A Comprehensive View of Microbial Communities in the Laundering Cycle Suggests a Preventive Effect of Soil Bacteria on Malodour Formation

Abstract

Microorganisms are an important factor in the wash-and-use cycle of textiles since they can cause unwanted aesthetic effects, such as malodour formation, and even pose health risks. In this regard, a comprehensive view of the microbial communities in washing machines and consideration of the microbial contamination of used textiles is needed to understand the formation of malodour and evaluate the infection risk related to laundering. So far, neither the compositions of washing machine biofilms leading to the formation of or protection against malodour have been investigated intensively, nor have microbial communities on used towels been analysed after normal use. Our results link the qualitative and quantitative analysis of microbial communities in washing machines and on used towels with the occurrence of malodour and thus not only allow for a better risk evaluation but also suggest bacterial colonizers of washing machines that might prevent malodour formation. It was shown that soil bacteria such as Rhizobium, Agrobacterium, Bosea, and Microbacterium in particular are found in non-odourous machines, and that Rhizobium species are able to prevent malodour formation in an in vitro model.

Evaluation of microbial pollution, biofilm formation, and malodor generation in household washing machines in Wuxi, China

“…The presence of malodorous compounds such as C 2 H 6 S 2 is associated with the growth of microorganisms in the washing machine. Bacteria in the washing machines, including Pseudomonas, Acinetobacter, and other identi ed species, are capable of producing foul-smelling compounds such as DMDS, DMTS, alkanes, alcohols, ketones, and benzothiazoles (Zinn et al, 2022). The presence of these compounds contributes to the unpleasant odor experienced by users.…”

Metabarcoding Analysis of Microorganisms Inside Household Washing Machines in Shanghai, China

“…The selection of washing machines was based on their conditions, usage patterns, cleaning methods, and the demographics of washing machine users. According to a 2016 survey by the Chinese Center for Disease Control and Prevention [ 1 ], bacterial contamination inside washing machines tends to increase with time, with no significant changes observed after three years. This suggests a potential influence of biofilm.…”

“…However, the very appliances designed to eliminate dirt and microbes may harbor and propagate these microorganisms. Microbial contamination in washing machines has emerged as an area of concern due to its potential impact on human health [ 1 ]. In recent years, there has been a growing focus on the hygiene conditions of washing machines.…”

Assessing Antibiotic-Resistant Genes in University Dormitory Washing Machines

“…The washing machine is a commonly used household appliance in daily life. However, numerous studies have indicated the widespread presence of harmful microorganisms in washing machines [ 1 , 2 ]. Complete water drainage after the washing cycle can be challenging, and the machines are often situated in damp environments, creating ideal conditions for microbial growth [ 3 ].…”