Fungal Growth on Samples of Paper Inhibition by New Antifungals
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English Slovak |
| ISSN: | ISSN 0034-5806 |
| Online Access: | http://www.viks.sk/chk/res_2_99_97_107.doc |
| Abstract: | Summaries. The fungal growth on paper samples of different chemical composition due to some paper deteriorative fungi (Aspergillus lerreus, Chaetomium elalum, Stachybotrys aim and Penicillium chrysogenum) is reported. All the tested samples, stored at high relative humidity, show low resistance to fungal attack and allow the fungal growth. The addition of some new synthesized compounds to the different samples of paper inhibits the fungal growth of all the paper deteriorative fungi tested. Conclusion. The laws concerning common paper-making processes tend to underestimate the role of fungi and other micro-organisms in paper deterioration. As a matter of fact, high resistance to abiotic deteriorative agents is usually considered the most important feature of paper. Thus, biocides are commonly used as "control additives" during the manufacturing processes, but they are hardly retained on the final product17. On the contrary, not only are fungi dangerous deteriorative agents during the paper-making process, but also during the storage of paper material in libraries and bookcases. It is reasonable to suppose that in sample C a higher concentration of gelatin is responsible for the higher fungal growth observed. Among P.chrysogenum, C.elatum, A.teneus and S.atra, S.atra is the most efficient in colonizing paper substrates, probably due to its higher hydrolytic enzymatic activity. The alkaline treatment with internal sizing agent AKD, used in manufacture of samples B and C is usually preferred to rosin sizing process that is carried out at pH 4-6. As a matter of fact the alkaline paper-making procedure allows to minimize the hydrolytic degradation of carbohydrate moieties, usually due to traces of acidic impurities17. According to previously reported data18, it was found (Table 5) that AKD supports fungal growth and in some cases can even enhance it. It was also shown (Table 2) that differences in pH values of the rosin and alkaline sizing procedures (pH=4-6 and pH 8 respectively) do not affect the fungal growth significantly. All the new antifungals tested (some 2,4,6-trisubstituted 1,3,5-triazines, macro-cyclic structures containing 1,3,5-triazine units and modified dihydro-isocou-marines) showed inhibition effects on the growth of the tested fungi, but only the triazinic derivatives (3) and (4) completely stopped the fungal growth. Although nothing is known about the mechanism of action of (3) and (4), collected data seem to suggest that the inhibition mechanism involves a metabolic target common to all the tested fungi. The hereby reported results point out the importance of biotic factors in paper deterioration and suggest the necessity of introducing antifungals in paper manufacturing processes as "functional additives"17, which can be retained in the final product. We feel that die use of ad hoc planned preventive chemicals as antifungals could provide an important aid in preserving the cultural heritage contained in books. |
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| ISSN: | ISSN 0034-5806 |
