Effect of Plasterboard Composition on Stachybotrys chartarum Growth and Biological Activity of Spores

Abstract

The effects of plasterboard composition on the growth and sporulation of Stachybotrys chartarum as well as on the inflammatory potential of the spores were studied. S. chartarum was grown on 13 modified plasterboards under saturated humidity conditions. The biomass was estimated by measuring the ergosterol content of the S. chartarum culture while the spore-induced cytotoxicity and production of nitric oxide (NO), tumor necrosis factor alpha (TNF-␣), and interleukin-6 in mouse macrophages was used to illustrate the bioactivity of spores. The ergosterol content of S. chartarum correlated with the number of spores collected from plasterboards. The growth and sporulation decreased compared to that of the reference board in those cases where (i) the liner was treated with biocide, (ii) starch was removed from the plasterboard, or (iii) desulfurization gypsum was used in the core. Spores collected from all the plasterboards were toxic to the macrophages. The biocide added to the core did not reduce the growth; in fact, the spores collected from that board evoked the highest cytotoxicity. The conventional additives used in the core had inhibitory effects on growth. Recycled plasterboards used in the core and the board lacking the starch triggered spore-induced TNF-␣ production in macrophages. In summary, this study shows that the growth of a strain of S. chartarum on plasterboard and the subsequent bioactivity of spores were affected by minor changes to the composition of the core or liners, but it could not be totally prevented without resorting to the use of biocides. However, incomplete prevention of microbial growth by biocides even increased the cytotoxic potential of the spores.

Cytosolic streaming in vegetative mycelium and aerial structures of Aspergillus niger

“…Previously, it has been shown that the age of the culture as well as environmental conditions affect properties ( e.g. viability and cytotoxicity) of fungal spores (Hallsworth & Magan 1996, Cliquet & Jackson 1999, Murtoniemi et al 2003, Cliquet & Jackson 2005). Normally, spores are collected from the whole mycelium.…”

Novel mold-resistant building materials impregnated with thermally reduced nano-silver

“…Most of the carbon source in GB for S. chartarum is therefore starch. The removal of the paper liner from the GB does not affect the fungal growth, as shown by Murtoniemiet et al …”

Fungi and paper manufacture

“…Murtoniemi et al (2003) studied the influence of composition on the growth of Stachybotrys chartarum on gypsum wall board. Wall board was made without starch in the core and liner or if the gypsum core was desulfurized showed inhibited fungal growth.…”