this effect could not be shown for isolates cultivated from the samples. However,
they were able to grow on blood agar in laboratory experiments. Blood pro-
teins and fats are provided by the mosquitos. Excrements (faecal pellets)
from arthropods, as well as bats and mice, provide large amounts of different
organic nutrients and have been shown to be heavily infested by microorgan-
isms, especially fungi. In addition, silk protein and eggs are also available as
growth substrates.
Grazing might also provide a kind of stimulatory effect on microbial growth
and deterioration after mechanical disturbances of the biofilm. However, we
have to consider that there might be a direct detrimental input of arthropods
on mural paintings as well, since grazing is not restricted to the biofilm but
may destroy the painting or plaster directly.
As in other terrestrial habitats, microbes and especially fungi may act as sym-
bionts, parasites and decomposers in the ecosystem of the wall painting. The pos-
sible ecological connections can be summarised as follows: (i) decomposition
of accumulated organic matter, including dead insect bodies mainly by sapro-
phytic fungi, (ii) parasitism on living arthropods resulting in their death and
thereby making organic matter available for saprophytes, and (iii) transport
of surviving microbes during grazing for nutrition by arthropods.
It is only very recently that other aspects, such as health risks to human beings,
have been considered. Possible allergic reactions of atopic people in indoor
environments, which are heavily infected with fungi, are known from other
fields of interest but have also been discussed in the context of the initial
opening of a Pyramid (“Der Fluch des Pharaos” – the curse of the Pharaohs).
The intensive, prolonged and direct contact of a restorer working on site,
254 Chapter 10
Figure 7SEM of sample from Kodersdorf, Germany, mosquito body now heavily infested by
fungi (seen as filaments)