They also produce collagenases (proteases), that are capable
of destroying collagen by their hydrolytic activity.
They are alkaliphiles and therefore develop on parchments
(prepared by rubbing in chalk) and on mural paintings, in
which they destroy the paint binders, viz. casein, starch
pastes, egg white, etc. (Strzelczyk and Stachera, 1993).
They also develop on leather bookbindings that are acid
by nature or acidi;ed by air pollutants, and on paper,
where the pH ranges from 4 to 5. Astonishingly, they
also colonized the 6000 toothbrushes made of celluloid