Microbial community dynamics during anaerobic co-digestion of corn stover and swine manure at different solid content, carbon to nitrogen ratio and effluent volumetric percentages

J Environ Sci Health A Tox Hazard Subst Environ Eng. 2020;55(9):1111-1124. doi: 10.1080/10934529.2020.1771975. Epub 2020 May 27.

Abstract

The methane production and the microbial community dynamics of thermophilic anaerobic co-digestion (AD) of corn stover, swine manure and effluent were conducted at total solid (TS) content of 5%, 10% and 15%, the carbon to nitrogen ratio (C/N) of 20, 30 and 40 and the effluent volumetric percentage (EVP) of 20%, 40% and 60%. For batches with 5% TS, the highest methane yield of 238.5-283.1 mL g-1 volatile solid (VS) and the specific methane productivity of 138.5-152.2 mL g-1 initial VS were obtained at the C/N ratios of 20 and 30. For the mixtures with 10% and 15% TS, the highest methane yield was 341.9 mL g-1 VS and 351.2 mL g-1 VS, respectively, when the C/N ratio of 20% and 60% EVP conditions were maintained. Co-digestion of swine manure with corn stover caused an obvious shift in microbial population, in which the archaeal population changed from 0.3% to 2.8% and the bacterial community changed from 97.2% to 99.7%. The experimental batches with the highest relative abundance of the archaeal population (2.00% of total microbial population for 5% TS, 1.74% for 10% TS and 2.76% for 15% TS) had the highest rate of methanogenesis subsequently enhancing methane production (283.08 mL g-1 VS for 5% TS, 341.91 mL g-1 VS for 10% TS and 351.23 mL g-1 VS for 15% TS). The results of microbiome analysis enabled understanding the key populations in biomethane generation.

Keywords: 16S metagenomic sequencing; Anaerobic co-digestion; anaerobic microbial community; corn stover; swine manure.

MeSH terms

  • Anaerobiosis
  • Animals
  • Archaea / growth & development
  • Bacteria, Anaerobic / growth & development
  • Biofuels / analysis
  • Bioreactors / microbiology*
  • Carbon / analysis
  • Manure / analysis*
  • Methane / biosynthesis*
  • Microbiota*
  • Models, Theoretical
  • Nitrogen / analysis
  • Solid Waste / analysis*
  • Swine
  • Zea mays / chemistry*

Substances

  • Biofuels
  • Manure
  • Solid Waste
  • Carbon
  • Nitrogen
  • Methane