Investigation of biofilm and malodour formation in commercial washing machines
Today, washing machines are an indispensable part of most households and more than 95 percent of all private households in Germany own a washing machine. When used regularly, these machines are exposed to large quantities of microorganisms from drinking water and laundry. Some of the organisms introduced into the machine while washing can attach themselves to parts of the machine and colonize them. The formation of biofilms can lead to far-reaching problems such as the formation of malodour, biocorrosion and possibly even to a health risk through the attachment and/or spread of pathogenic organisms.
The formation of malodour is a common problem in washing machines, the cause of which has not yet been fully understood. For sustainability reasons, washing machines today are often operated with lower water consumption, lower temperatures and with mild detergents, often without bleach. These conditions can promote the survival and attachment of microorganisms in the washing machine. During the washing process, microorganisms, soilings and human cells are removed from the textiles using the detergents and enzymes contained in the detergent. These can be metabolized by attached microorganisms. The microorganisms that are selected by these conditions for growth on components in the washing machine are currently the subject of research. The metabolic processes involved in the breakdown of the numerous substances released during the washing process could also be the origin of malodour formation in washing machines.
One of the possible odour producers is Moraxella osloensis. This organism which belongs to the natural skin microbiome is of particular relevance as it may lead to infections in isolated cases.
The study of this organism in particular and its role in the washing machine habitat will contribute to a better understanding of the role washing machines can play in the spread of infectious diseases. This project aims to study the underlying mechanisms for odour formation by this strain and develop possible countermeasures.