Study on the fungicidal effect of Na2B8O13·4H2O combined with discontinuous vacuum treatment for mass sterilization on mold-infested paper

It is well-known that paper-based artifacts are vulnerable materials, which are susceptible to deterioration due to aging, acidification, mold contamination, and other forms of degradation, leading to significant damage. Of particular concern is the degradation of paper caused by mold colonization, which presents a major challenge in the preservation of cultural heritage. Furthermore, mold and their metabolites can compromise the human immune system and trigger allergic reactions, posing serious health risks to individuals involved in the conservation and handling of these materials. In this study, the mold contamination of paper archives in Shaanxi Province, China was taken as the research object, a fungicidal method was devised for eradicating fungal growth on mold-infested paper through the application of solid Na₂B₈O₁₃·4H₂O combined with discontinuous vacuum (BDV) treatment. The effectiveness of this approach was evaluated using mold-contaminated paper archives isolated from the Shaanxi Provincial Archives in China as the subject of investigation. XPS, ICPMS, and ESR analyses confirmed that the discontinuous vacuum (DV) treatment promotes the penetration of Na₂B₈O₁₃·4H₂O, so as to enhance the anti-mold effect of moldy paper. The changes in various metabolites and RNA levels were identified as the main factors of mold death, especially those related to genes in the Pentose phosphate pathway, galactose metabolism, and membrane components and transporters. This method offers a safe, efficient, and cost-effective approach for eradicating mildew on large-scale paper materials. It also explores novel possibilities for the prevention and removal of mold on paper substrates, laying a foundation for future research on the large-scale mold control of paper-based objects.