Microbial implication in the formation of jarosite crystals from the iron gall ink used in ancient manuscripts

This study investigated microbial communities associated with the alteration and crystal formation in iron gall ink on a historical manuscript. Ink and paper samples showing visible discoloration were collected under sterile conditions and subjected to DNA extraction. Bacterial 16S rRNA and fungal 28S rRNA gene regions were amplified by PCR and prepared for sequencing using the Oxford Nanopore Technologies Ligation Sequencing Kit with PCR barcoding. Sequencing was performed on a MinION Mk1B device with FLO-MIN106D (R9.4.1) flow cells.