Recycling composted human feces as biofertilizer for crop production: Assessment of soil and lettuce plant tissue contamination by Escherichia coli and human adenovirus.

Autor: Ferreira FDG; Laboratory of Resource Recovery in Sanitation Systems Group - RReSSa, Department of Environmental Engineering, Federal University of Santa Catarina, Technological Center, Florianopolis 88040-610, Santa Catarina, Brazil. Electronic address: ferreira.goncalves.fernanda@posgrad.ufsc.br., Carlon P; Laboratory of Resource Recovery in Sanitation Systems Group - RReSSa, Department of Environmental Engineering, Federal University of Santa Catarina, Technological Center, Florianopolis 88040-610, Santa Catarina, Brazil., Fongaro G; Laboratory of Applied Virology, Department of Microbiology, Immunology, and Parasitology, Federal University of Santa Catarina, Biological Sciences Center, Florianopolis 88040-610, Santa Catarina, Brazil., Magri ME; Laboratory of Resource Recovery in Sanitation Systems Group - RReSSa, Department of Environmental Engineering, Federal University of Santa Catarina, Technological Center, Florianopolis 88040-610, Santa Catarina, Brazil.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2024 Jun 10; Vol. 928, pp. 172375. Date of Electronic Publication: 2024 Apr 09.
DOI: 10.1016/j.scitotenv.2024.172375
Abstrakt: Using waste from sewage systems, particularly human excreta, could save resources and increase soil fertility, contributing to nutrient management. However, because of the pathogenic content in human feces, this resource can pose health risks to farmers and consumers. Therefore, this work analyzed the behavior of the microorganisms: Escherichia coli ATCC13706 and human adenovirus (HAdV-2) in the soil and the internal part of the plant tissue during the vegetative stage after applying spiked composted human feces as biofertilizer. In a greenhouse, we simulated the application of the biofertilizer in lettuce cultivation by spiking three concentrations of E. coli (6.58, 7.31, and 8.01 log 10 CFU.g -1 ) and HAdV-2 (3.81, 3.97, and 5.92 log 10 PFU.g -1 ). As a result, we achieved faster decay in soil at higher concentrations of E. coli. We estimated linear decay rates of -0.07279, -0.09092, and -0.115 days, corresponding to T 90 s of 13.7, 11.0, and 8.6 days from higher to smaller concentrations of E. coli, respectively. The estimated periods for the inactivation of 4 logarithmic units of E. coli bacteria in soil are longer than the cultivation period of lettuce for all concentrations studied. Concerning the bacterial contamination in plants, we found E. coli in the internal part of the leaves at the highest concentration tested during the first three weeks of the experiment. Furthermore, HAdV-2 was found in roots at a stable concentration of 2-2.3 log 10 PFU.g -1 in five of the six samples analyzed. Therefore, bacterial infection could pose a risk, even if fresh greens are washed before consumption, especially for short-term cultures. Regarding viral infection, a positive result in the roots after disinfection may pose a risk to root and tubercule vegetables. These discoveries highlight the importance of conducting comprehensive evaluations of hygiene practices in incorporating organic amendments in crops, explicitly aiming to minimize the risk of post-contamination.
Competing Interests: Declaration of competing interest The authors declare that none of their known personal or financial conflicts could have possibly affected the research described in this work.
(Copyright © 2024 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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