Effect of Different Light Wavelengths and Photoperiods on the Growth of Aspergillus Niger in the Indoor Environment

Hetherington E., İZMİR TUNAHAN G., Altamirano H., Barrett E.

International Conference on Moisture in Buildings, ICMB 2025, Guimarães, Portugal, 23 - 24 October 2025, vol.776 LNCE, pp.138-148, (Full Text) identifier

  • Publication Type: Conference Paper / Full Text
  • Volume: 776 LNCE
  • Doi Number: 10.1007/978-3-032-09054-6_12
  • City: Guimarães
  • Country: Portugal
  • Page Numbers: pp.138-148
  • Keywords: indoor air quality, indoor environmental quality (IEQ), light wavelength, mould growth, sustainability, water activity
  • Dokuz Eylül University Affiliated: Yes

Abstract

Water and light are key environmental cues known to regulate fungi’s metabolism and growth. This study examines how LED wavelengths and water activity could influence the growth of household mould Aspergillus niger. Cultures were grown under two different wavelengths: water activities and photoperiods. Colony diameter, spore concentration and dry cell weight were quantified. Red light promoted mycelial growth and conidia production. Blue light was found to reduce biomass and spore formation. Photoperiods tested indicated that continuous irradiation in lower water activities promotes conidial formation but results in lower biomass. Lower water activity strongly promoted biomass and conidia formation. LED lighting with tailored spectra could be explored as an economic and sustainable method to reduce mould growth in built environment applications.