Assessment of microbial diversity associated with CH 4 emission from sugarcane vinasse storage and transportation systems

• Published in: Journal of environmental management 2020-05, Vol.269, p.110748
• Main Authors: Oliveira, Bruna G, Mendes, Lucas W, Smyth, Eoghan M, Tsai, Siu M, Feigl, Brigitte J, Mackie, Roderick I
• Format: Article
• Language: English
• ISSN: 1095-8630

Sugarcane bioethanol has favorable energy and greenhouse gas balance, although the production process generates several residues including vinasse, which deserves attention because of its significant methane (CH ) emission during storage and transportation stages. Considering that CH emissions are dependent on the structure and abundance of microbial communities, we hypothesized that different vinasse transportation systems would harbor different microbial community composition, resulting in distinct CH patterns. To test this hypothesis, we used high-throughput 16S rRNA sequencing with real-time PCR to evaluate the composition and abundance of microorganisms in the two main systems of vinasse storage and transportation (i.e. open channels and tanks systems) in Brazil. Our results showed higher microbial diversity and CH emissions in channel system, especially in the uncoated section. Significant differences in microbial community structure, diversity, and abundance between the uncoated/coated open channel and tanks indicated a clear selection at taxonomic and functional levels, especially in relation to CH production. These responses included higher methanogens diversity in the uncoated section of the channel and are in agreement with the methanogen abundance determined by mcrA and mba genes copy number (1.5 × 10 and 4.3 × 10 ) and subsequent positive correlation with CH emissions (R  = 0.8). The most representative methanogen genus across the samples was Methanobrevibacter. The results observed herein shows that the use of the coating in the bottom of channels and tanks prevent the growth and development of a methanogen-related community. We concluded that the improvements in vinasse storage and transportation systems would significantly change the microbial community and reduce CH emissions, thereby making bioethanol a greener biofuel.