Abstract--Surface sediments of the Guanabara Bay (Rio de Janeiro, Brazil) were analyzed by a sequential extraction procedure for Cd, Cr, Cu, Pb, Zn, Mn and Fe, determining their distribution among five geochemical phases and in the nitric acid extractable phase. Bioavailable phases and non-bioavailable phases have been determined in six transects in the bay to define the significant level of pollution due to sediment meLal contamination. A multiple correlation showed limited responsibility of Mn and Fe oxides and humic acids in the adsorption process, which allowed discrimination among the different processes and suggested the strong influence of the hydrogen sulfide present in the highly reduced bay bottom environment. The authors suggest the need to avoid disturbing bottom sediment by dredging or by artificial bottom aeration which could result in a rapid worsening of the environment due to the accelerated formation of more soluble oxygenated metal compounds making the toxic metals much more available to the benthic fauna and to the bay biota in general. © 1997 Elsevier Science Ltd

a b s t r a c tThe use of Compactus shelves by libraries and archives is a good solution to optimize the storage space and prevent dust deposits on books. However, they are probably the cause of severe cases of fungal colonization in historical library materials. A typical phenomenon occurs as a spread of white mycelial growth forming scattered spots, mainly on volumes with leather or fabric bindings. Recent studies have identified the xerophilic fungus Eurotium halophilicum (anamorph Aspergillus halophilicus) as responsible for this kind of contamination. A similar situation was found inside the Library of Humanities (BAUM), at Ca' Foscari University, Venice (Italy). Various sampling methods, including cotton swabs and adhesive tape, were adopted to isolate fungi from books and a set of aerobiological analyses was performed to characterize the environment of the repository. The presence of E. halophilicum on both books and in the indoor air was confirmed by direct observation of adhesive tape samples, microscopic observations and molecular methods. Moreover, Aspergillus creber and Aspergillus protuberus belonging to the revised group Aspergillus section Versicolores, were also isolated for the first time in Italian conservation environments.

The secondary metabolite production of several fungal strains of Aspergillus creber, Aspergillus jensenii, Aspergillus penicillioides, Aspergillus protuberus, Aspergillus vitricola, Cladosporium cladosporioides, Eurotium chevalieri, Eurotium halophilicum, Penicillium brevicompactum and Penicillium chrysogenum were characterised by liquid chromatography tamdem mass spectometry. All fungi were isolated from both air and book covers as well as from settled dust from a contaminated library in Venice (Italy). For A. creber and A. jensenii, we identified sterigmatocystin, methoxysterigmatocystin, versicolorin A and related precursors/side metabolites from the biosynthetic pathways. Deoxybrevianamid E, neoechinulin A, pseurotin A and D, and rugulusovin were principally detected from the strains of E. halophilicum, an emerging fungal species implicated in book contaminations in specific indoor niches. The analysis of settled dust showed a wide range of toxic or bioactive fungal metabolites. Forty-five different metabolites were identified in different concentrations; in particular, high amounts of asperglaucide, alamethicin, andrastin A, terrecyclic acid and neoechinulin A were detected. Also one bacterial metabolite, chloramphenicole was detected. This study increases the knowledge about metabolite production of several fungal species, as well as on the indoor presence of fungi that are not detected by aerobiological sampling. These results emphasise how routine dusting operations are necessary and essential in order to prevent further microbiological developments in library environments.

No abstract

No abstract