Ourdia-Nouara Kernou: Laboratoire de Biomathématiques, Biophysique, Biochimie, et Scientométrie (L3BS), Faculté des Sciences de la Nature et de la Vie, Université de Bejaia, Bejaia 06000, Algeria. ORCID
Amine Belbahi: Department of Microbiology and Biochemistry, Faculty of Sciences, University of M'Sila, M'Sila 24000, Algeria.
Yasmine Sahraoui: Department of Biology, University M'Hamed Bougara of Boumerdès, Boumerdès 35000, Algeria.
Kenza Bedjaoui: Laboratoire de Biomathématiques, Biophysique, Biochimie, et Scientométrie (L3BS), Faculté des Sciences de la Nature et de la Vie, Université de Bejaia, Bejaia 06000, Algeria.
Kamelia Kerdouche: Laboratoire de Biomathématiques, Biophysique, Biochimie, et Scientométrie (L3BS), Faculté des Sciences de la Nature et de la Vie, Université de Bejaia, Bejaia 06000, Algeria.
Akila Amir: Laboratoire de Biomathématiques, Biophysique, Biochimie, et Scientométrie (L3BS), Faculté des Sciences de la Nature et de la Vie, Université de Bejaia, Bejaia 06000, Algeria.
Farid Dahmoune: Departement de Biologie, Faculté des Sciences de la Nature et de La Vie et des Sciences de La Terre, Université de Bouira, Bouira 1000, Algeria.
Khodir Madani: Centre de Recherche en Technologie Agroalimentaire, Route de Targua-Ouzemour, Bejaia 06000, Algeria.
Patricia Rijo: CBIOS-Centro de Investigação em Biociências e Tecnologias da Saúde, Universidade Lusófona, Campo Grande 376, 1749-028 Lisbon, Portugal. ORCID
The aim of this study is to inactivate ATCC 29212 present in dairy wastewater effluent using microwave (MW) waves and/or ultrasound waves (US). The ultrasonic bath treatment (35 kHz) had no significant effect on the reduction of the survival rate (predominant declumping effect). At 650 W of microwave treatment, the total destruction was completed at 75 s, while at 350 W a 3 log reduction was achieved. The Weibull model was fitted to the survival curves to describe the inactivation kinetics, and the effect of the combined microwave-ultrasound treatments was evaluated. The scaling parameter that was estimated from the inactivation kinetics for the microwaves combined with the ultrasound waves in pre-treatment was found to be lower than the scaling parameters obtained in post-treatment, which were in turn lower than those estimated for microwaves or ultrasound waves alone. The use of the ultrasound waves in pre-treatment was more effective than in post-treatment; a total reduction was achieved using a combination of US (30 min) followed by MW (650 W) with = 28.3 s, while 4.0 log was obtained by reversing all processes with = 34.5 s. The results from the protein assays indicate that the bacterial wall was damaged and that holes were formed from which protein leakage occurred.
