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Several aspects of the biodeterioration of stone are reviewed, including general deterioration mechanisms, deterioration attributed to specific biological organisms, conservation case histories, and treatment options. The literature is cited with emphasis on historic monuments.

Microbiological agents, such as bacteria, actinomycetes, and fungi, degrade cellulose. The most severe deterioration in indoor environments is primarily caused by cellulolytic fungi, resulting in loss of fiber strength and actual material failure. Other microbial spoilage can occur as a result of the permanent staining from pigmentation and mycelial penetration by both cellulolytic and non-cellulolytic fungi, the latter using food sources ranging from starch sizing to surface dirt, and oils. Much has been written concerning biocidal testing against these microfungal agents from an industrial point of view; less from a conservation standpoint. This paper submits a limited review of current literature (c. 25 years) focusing on the information and its relevance for the conservator. The following topics related to cellulosic deterioration by fungal microbes are covered; 1. current theories about the mechanism of cellulolytic attack; 2. biocides which may be employed in fungal control; and 3. choice of environmental conditions as a means of static control of fungal biodegradative agents. An annotated reference list is provided.