Projektförslag för kandidatarbete inom inst. Kemi och kemiteknik och Biologi och bioteknik


Physico-chemical properties of yeast biomass


Avdelningen för Applied Chemistry

Institutionen för Chemistry and Chemical Engineering, Chalmers University of Technology




Yeasts are essential for food, feed and chemical industries. The abundance and renewable origin of yeast biomass has recently developed a new field of science of use of microbial biomass in materials engineering.[1] The readily available yeast biomass has been suggested for capturing of harmful contaminants such as heavy metals and in film and coatings for food packaging materials.[2] Yeast biomass can be made into biodegradable films via a simple procedure of washing, homogenization and casting (Figure 1). The films have moderate strength. Ultimate tensile strength about 3 MPa have been reported.[2]


The physical properties of yeast biomass and yeast biomass films have been investigated by thermal and mechanical analysis. These investigations provide information about the strength of the network that the cells form. Chemical analysis of yeast biomass has revealed it to contain several chemical functional groups such as carboxylate, amine and hydroxyl groups. [3] A few investigations have elucidated what chemical linkages take place in the yeast biomass network. For example, amide bonds that may form between carboxylic acids and amines have been detected in dried yeast biomass.[4] The mechanical and chemical properties are vital for the engineering activities but the detailed knowledge on the interactions of yeast cells is also important for their use in food and feed.




While the physical network properties of yeast biomass are widely presented in literature, investigations on the role played by the possible chemical network is still less understood. The aim of this bachelor thesis work is to reveal both the physical and chemical interactions in a specific yeast biomass and to investigate the role of physical and chemical interactions to mechanical properties of yeast biomass.


The work will contain a literature search, identification of gaps in the current research horizon and experimental work on chemical and physical characterization of a given yeast biomass. This is a highly exploratory bachelor thesis project, and we have high hopes that the findings originating from this work will form the basis for new, interdisciplinary research questions and projects.


Genomförande /Viktiga moment/teknikinnehåll 


1. Literature search on chemical composition of yeast

2. Literature search on mechanical properties of yeast biomass

3. Laboratory analysis of chemical composition of yeast biomass using FTIR and physical properties via tensile testing


Speciella förkunskapskrav: Basic knowledge in Chemistry and Material science or Microbiology


Möjlig målgrupp: We envision an interdisciplinary group of students from both the K and Bt programs


Gruppstorlek: 4-6 studenter 


Förslagsställare/kontaktperson/huvudhandledare: Tiina Nypelö, Division of Applied Chemistry

Övriga handledare: Cecilia Geijer, Division of Industrial Biotechnology



1.         Cottet, C., et al., Materials, 2020. 13(6): 1263.

2.         Delgado, J.F., et al., Innovative food science & emerging technologies, 2018. 48: 240.

3.         Padmavathy, V., P. Vasudevan, and S. Dhingra, Chemosphere, 2003. 52(10): 1807.

4.         Delgado, J.F., et al., Journal of the Science of Food and Agriculture, 2021.


Sidansvarig Publicerad: on 03 nov 2021.