DP_AEM student
Centro de Engenharia Biológica (CEB)
Doctoral Program in Chemical and Biological Engineering (CEB)
António Vicente

Phd Thesis

Biodegradation of PHA-based packaging materials by soil: characterization and optimization

FTC Scholarship: PD/BD/146195/2019

Started on April 2019 - Expected end date May 2023

In this experimental plan, packaging materials formed from PHA blends will be prepared and tested for biodegradation in soil conditions. The goal of this project is to establish and optimize the best conditions of biodegradation in soil for new PHA-based packaging materials, produced from food by-products’ substrates (i.e., cheese whey and almond shells).

The overall goal contains the following specific objectives:
1 – Characterize the PHA-based packaging materials in terms of their physic-chemical properties before and after biodegradation;
2 - Determine the importance of some variables in the process of biodegradation, including temperature and moisture in soil conditions, in order to find the optimal conditions of biodegradation, using the actual standards for plastic biodegradation;
3 - Identify the microbial species involved in the biodegradation process;
4 – Isolate the best-performing microorganisms in PHA-based packaging materials’ degradation;
5 - Use cocktails of the best microorganism’s species identified, and test their effects on the biodegradation of PHA in soil;

This work will validate the evaluated PHA-based packaging materials in terms of their environmental footprint. The analysis of the biodegradation process and the influence of several factors will allow to determine the optimal conditions and possibly to reduce the degradation time to a minimum (i.e., degradation time will be the variable to optimize/minimize). The results will also allow to:
- understand the degradation kinetics throughout the process; and
- identify the most important microorganisms and understand if they can be used to further optimize the degradation process.
Furthermore, the investigation will significantly add to the knowledge-base of soil biodegradation of PHA, useful for their risk assessment, life cycle assessment and rational decision-making for their use as food packaging solutions.

Task 1 - Biodegradation of a PHA-based packaging material In the first task, a PHA-based packaging material will be submitted to biodegradation tests using soil as the inoculum source.  February 2020- February 2021

Task 2 – Finding the optimal biodegradation conditions for a PHA based material.  November 2020- January 2022

Task 3 –PHB biodegradation at optimal conditions April 2022 - January 2023

Task 4 – Bioaugmentation of the microorganisms isolated from the films surface to soil microcosms - November 2021 - March 2023

Task 5 -Thesis writing - 4 years


Host Institution: Centre of Biological Engineering - School of Engineering, University of Minho

Doctoral Program - Chemical and Biological Engineering

Advisors: Professor António Vicente; Professor Madalena Alves;

Publication and Meetings

 Full Articles in International Journals with Peer Review:

 After the begining of the doctoroal program:

Fernandes, Miguel, Andreia Salvador, Madalena M. Alves, and António A. Vicente. 2020. “Factors Affecting Polyhydroxyalkanoates Biodegradation in Soil.” Polymer Degradation and Stability 182:109408.


 Before the beginning of the doctoral program:

Amorim, J., Fernandes, M., Vasconcelos, V., and Oliva Teles, L. (2017a). Evaluation of the sensitivity spectrum of a video tracking system with zebrafish (Danio rerio) exposed to five different toxicants. Environ. Sci. Pollut. Res. 24, 16086–16096.

Amorim, J., Fernandes, M., Vasconcelos, V., and Oliva Teles, L. (2017b). Stress test of a biological early warning system with zebrafish (Danio rerio). Ecotoxicology 26, 13–21.

Amorim, J., Fernandes, M., Abreu, I., Tavares, F., and Oliva-Teles, L. (2018). Escherichia coli’s water load affects zebrafish (Danio rerio) behavior. Sci. Total Environ. 636, 767–774.

Fernandes, M., Amorim, J., Vasconcelos, V., and Teles, L.O. (2016). Resilience assessment of a biological early warning system based on the locomotor behavior of zebrafish (Danio rerio). Environ. Sci. Pollut. Res. 23, 18858–18868.

Gabriel, M.F., Felgueiras, F., Fernandes, M., Ribeiro, C., Ramos, E., Mourão, Z., and de Oliveira Fernandes, E. (2020). Assessment of indoor air conditions in households of Portuguese families with newborn children. Implementation of the HEALS IAQ checklist. Environ. Res. 182, 108966.

Oliva Teles, L., Fernandes, M., Amorim, J., and Vasconcelos, V. (2015). Video-tracking of zebrafish (Danio rerio) as a biological early warning system using two distinct artificial neural networks: Probabilistic neural network (PNN) and self-organizing map (SOM). Aquat. Toxicol. 165, 241–248.


8th Workshop of the Doctoral Program in Applied and Environmental Microbiology; February, 2020, Campus de Gualtar, University of Minho, Braga, Portugal.


Seminar of the PhD Program in Applied and Environmental Microbiology (DP_AEM) at 2nd February 2021, Virtual meeting.


Presentation in the 2nd Chemical and Biological Engineering Doctoral Symposium - September 2021

Article - Biodegradable Packaging in Quality Magazine, 2nd edition 2021. Portuguese Association for Quality

Participation in the - Usable Packaging webinar - 30 June of 2021




Communication skills (course level 2) with Dr. Ana Salgado. Campus de Gualtar, University of Minho, Braga, Portugal, June– July 2019.


Workshop on transferable skills with Dr. Cátia Marques. Campus de Gualtar, University of Minho, Braga, Portugal, 11 - 12 February 2020.