Aspergillus niger is one of the most active cellulolytic fungi. The roll of drawings in the above picture is mainly infested by A. niger and Chaetomium sp. as identified from the cultures isolated from the deteriorating inner-side of the roll. This culture was maintained on potato dextrose agar slants.
Following are the digital pictures of the portions of the slides that were studied under a compound microscope.
Aspergillus niger is ubiquitous in soil and is commonly reported from indoor environments.
Cellulase production by Aspergillus niger on lignocellulosic substrates is reported in both submerged (SmF) and solid State (SSF) Fermentations. Cellulases are the group of hydrolytic enzymes Filter paperase (FPase), Carboxymethylcellulase (CMCase) and -glucosidase (BGL) and are responsible for release of sugars in the bioconversion of the paper into a variety of products which is the cause of loss of drawing along with the paper.
P.S. (post scriptum)
Aspergillus niger is included in Aspergillus subgenus Circumdati, section Nigri. The section Nigri includes 15 related black-spored species that may be confused with A. niger, including A. tubingensis, A. foetidus, A. carbonarius, and A. awamori.