Aquatic ecosystems represent one of the largest reservoirs of phytoplankton accounting for most of the primary production of the Earth. The Lake Massaciuccoli located in Tuscany (Italy) is one of the largest swamps that in ancient times entirely covered the Versilia coastal plain. Despite its peculiar features, especially the eutrophic characteristics, its native microalgal consortia have never been explored up to now. In this work, we isolated and described four autochthonous microalgal strains from different sites in the lake (FB, Idr, CL_Sc, and CL_Ch); the four microalgal strains were identified within the Chlorella sorokiniana clade. We exposed them to ten of the most common or emerging environmental contaminants in order to describe their preliminary response to the tested substances: five metals (As, Fe, Ni, Cu, and Zn), two herbicides (Metolachlor and Sethoxydim), two antibiotics (Ciprofloxacin and Benzylpenicillin) and a non-steroidal anti-inflammatory drug (Ibuprofen). Physiological response of the strains highlighted intraspecific differences; strain CL_Sc was the most tolerant in presence of metals while strain Idr was the most sensitive. All strains were sensitive to sethoxydim and tolerant to metolachlor at all the tested concentrations. Strains FB and Idr were the most sensitive in presence of Ibuprofen while strain CL_Ch was the most sensitive to the highest Benzylpenicillin concentration. Resistance pattern of strain Idr somehow reflects both the phylogenetic and the geographic “isolation” from all other three strains. Finally, optical microscope observation confirmed some differences also in the microalgae morphological aspect. Overall, all the strains showed interesting responses in presence of high concentrations of the tested substances, representing putative interesting candidates for water remediation in wastewater treatment plants.
Synthetic sports surfaces are increasingly subject to standardization of athlete-surface and ball-surface interactions (playability parameters). Such standardizations have led to an increase in the level of the engineering and predictability of these surfaces, and as such may be beneficial also for natural turf. In warm and temperate climates, many natural turf sports surfaces are established with warm-season (C 4 ) turfgrass species due to their suitability to the environment in such areas. This study was aimed at evaluating the Féderation Internationale de Football Association (FIFA)-standard playing characteristics of different sports turf surfaces obtained from three commonly used C 4 turfgrass species: 1) ‘Tifway 419’ hybrid bermudagrass ( Cynodon dactylon var. dactylon × C. transvaalensis ), 2) ‘Zeon’ manilagrass ( Zoysia matrella ), and 3) ‘Salam’ seashore paspalum ( Paspalum vaginatum ) for factors concerning leaf tissue (silica, lignin, water content) and canopy structure (shoot density, leaf architecture, stolon density, etc.). Results showed that surfaces of different C 4 turfgrass species generate different playability parameters, with seashore paspalum being a harder faster surface, manilagrass being a softer slower surface, and hybrid bermudagrass showing intermediate characteristics. These playing quality results were associated with certain specific canopy biometrical/morphological parameters such as shoot density, horizontal stem density (HSD), leaf section, and, to a lesser extent, to certain plant tissue compounds (lignin, silica).
Production of nonfood species is promoted to marginal, degraded lands abandoned by mainstream agriculture, where extremes of water availability (droughts and floods) have increased frequency and intensity and account for severe yield reduction. Arundo donax L., common name giant cane or giant reed, is a plant that grows spontaneously in different kinds of environments with limitation to low temperature and thus widespread in temperate and hot areas all over the world. Moreover, this perennial rhizomatous grass has been identified as a leading candidate crop for lignocellulosic feedstock in the Mediterranean environment, due to its high C3 photosynthetic capacity, positive energy balance and low agro-ecological management demand. In this study, the photosynthetic performance and growth response of A. donax to waterlogging and submergence stress following a time course, as well as their respective re-oxygenation were analyzed under reproducible and controlled environment conditions. Results of growth response showed that biomass production was strongly conditioned by the availability of oxygen. In fact, only waterlogged plants showed similar growth capacity to those under control conditions, while plants under submergence resulted in a dramatic reduction of this trait. The simultaneous measurements of both gas exchanges and chlorophyll fluorescence highlighted an alteration of both stomatal and non-stomatal photosynthetic behaviors during a short/medium period of oxygen deprivation and re-oxygenation. Photosynthetic CO2 uptake was strictly related to a combination of stomatal and mesophyll diffusional constrains, depending on the severity of the treatment and exposure time. Conditions of waterlogging and hypoxia revealed a slight growth plasticity of the species in response to prolonged stress conditions, followed by a fast recovery upon reoxygenation. Moreover, the rapid restoration of physiological functions after O2 deprivation testifies to the environmental plasticity of this species, although prolonged scarcity of O2 proved detrimental to A. donax by hampering growth and photosynthetic CO2 uptake.
Microalgal-based remediation is an ecofriendly and cost-effective system for wastewater treatment. This study evaluated the capacity of microalgae in the remediation of wastewater from cleaning process of smoked cigarette butts (CB). At laboratory scale, six strains (one from the family Scenedesmaceae, two Chlamydomonas debaryana and three Chlorella sorokiniana) were exposed to different CB wastewater dilutions to identify toxicity levels reflected in the alteration of microalgal physiological status and to determine the optimal conditions for an effective removal of contaminants. CB wastewater could impact on microalgal chlorophyll and carotenoid production in a concentration-dependent manner. Moreover, the resistance and remediation capacity did not only depend on the microalgal strain, but also on the chemical characteristics of the organic pollutants. In detail, nicotine was the most resistant pollutant to removal by the microalgae tested and its low removal correlated with the inhibition of photosynthetic pigments affecting microalgal growth. Concerning the optimal conditions for an effective bioremediation, this study demonstrated that the Chlamydomonas strain named F2 showed the best removal capacity to organic pollutants at 5% CB wastewater (corresponding to 25 butts L−1 or 5 g CB L−1) maintaining its growth and photosynthetic pigments at control levels.
