Microbial Colonization, Biofilm Formation, and Malodour of Washing Machine Surfaces and Fabrics and the Evolution of Detergents in Response to Consumer Demands and Environmental Concerns.

Bacterial attachment and biofilm formation are associated with the contamination and fouling at several locations in a washing machine, which is a particularly complex environment made from a range of metal, polymer, and rubber components. Microorganisms also adhere to different types of clothing fibres during the laundering process as well as a range of sweat, skin particles, and other components. This can result in fouling of both washing machine surfaces and clothes and the production of malodours. This review gives an introduction into washing machine use and surfaces and discusses how biofilm production confers survival properties to the microorganisms. Microbial growth on washing machines and textiles is also discussed, as is their potential to produce volatiles. Changes in consumer attitudes with an emphasis on laundering and an overview regarding changes that have occurred in laundry habits are reviewed. Since it has been suggested that such changes have increased the risk of microorganisms surviving the laundering process, an understanding of the interactions of the microorganisms with the surface components alongside the production of sustainable detergents to meet consumer demands are needed to enhance the efficacy of new antimicrobial cleaning agents in these complex and dynamic environments.