Biotechnological potential of microorganisms from landfill leachate: isolation, antibiotic resistance and leachate discoloration

Abstract

Disposal of municipal solid waste (MSW) can be considered a risk to human health representing a great environmental problem in several countries. MSW landfills are a significant source of toxic elements in the environment. Microorganisms able to thriving in leachate wastewater may exhibit metabolic machinery to synthesize a wide range of enzymes able to degrade and/or discolor toxic compounds from leachate. The use of non-pathogenic microbial cells for human health, recovered from leachate for biotechnological application, can be considered a promising approach in bioremediation processes of toxic compounds found in these environments. The present work aimed to the isolation, antibiotic resistance evaluation and leachate discoloration by microorganisms isolated from landfill leachate of Foz do Iguaçu. Forty bacteria and fifteen filamentous fungi were isolated. From these, six bacterial showed resistance at least one tested antibiotic, while six fungal isolates showed resistance to the antimycotic nystatin. CCMIBA_4L (unidentified bacteria) and Paecilomyces sp. CCMIBA_5N, were able to discolor 19.15% and 25.26% of the leachate, respectively. The results of the present work encourage future studies to characterize the enzymes involved in the discoloration and degradation of the leachate. The findings demonstrated the potential for the use of microorganisms from landfill leachate as bioremediation tools.

Risks of Antibiotic Resistance Dissemination by Leachates from Municipal Landfills of Different Ages

“…Landfills represent a significant source of toxic substances in the environment [22]. In our study, an emphasis was placed on two large groups of micropollutants, i.e., PFAS and PC, as they are known to concentrate in leachates [23,24].…”

“…Landfill leachate is regarded as a significant point source of pollutants that may pose a hazard to the environment, particularly to surface and groundwater. In the context of AMR dissemination risks, recent studies have characterized landfill leachates in terms of microbial community structure [12], viral abundance and related bacterial hosts [21], AMR abundance [22], the concentration of micropollutants (e.g., PC and PFAS) [23][24][25][26], seasonal variations [27], and a comparison between different landfills [28]. Nevertheless, more research is needed to evaluate the potential risks of AMR dissemination from landfills in order to reveal common trends and specific differences regarding local landfills.…”

Global Situation of Bioremediation of Leachate-Contaminated Soils by Treatment with Microorganisms: A Systematic Review

“…As discussed in this review, soil contamination by leachate is a major problem worldwide [85,96,97]. Leachate is a toxic liquid that seeps through waste in landfills and other waste disposal facilities and can contaminate nearby soil and groundwater [95].…”

Beta-Lactam-Resistant Enterobacterales Isolated from Landfill Leachates

“…According to the “One Health” approach, there is a connection between human, animal and environmental health, and it indicates that one of the most relevant areas of work is bacterial resistance to antibiotics [ 7 ]. Precisely, leachates can cause problems in human, animal and environmental health because they are known to contain numerous antibiotics, antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) [ 8 , 9 , 10 , 11 ], as reported by Wu et al, who detected twenty (20) antibiotics and six (6) resistance genes ( sul 1, sul 2, tet Q, tet M, erm B and mef A) in leachates from a landfill in Shanghai, China [ 12 ]. These genes were also reported by Liu et al in leachates from Zhejiang Province, China [ 13 ].…”