Microbes of XVI century Arrases of Krakow Royal Castle.

Sixteenth-century Arrases from the Krakow Royal Castle constitute a Polish national cultural heritage; hence, they should be under special protection. The storage of historic objects at strict temperature and humidity conditions is fundamental for their protection against microorganisms. However, sometimes active preservation must be applied to disinfect bio-contaminated objects. In this study, 39 strains of microorganisms, both fungi and bacteria, isolated from Arrases deposited in the Wawel warehouse were isolated and then identified using molecular tools. Fungal ability to colonize and degrade silk and wool laboratory samples was studied. Selected microbial strains were compared concerning their ability to affect silk fibroin using size-exclusion chromatography (SEC). The effectiveness of low-temperature helium-generated plasma in disinfecting the model wool and silk samples inoculated with selected strains was tested. The results showed that plasma, despite its high biocidal activity in the case of paper, was not effective on porous textile materials. The alternative protection mechanism, involving active packaging in the form of textiles impregnated with silver-exchanged zeolites, could be used to separate layers of rolled tapestries in the warehouse. Nevertheless, optimal temperature and humidity conditions should be strictly maintained and controlled.

Light-Induced Production of Reactive Oxygen Species by a Novel Water-Soluble Benzophenone Derivative Containing Quaternary Ammonium Groups and Its Assembly on the Protein Fiber Surface.

Developing an efficient antimicrobial surface has important significance in the field of advanced biomaterials. A novel water-soluble benzophenone tetracarboxylamine derivative containing two quaternary ammonium groups, 3,3'-[4,4'-carbonyl-diphthalimide-]-bis(N-benzyl-N,N-dimethyl-N-propyl-1-aminium)dichloride (BPTCA-N), as a photoactive antibacterial agent was designed and synthesized. The ability of BPTCA-N to generate reactive oxygen species (ROS) in solution was investigated by light-induced activity. Its antibacterial activity in a dark environment or UV exposure was tested on Staphylococcus aureus and Escherichia coli. The influences of different solvents and the pH values on the ability of BPTCA-N to generate ROS were also discussed. BPTCA-N possessed high photoactivity and efficient ROS generation ability. The generation of hydroxyl radicals could be greatly affected by addition of other solvents and H+ or OH-. For the BPTCA-N solution at a concentration of 0.2 mmol/L, the reduction of S. aureus and E. coli could all reach 99.99%. The BPTCA-N compound was assembled onto wool protein fibers. The modified protein fabrics also showed excellent photoactivity and antibacterial property against S. aureus and E. coli. For the wool fabric modified with 30 g/L of BPTCA-N, the reduction of S. aureus could reach 99.91% and that of E. coli was 91.23%. BPTCA-N had the synergistic antibacterial effect of quaternary ammonium salt and benzophenones. It has potential application in the biomedical field as highly effective antimicrobial agent or antimicrobial biomaterial.