Microbial structure and diversity in non-sanitary landfills and association with physicochemical parameters

Author(s)

Morita, Alice Kimie Martins ; Sakamoto, Isabel Kimiko ; Varesche, Maria Bernadete Amancio ; Wendland, Edson

• Document type: Journal article
• Source: Environmental Science and Pollution Research; v. 27, n. 32, p. 16-pg., 2020-07-15.

Abstract

This study assessed the bacterial populations in a non-sanitary landfill around Guarani Aquifer recharge zone in Brazil. Samples from two different positions (sites 1 and 2) at three different depths were evaluated, totaling six solid waste samples; two samples from an impacted stream were also collected. 16S rRNA sequencing was performed using the Ion S5TM XL platform; 3113 operational taxonomic units (OTUs) and 52 phyla were identified. Proteobacteria (37%) and Firmicutes (28%) were the most abundant phyla in the landfill, whereas Proteobacteria (similar to 50%) and Bacteroidetes (similar to 10%) were more profuse in surface water samples. Canonical correlation analysis (CCA) enabled us to clearly separate the samples according to their spatial location (site 1 or 2) or environmental matrix (surface water or solid waste samples), showing that microbiological populations are strongly associated with site-specific conditions and the kind of environmental matrix they come from. Environmental factors that mostly influenced the microbial communities were organic matter, oxidation-reduction potential, moisture, alkalinity, nitrogen (TKN), sodium, potassium, and zinc. Exiguobacterium (phylum Firmicutes) was overwhelmingly dominant at site 1 and was associated with higher concentrations of organic matter and potassium. Differently, site 2 did not present such dominant genera and was more diverse having lower concentrations of organic matter and nutrients. Distinct environments co-exist inside the same waste deposit, including zones which are representative of active and closed landfills and the occurrence of considerable physicochemical and microbiological shifts within short distances. Those shifts indicate that microbial populations are well adapted to the heterogeneity typical of urban solid waste, which is possibly beneficial to contaminant degradation. (AU)

• FAPESP's process: 15/03806-1 - Water availability and quality threats in a Guarani Aquifer System outcrop zone
• Grantee: Edson Cezar Wendland
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Thematic Grants
• FAPESP's process: 18/24615-8 - Effects of partial capping in the contaminants mobilization and microbial degradation in a closed waste deposit
• Grantee: Alice Kimie Martins Morita
• Support Opportunities: Scholarships in Brazil - Doctorate