 provided a simple procedure for cultivating bioaugmentation seeds. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
10759964
Volume :
76
Database :
Academic Search Index
Journal :
Anaerobe
Publication Type :
Academic Journal
Accession number :
158958645
Full Text :
https://doi.org/10.1016/j.anaerobe.2022.102603