Enzymatic laundry for old clothes: immobilized alpha-amylase from Bacillus sp. for the biocleaning of an ancient Coptic tunic

The classification and conservation of ancient artworks (belonging to collections) is of important cultural, historical, and economic concern. However, ancient textiles often display structural damage that renders them fragile and unsuitable for exhibition. One of the most common types of damage is linked to erroneous restoration treatments, among which the application of glues to consolidate cuts. Harsh strategies, such as mechanical or chemical treatments, are not suitable since they can cause further impairment of the fabric, whereas mild approaches, like wet cleaning, are often ineffective, as also demonstrated by the present study. Here, we have explored the possibility of using gellan-immobilized enzymes of bacterial origin (Bacillus alpha-amylase) to obtain a satisfactory starch removal from a damaged archaeological tunic-shroud from the Turin Egyptian Museum (Italy), without altering the original yarns or textile fibers. This method, already applied to clean casein-damaged wall paintings, as well as cotton, silk, and linen fabrics, has proved to be optimal for the treatment of a wool burial shroud and to be able to definitively solve fragile textile restoration problems. Moreover, efforts have been made to obtain insights into the artwork: a multidisciplinary approach has allowed to obtain a correct chronological attribution (radiocarbon dating) and fabric fiber characterization (SEM-EDX) as well as shed light on the colored parts and dark stains (FORS+IRFC and XRF). Finally, the evaluation of the type of glue, by Fourier transform infrared spectroscopy, has suggested the best enzyme for glue removal. These results have demonstrated that a mild bio-based approach is a successful tool for the treatment of archaeological textiles in critical conditions.     

Transport,anoxia and end-product accumulation control carbon dioxide and methane production and release in peat soils

Anaerobic respiration and methanogenesis have been found to slow-down in water saturated peat soils with accumulation of metabolic end-products, i.e. dissolved inorganic carbon (DIC) and methane (CH₄), due to a lack of solute and gas transport. So far it is not well understood how solute and gas transport may control this effect. We conducted a column experiment with homogenized ombrotrophic peat over a period of 300 days at 20 °C. We specifically evaluated the effects of diffusive flux as control, downward advective water flux, intensified ebullition by conduit gas transport and diffusive oxygen supply on controlling anaerobic decomposition rates and carbon (C) turnover. To simulate advective flux, water and solutes were recirculated downward through the column after stripping of dissolved gases. We analyzed DIC and CH₄ concentrations, production rates and fluxes, gas filled porosity, oxygen profiles (O₂) and microbial C biomass over time. DIC residence time thereby served as proxy to characterize transport. A slowdown of anaerobic respiration and methanogenesis evolved with the accumulation of the end-products DIC and CH₄ and set in after 150 days. This slow-down was accompanied by a decrease in the distribution of microbial biomass C with depths. Anaerobic DIC and CH₄ production rates were fastest close to the water table and sharply slowed with depth. Accumulation of DIC and CH₄ in the homogeneous peat material throughout the column decreased decomposition constants from about 10^?5 near the surface to 10^?9 year^?1 deeper in the profile. Advective water transport extended the zone of active methanogenesis compared to a diffusive system; experimental enhancement of ebullition had little or no effect as well as strictly anoxic conditions. DIC residence time was negatively correlated to anaerobic respiration suggesting this parameter to be a predictor of anaerobic peat decomposition in peatlands. Overall, this study suggests that burial of peat and accumulation of metabolic end-products effectively slows decomposition and that this effect needs to be considered to explain peat accumulation and the response of peat mineralization rates to changes in environmental conditions.     

Peptide aptamers:The versatile role of specific protein function inhibitors in plant biotechnology

In recent years,peptide aptamers have emerged as novel molecular tools that have attracted the attention of researchers in various fields of basic and applied science,ranging from medicine to analytical chemistry.These artificial short peptides are able to specifically bind,track,and inhibit a given target molecule with high affinity,even molecules with poor immunogenicity or high toxicity,and represent a remarkable alternative to antibodies in many different applications.Their use is on the rise,driven mainly by the medical and pharmaceutical sector.Here we discuss the enormous potential of peptide aptamers in both basic and applied aspects of plant biotechnology and food safety.The different peptide aptamer selection methods available both in vivo and in vitro are introduced,and the most important possible applications in plant biotechnology are illustrated.In particular,we discuss the generation of broadbased virus resistance in crops, "reverse genetics" and aptasensors in bioassays for detecting contaminations in food and feed.Furthermore,we suggest an alternative to the transfer of peptide aptamers into plant cells via genetic transformation,based on the use of cell-penetrating peptides that overcome the limits imposed by both crop transformation and Genetically Modified Organism commercialization.     

Correlation between the presence of Gonyaulax fragilis (Dinophyceae) and the mucilage phenomena of the Emilia-Romagna coast (northern Adriatic Sea)

The formation of massive amounts of suspended mucilaginous organic matter which periodically affects the Adriatic Sea, has been regarded as a complex physico-chemical phenomenon resulting from the production of extracellular material by phytoplankton. Although the exact cause has remained obscure, the mechanism of its formation has usually been considered to be a long-term process, starting after the late winter-early spring blooms, and involving the participation of various algal species, mainly within the diatom group. In this paper we report on the results of a phytoplankton monitoring programme in northern Adriatic seawaters off the Emilia-Romagna coast of Italy which revealed the constant concomitant presence of the dinoflagellate Gonyaulax fragilis (Schütt) Kofoid and mucilaginous formations. In the early stages of the phenomenon the dinoflagellate was clearly observable by microscopic examination in the mucilage, but as the mucilage aged this alga almost completely decomposed and diatom cells increased in number and became predominant. Although characterized by a slow growth rate in culture, in natural seawater G. fragilis was observed to reach cell densities of up to 7.0×10⁶ cells l⁻¹. The results of this study lead us to propose the hypothesis that the appearance of mucilage in the water column of the Adriatic Sea is the consequence of a seasonal growth of this dinoflagellate favoured by specific environmental circumstances.     

Contents of Volume 10 (2002)

Wetlands Ecology and Management -     

Habitat-Specific Diversity of Borrelia burgdorferi Sensu Lato in Europe, Exemplified by Data from Latvia

The distribution of Borrelia burgdorferi sensu lato genospecies in questing Ixodes ricinus ticks from ecologically distinct habitats in Latvia was analyzed. A significant variation in the frequency of the genospecies across sites was observed, pointing to the importance of the host community in the ecology of Lyme borreliosis.     

Signification paléoécologique des assemblages de diatomées du Messinien dans le bassin de Melilla-Nador (Rif Nord-Oriental, Maroc)

In the Melilla-Nador basin, the diatomites represent one of the main sedimentary components of the Messinian together with reefal carbonate platforms. Two vertical sections were realised in the diatomitic levels from distal platform. Diatom assemblages are for the first time described in this basin. A total of 125 diatom species were determined: 73 centrics and 52 pennates. Significant diatom assemblages defined from the statistical analysis indicate ecological variations concerning diatomitic levels or parts of diatomitic levels. Using the data sets we propose paleoenvironmental models showing the complexity of the ecological interactions. This study point the permanence of opened marine environment, the impulse of cold waters from Atlantic origin, a general decrease in bathymetry in the Messinian marls-diatomitic series, the influence of the carbonate platform progradation and the occurrence of upwelling systems.