Fungal colonization on stoneworks. Interaction fungi-powdered stone samples.
The microbial activity plays an important role in the biodegradative processes implied in stonework decay. In natural environments it is not possible to separate the damage produced by microorganisms from damage caused by physical and chemical agents. In vitro assays carried out with microbes isolated from weathered stones are required in order to understand the biological mechanisms involved in stone deterioration. We have described, as commented in the text, how fungal colonization observed on scaglia may be the result of the fine grain size of rock, whereas inhibition of growth on marble may depend on the surface characteristics of calcite grains after grinding. The extent of microbial growth clearly depends on the quantity of cations released in solution. However, fungal growth may, in turn, induce a decrease in pH, thus promoting mineral chemical attack. These observation points to selective action of fungal species in promoting weathering well evidenced by the presence of different extents of cations released in suspension from the same sample. Detailed studies are in progress in order to go into this question.
Sbaraglia
Giovanni
G
University of Perugia, Dept. of Experimental and Biochemical Sciences, Microbiology Section, Via del Giochetto, 06126 Perugia, Italy. sbara@unipg.it
Pitzurra
Lucia
L
Moroni
Beatrice
B
Nocentini
Angela
A
Vitali
Mariolina
M
Poli
Giampiero
G
Miliani
Costanza
C
Bistoni
Francesco
F
D001154:Art; D001673:Biodegradation, Environmental; D005658:Fungi; D055593:Geological Phenomena; D005844:Geology; D006863:Hydrogen-Ion Concentration; D010316:Particle Size; D011157:Population Dynamics