Volatile fatty acids as an added value from biowaste.
Emilia den Boer, Agnieszka Łukaszewska, Władysław Kluczkiewicz, Daria Lewandowska, Kevin King, Tero Reijonen, Tero Kuhmonen, Anssi Suhonen, Ari Jääskeläinen, Anneli Heitto, Reino Laatikainen, Elias Hakalehto
Author Information
Emilia den Boer: Faculty of Environmental Engineering, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland. Electronic address: emilia.denboer@pwr.edu.pl.
Władysław Kluczkiewicz: Faculty of Mechanical Engineering, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
Daria Lewandowska: Faculty of Environmental Engineering, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
Kevin King: Finnoflag Oy, P.O. Box 262, 70101 Kuopio, Finland.
Tero Reijonen: Savonia University of Applied Sciences, P.O. Box 6, FI-70201 Kuopio, Finland.
Tero Kuhmonen: Savonia University of Applied Sciences, P.O. Box 6, FI-70201 Kuopio, Finland.
Anssi Suhonen: Savonia University of Applied Sciences, P.O. Box 6, FI-70201 Kuopio, Finland.
Ari Jääskeläinen: Savonia University of Applied Sciences, P.O. Box 6, FI-70201 Kuopio, Finland.
Anneli Heitto: Finnoflag Oy, P.O. Box 262, 70101 Kuopio, Finland.
Reino Laatikainen: Department of Pharmacy, University of Eastern Finland, Kuopio, Finland.
Elias Hakalehto: Finnoflag Oy, P.O. Box 262, 70101 Kuopio, Finland; Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland; Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland.
The aim of the present work was to provide proof of concept of employing a co-culture of K. mobilis and E. coli for producing short and medium chainVolatile fatty acids (VFAs) from kitchen biowaste and potato peels. To this aim, experiments were carried out at pilot-scale installation with a bioreactor of 250L. Different feeding strategies were tested under microaerobic conditions, at pH 6.0-6.5 in order to enhance chain elongation. Acetic acid and ethanol were dominating products in the initial stages of the bioprocess, but in a relatively short time of approx. 20-22h from the process start accumulation of propionic acid took place followed by a chain elongation to butyric and valeric acids. The highest final products yield of 325mg/g TS was achieved for the substrate load of 99.1g TS/L (VS of 91.1g/L) and pH 6.5, with the productivity of 448mg/L/h. However, the highest average VFAs chain length (3.77C) was observed in the process run with the loading of 63.2g TS/L and pH 6.0. In this study, we demonstrated that the existing symbiosis of the co-culture of K. mobilis and E. coli favours formation and chain elongation of VFA, induced most likely by the enhanced ethanol formation. Our finding differs from the previous research which focus mostly on anaerobic conditions of VFAs production. The results provide good basis for further optimisation of VFAs production process.
