Genome-resolved metagenomics of sugarcane vinasse bacteria

Autor(es)

Cassman, Noriko A. ^[1] ; Lourenco, Kesia S. ^{[2, 1]} ; do Carmo, Janaina B. ^[3] ; Cantarella, Heitor ^[2] ; Kuramae, Eiko E. ^[1]

Afiliação do(s) autor(es)

^[1] KNAW, Netherlands Inst Ecol NIOO, Dept Microbial Ecol, Wageningen - Netherlands

^[2] Agron Inst Campinas, Soils & Environm Resources Ctr, POB 28, BR-13012970 Campinas, SP - Brazil

^[3] Univ Fed Sao Carlos, Environm Sci Dept, BR-18052780 Soro Carba, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: BIOTECHNOLOGY FOR BIOFUELS; v. 11, FEB 22 2018.
• Citações Web of Science: 7

Resumo

Background: The production of 1 L of ethanol from sugarcane generates up to 12 L of vinasse, which is a liquid waste containing an as-yet uncharacterized microbial assemblage. Most vinasse is destined for use as a fertilizer on the sugarcane fields because of the high organic and K content; however, increased N2O emissions have been observed when vinasse is co-applied with inorganic N fertilizers. Here we aimed to characterize the microbial assemblage of vinasse to determine the gene potential of vinasse microbes for contributing to negative environmental effects during fertirrigation and/or to the obstruction of bioethanol fermentation. Results: We measured chemical characteristics and extracted total DNA from six vinasse batches taken over 1.5 years from a bioethanol and sugar mill in Sao Paulo State. The vinasse microbial assemblage was characterized by low alpha diversity with 5-15 species across the six vinasses. The core genus was Lactobacillus. The top six represented bacterial genera across the samples were Lactobacillus, Megasphaera and Mitsuokella (Phylum Firmicutes, 35-97% of sample reads); Arcobacter and Alcaligenes (Phylum Proteobacteria, 0-40%); Dysgonomonas (Phylum Bacteroidetes, 0-53%); and Bifidobacterium (Phylum Actinobacteria, 0-18%). Potential genes for denitrification but not nitrification were identified in the vinasse metagenomes, with putative nirK and nosZ genes the most represented. Binning resulted in 38 large bins with between 36.0 and 99.3% completeness, and five small mobile element bins. Of the large bins, 53% could be classified at the phylum level as Firmicutes, 15% as Proteobacteria, 13% as unknown phyla, 13% as Bacteroidetes and 6% as Actinobacteria. The large bins spanned a range of potential denitrifiers; moreover, the genetic repertoires of all the large bins included the presence of genes involved in acetate, CO2, ethanol, H2O2, and lactose metabolism; for many of the large bins, genes related to the metabolism of mannitol, xylose, butyric acid, cellulose, sucrose, ``3-hydroxy{''} fatty acids and antibiotic resistance were present based on the annotations. In total, 21 vinasse bacterial draft genomes were submitted to the genome repository. Conclusions: Identification of the gene repertoires of vinasse bacteria and assemblages supported the idea that organic carbon and nitrogen present in vinasse together with microbiological variation of vinasse might lead to varying patterns of N2O emissions during fertirrigation. Furthermore, we uncovered draft genomes of novel strains of known bioethanol contaminants, as well as draft genomes unknown at the phylum level. This study will aid efforts to improve bioethanol production efficiency and sugarcane agriculture sustainability. (AU)

• Processo FAPESP: 13/50365-5 - Microbial networks in control of greenhouse gases emissions in biobased agriculture - MiniBag
• Beneficiário: Heitor Cantarella
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Regular
• Processo FAPESP: 13/12716-0 - Fluxo dos gases do efeito estufa (co2, n2o e ch4) a partir de solos com cana-de-açúcar em função da adubação com vinhaça concentrada e vinhaça não concentrada em diferentes epocas de aplicação.
• Beneficiário: Késia Silva Lourenço
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 14/24141-5 - Estudo das redes microbianas (networks) que controlam a emissão de N2O, CO2 e CH4 do solo com cana-de-açúcar
• Beneficiário: Késia Silva Lourenço
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado