title: Effect of volatile fatty acids in anaerobic conditions on viability of helminth ova (Ascaris suum) in sanitization of municipal sludge.
abstract: The present work aimed at evaluating the effect of four different mixtures of diverse volatile fatty acids (VFAs) on the viability of helminth ova (Ascaris suum), under mesophilic (35°C) anaerobic conditions and at different incubation times, in order to reproduce the process of two-phase anaerobic digestion. The mixtures of VFAs contained acetic, propionic, butyric, valeric, and isovaleric acids, used at concentrations normally found in acidogenic anaerobic digesters. The four treatments all showed a reduction in Ascaris suum ova viability, among which Treatment III (4.2 g-acetic acid L-1+  2.2 g-propionic acid L-1+ 0.6 g-valeric acid L-1+ 0.6 g-isovaleric acid L-1) resulted the most efficient. We found that the full effect of VFAs on the viability loss of Ascaris suum ova in mesophilic conditions requires a minimum incubation time of 3 days. The highest efficiency in the loss of viability was observed with Treatment III and 4-day incubation. Interestingly, the proportion of acetic acid was three times as much in this treatment than in the other ones and resulted in an effect in a minimum time of 3 days. The mesophilic condition, however, was not sufficient to induce a complete loss of viability.
authors: a Departamento de Ecología y Recursos Naturales, Facultad de Ciencias , Universidad Nacional Autónoma de México, Ciudad Universitaria , México City , México.
authors: Marcelo
authors: http://orcid.org/0000-0002-8357-2674
authors: M
authors: Rojas-Oropeza
authors: b Instituto de Ingeniería - Universidad Nacional Autónoma de México , México City, México.
authors: Alejandro S
authors: http://orcid.org/0000-0002-9719-9049
authors: AS
authors: Hernández-Uresti
authors: c Lallemand , Montreal , QC , Canada.
authors: Luis S
authors: http://orcid.org/0000-0001-8048-9923
authors: LS
authors: Ortega-Charleston
authors: a Departamento de Ecología y Recursos Naturales, Facultad de Ciencias , Universidad Nacional Autónoma de México, Ciudad Universitaria , México City , México.
authors: Nathalie
authors: http://orcid.org/0000-0001-7949-5904
authors: N
authors: Cabirol
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D017165:Ascaris suum; D019149:Bioreactors; D005232:Fatty Acids, Volatile; D012722:Sewage
chemical_list: D005232:Fatty Acids, Volatile; D012722:Sewage
keywords: Helminth ova; sanitization; two-phase anaerobic digestion; viability; volatile fatty acids