Mechanisms of indoor mold survival under moisture dynamics, a special water treatment approach within the indoor context

Haoxiang Wu, Jonathan Woon Chung Wong*

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

3 Citations (Scopus)


Mold contamination is one of the most important causes for indoor air pollution. Previous studies have indicated the feasibility of employing wet-dry cycles, a special water treatment approach in indoor environments, to control indoor mold contamination. However, the underlying mechanisms regulating the responses of indoor molds to changing moisture conditions remains to be elucidated. Here, we studied the mechanisms regulating the responses to wet-dry cycles (termed as moisture dynamics) in Aspergillus penicillioides, Cladosporium cladosporioides, and Aspergillus niger. First, the dormant spores of each mold species were grown to the swollen stage. Next, swollen spores were incubated at different water activity (aw) levels (0.4, 0.6 and 0.8 aw) for up to 15 days. Afterward, the viability, lipid peroxidation and antioxidant activities (both enzymatic and non-enzymatic) of treated molds were determined. Our results show that the mold species that survived better under moisture dynamics also encountered less oxidative damage and exhibited stronger antioxidant activities. Moreover, lower RH imposed severer oxidative stress to C. cladosporioides and A. niger. Pearson correlation coefficient indicate significant correlations between oxidative stress and aw of dry periods, oxidative damage and mold survival, as well as oxidative responses and mold survival. Collectively, these results imply that oxidative stress adaptation regulates the viability of A. penicillioides, C. cladosporioides, and A. niger in response to moisture dynamics. Our findings facilitate the development of novel engineering solutions for indoor air pollution.

Original languageEnglish
Article number134748
Early online date3 May 2022
Publication statusPublished - Sept 2022

Scopus Subject Areas

  • Environmental Engineering
  • Chemistry(all)
  • Environmental Chemistry
  • Pollution
  • Public Health, Environmental and Occupational Health
  • Health, Toxicology and Mutagenesis

User-Defined Keywords

  • Antioxidant responses
  • Indoor air quality
  • Indoor mold
  • Moisture dynamics
  • Oxidative stress


Dive into the research topics of 'Mechanisms of indoor mold survival under moisture dynamics, a special water treatment approach within the indoor context'. Together they form a unique fingerprint.

Cite this