Cellulolytic microorganisms
The fungi and bacteria that digest cotton, linen and paper by converting the fibre itself into sugar. The damage is not staining, it is the material being eaten.
In detail
Cellulosic fibres — cotton, linen, ramie, jute and rayon — are described by the conservation guidance as the most vulnerable of all textiles to microbial attack, and the mechanism explains why. Cellulytic fungi and bacteria produce enzymes that convert the cellulose into soluble sugar, which the organism then metabolises as food. The fibre is not being marked; it is being consumed, and a decrease in the strength of the cloth follows. That distinction decides what cleaning can achieve. A mark left by growth is permanent — the guidance is explicit that growth permanently stains, leaving a darkened area, and that only radical treatments inappropriate for a historic textile would reduce it. Strength already lost is not recoverable at all. The practical consequences are preventive. Growth is noted above 50 per cent relative humidity and spreads rapidly above 80 per cent; spore activity generally begins above 24 degrees Celsius; and the organisms survive across a pH range of 4.0 to 9.0, which quietly rules out the household remedies that work by being mildly acidic or mildly alkaline. Once a population is established it alters the pH of the cloth, which can change the colour of the dyes.
What works
Machine washing is effective against Cellulolytic microorganisms Supported
Why
- Cellulolytic microorganisms is explained by Organic load
- Cellulolytic microorganisms is explained by Enzymes in cleaning
Sources for this page
Sources
Conserve O Gram 16/1: Causes, Detection and Prevention of Mold and Mildew on Textiles
National Park Service, US Department of the Interior, 1993 · Government or regulator
Relied on for: That cellulosics are the most vulnerable fibres, that cellulytic fungi and bacteria produce enzymes converting cellulose to soluble sugar metabolised as food, that growth permanently stains and decreases the strength of the cloth, that growth is noted above 50 per cent relative humidity and spreads rapidly above 80 per cent, and that the organisms survive across pH 4.0 to 9.0. (states this directly)