Can Artificial Ecosystems Enhance Local Biodiversity? The Case of a Constructed Wetland in a Mediterranean Urban Context

Constructed wetlands (CW) are considered a successful tool to treat wastewater in many countries: their success is mainly assessed observing the rate of pollution reduction, but CW can also contribute to the conservation of ecosystem services. Among the many ecosystem services provided, the biodiversity of CW has received less attention. The EcoSistema Filtro (ESF) of the Molentargius-Saline Regional Natural Park is a constructed wetland situated in Sardinia (Italy), built to filter treated wastewater, increase habitat diversity, and enhance local biodiversity. A floristic survey has been carried out yearly 1 year after the construction of the artificial ecosystem in 2004, observing the modification of the vascular flora composition in time. The flora of the ESF accounted for 54 % of the whole Regional Park’s flora; alien species amount to 12 %; taxa of conservation concern are 6 %. Comparing the data in the years, except for the biennium 2006/2007, we observed a continuous increase of species richness, together with an increase of endemics, species of conservation concern, and alien species too. Once the endemics appeared, they remained part of the flora, showing a good persistence in the artificial wetland. Included in a natural park, but trapped in a sprawling and fast growing urban context, this artificial ecosystem provides multiple uses, by preserving and enhancing biodiversity. This is particularly relevant considering that biodiversity can act as a driver of sustainable development in urban areas where most of the world’s population lives and comes into direct contact with nature

A New High-Efficiency Fertilization System from Waste Materials for Soil Protection: Material Engineering, Chemical-Physical Characterization, Antibacterial and Agronomic Performances

The development of slow-release fertilizers (SRFs) based on production residues is a promising strategy to improve nutrient use efficiency and promote circular economy practices in agriculture. In this study, a series of experimental formulations were designed and tested using pumice scraps, liquid and dried blood, and bone meal, aiming at producing sustainable and low-cost N-P-K SRFs. These were processed through mixing and granulation, both in the laboratory and on a semi-industrial scale. The formulations were evaluated through release tests in 2% citric acid solution simulating the acidic conditions of the rhizosphere, and in acetic acid to assess potential nutrient leaching under acid rain conditions. The results showed a progressive cumulative release of macronutrients (NPKs), ranging from approximately 8% at 24 h to 73% after 90 days for the most effective formulation (WBF6). Agronomic trials on lettuce confirmed the effectiveness of WBF6, resulting in significant biomass increases compared with both the untreated control and a conventional fertilizer. The use of livestock waste and minerals facilitated the development of a scalable product aligned with the principles of sustainable agriculture. The observed release behavior, combined with the simplicity of production, positions these formulations as a promising alternative to conventional slow-release fertilizers

The Sardinian Culture Collection of Algae (SCCA): Ex situ conservation of biodiversity and future technological applications

The Sardinian Culture Collection of Algae (SCCA) at Interdepartmental Center of Environmental Science and Engineering (University of Cagliari) is represented by over 100 microalgal authentic strains. Cultures derived from the original type material are maintained and assigned to Cyanophyta, Chlorophyta, Charophyta, Ochrophyta and Euglenophyta, respectively. The main characteristic of this collection is that all the strains are from Sardinia region. In fact, the primary mission of SCCA is to accomplish the isolation, identification, characterization, selection and in vitro cultivation of photosynthetic microorganisms from several habitats of interest in Sardinia. The strains in this collection will provide an extremely useful source of algal strains from Sardinia which can be exploited for laboratory experimentation and future technological applications

MOLECULAR PHYLOGENY, SYSTEMATICS, AND REVISION OF THE TYPE SPECIES OF &ITLOBOMONAS&IT, &ITL&IT. &ITFRANCE&IT (VOLVOCALES, CHLOROPHYTA) AND CLOSELY RELATED TAXA

In the present study, three new strains of the rare volvocalean green alga Lobomonas were isolated from field-collected samples, one from Sardinia (Italy) and two from Argentina, and comparatively studied. The Sardinian and one of the Argentinian strains were identified as Lobomonas francei, the type species of the genus, whereas the second Argentinian strain corresponded to L. panduriformis. Two additional nominal species of Lobomonas from culture collections (L. rostrata and L. sphaerica) were included in the analysis and shown to be morphologically and molecularly identical to the L. francei strains. The presence, number, and shapes of cell wall lobes, the diagnostic criterion of Lobomonas, were shown to be highly variable depending on the chemical composition of the culture medium used. The analyses by SEM gave evidence that the cell wall lobes in Lobomonas originate at the junctions of adjacent cell wall plates by extrusion of gelatinous material. The four L. francei strains had identical nrRNA gene sequences and differed by only one or two substitutions in the ITSI + ITS2 sequences. In the phylogenetic analyses, L francei and L panduriformis were sister taxa; however, another nominal Lobmnonas species (L. monstruosa) did not belong to this genus. Lobomonas, together with taxa designated as Vitreochlamys, Tetraspora, and Paulschulzia, formed a monophyletic group that in the combined analyses was sister to the Chlamydomonas/ Volvox-clade. Based on these results, Lobomonas was revised, the diagnosis of the type species emended, a lectotype and an epitype designated, and several taxa synonymized with the type species

First data on the use of native algal strain from Ecosistema Filtro to detect the effect of phosphate on growth inhibition

The present work is a part of report on the results of a survey of the algal flora of a constructed wetland, the Ecosistema Filtro (EFS). A freshwater microalgal species was selected and assay was performed following standard guidelines, in an attempt to evaluate the role of laboratory assessments in ecological risk assessment studies. Scenedesmus sp. was viewed to a good option for the assay because it grew well and according to control acceptability criteria. We evaluated growth estimates by comparing manual cell counting to more automated growth estimates using absorbance endpoints. Results confirm the chances to promote an integrative hazard assessment approach, combining laboratory, in situ assays, water-quality parameters

Use of cell wall degrading enzymes to improve the recovery of lipids from Chlorella sorokiniana

An enzymatic treatment with cell wall degrading enzymes aimed at improving the recovery of lipids from Chlorella sorokiniana was investigated. Six commercial enzyme preparations containing cellulase, pectinase, lysozyme and three different hemicellulases were preliminary tested. The most effective preparations were then used as basic components for the formulation of enzyme cocktails with high cell wall degrading activity. Experiments were carried out according to the mixture design methodology. Analysis of the results revealed the occurrence of both synergistic and antagonistic effects which were, respectively, attributed to the cooperative destructuring of the cell wall and to non-productive competitive adsorption phenomena. A numerical optimization procedure was used to design an optimal enzyme mixture containing β-1,4-xylanase and β-1,4-mannanase in the ratio of 61:39 (% w/w). Pretreatment of C. sorokiniana by this mixture provided a lipid extraction yield of (74.74 ± 1.02)%. For comparison, the extraction yields from the untreated and water-pretreated biomass were, respectively, equal to (36.19 ± 2.33)% and (58.36 ± 1.22)%