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The post-treatment of biomass from phytoremediation is not yet a well-established practice due to the risk induced by the presence of Potentially Toxic Elements (PTEs). Pyrolysis is a thermochemical treatment that reduces the volume and weight of contaminated matter producing a combustible vapor phase and a solid residue (char). A key factor enhancing the economic and the environmental sustainability of biomass valorization through pyrolysis is the production of a market value char. A proper choice of the pyrolysis operating conditions should take into account the effect of final temperature on PTEs release, on the char physicochemical properties as well as on the mobility of retained PTEs. In particular, in this work the influence of both the temperature and the plant parts is discussed (branches and leaves of Populus Nigra L. and rhizomes and culms of Arundo donax L.) on the release of Cd, Pb, Cu, and Zn in the temperature range 653–873 K under steam assisted slow pyrolysis conditions. The mobility of the heavy metals retained in the chars was also studied as well as the product yields, the gas composition and char porosity. The results suggested that in presence of Cd it is necessary to operate at low-temperature (lower than 703 K) to obtain a heavy metals free vapor phase fuel, whereas in presence of one or more metals among Pb, Cu, and Zn, it is possible to conduct a pyrolytic treatment at higher temperatures, thus obtaining a char with high BET surface area and lower metals mobility.

The soil salinity increase in the Mediterranean basin is one of the consequences of the climate change. The aim of this study was to evaluate the adaptability of giant reed (Arundo donax L.) to salinity, in conditions of higher temperatures, in order to hypothesise the future use of giant reed under these conditions. The trial was carried out in pots under a permanent metal structure, open on the sides and with a clear PE on the top. Four levels of soil salinity in the range 3.3-15.5 dS m–1 were imposed. The stem number of the most stressed treatment was about 45% lower than the control and also the stem height was lower than in all other treatments. The green and yellow leaf number decreased as the soil salinity increased, and their sum was significantly lower in the two most stressed treatments. Osmotic potential of the leaf sap was not affected by salinity. Leaf water potential and stomatal conduc- conductance in the saline treatments were lower than in the control. tance Assimilation rate showed similar pattern of stomatal conductance. Intrinsic WUE remained almost stable until July and increased during August under the most stressful conditions. PSII photochemistry was not affected by soil salinity. Biomass yield was not different from the control until to soil ECe 12.0 dS m–1: only the most stressed treatment (15.5 dS m–1) caused yield losses (50%). Tolerance threshold to salinity was 11.2 dS m–1 and the relative yield losses were 11.6% per dS m–1.

Cardoon seed oil (CO), derived from the nonedible Cynara cardunculus plant, growing in marginal and contaminated soils of Mediterranean regions, was successfully epoxidized (ECO) in a fed-batch modality. The cost-effective and environmentally friendly oils have been used as bioplasticizers of poly(lactic acid) (PLA), to improve the overall properties and broaden its industrial applications as a biodegradable packaging material. Hence, physical blends and films of PLA, containing 3% by weight of CO and ECO, were prepared by melt extrusion and compression molding, and the effect of the both bioplasticizers on structural, thermal, and mechanical properties of the obtained films was investigated. Cardoon oils induced the decreasing of glass transition temperature due to PLA free volume enhancement. This effect was particularly marked in PLA–ECO film. Thermal stability of PLA was meaningfully improved upon addition of the oils, and the mechanical properties made evident the increase of PLA ductility, particularly enhanced in the PLA–ECO system, where the polymeric matrix and the oil showed stronger physical interaction and improved phase compatibility, as also revealed by spectroscopic and morphological analyses. Therefore, the plasticization action exerted by very low concentrations of epoxidized cardoon oil efficiently overcomes PLA drawbacks, thus encouraging the feasibility of its use as a bioplastic for packaging material.

With the aim to develop biocatalysts for enhanced hydrolysis of (hemi)cellulose into monosaccharides, random diversity by directed evolution was introduced in the gene coding for the endo-β-1,4-glucanase from Streptomyces sp. G12 which had been recombinantly expressed in Escherichia coli and named rCelStrep. The main objectives were therefore to set up a complete strategy for creation and automated screening of rCelStrep evolved direct mutants and to apply it to generate and screen a library of 10,000 random mutants to select the most active variants. The diversity was introduced in the gene by error-prone polymerase chain reaction. A primary qualitative screening on solid plates containing carboxymethylcellulose as the substrate allowed selecting 2200 active clones that were then subjected to a secondary quantitative screening towards AZO-CMC for the selection of 76 improved variants that were cultured in flasks and characterized. Five rCelStrep mutants exhibiting the highest hydrolytic activities than the wild-type enzyme were further characterized and applied to the bioconversion of the pretreated Arundo donax lignocellulosic biomass. It is worth of noting that one of the five tested mutants exhibited a 30% improvement in bioconversion yields compared to the wild-type enzyme, despite the absence of the carbohydrate binding module domain in this variant. Homology models of the three-dimensional structures of the catalytic and binding modules of rCelStrep were obtained and localization of mutations on these models allowed us to speculate on the structure–function relationships of the mutants. Electronic supplementary material The online version of this article (10.1186/s13568-018-0602-7) contains supplementary material, which is available to authorized users.

Cardoon is a crop well adapted to Mediterranean climatic conditions, that is able to grow also in marginal lands thus reducing competition for land with food crops. It is considered a key crop for bio-refinery since it allows to produce different interesting molecules for industrial application. From stems it is possible to obtain large amounts of cellulose, grains are a good source of oil and proteins and roots can be a source of inulin. The aim of this research has been to evaluate the productive levels of different genotypes of cardoon in two different climatic conditions of Mediterranean cropland (a site in the Vesuvius plain and a site in the internal hilly cropland). In both the sites, during 3 years (from 2012-2013 to 2014-2015), three genotypes (Altilis, Gigante e Trinaseed) were cultivated with 2 planting densities (4 and 8 plants per m2). A low input cropping system was adopted (no irrigation and 150 kg ha-1 of N supplied as ammonium nitrate). In plainy site (NA-Ac.), lignocellulosic biomass yield was 19 t ha-1 d.m. and grain yield 2.7 t ha-1 on the average of the 3 years period. In the hilly site, biomass yield was similar (20 t ha-1 d.m.) while grain yield was higher (3.9 t ha-1 on the average) as compared to the plainy site. As regards biomass composition, an increase of hemicellulose and a decrease of cellulose content was measured in the plainy site, maybe as a response of plant to the higher drought stress.

The depletion of energy resources from fossil fuels and global warming have pushed to consider the agro-energy as one of the renewable energy sources for mitigation of climate change. In this context, agro-energy based on cultivation of energy crops in marginal lands allows to reduce competition with food crops and marginal lands abandonment, producing incomes for farmers. The aim of this work is to improve the knowledge on a promising crop (Arundo donax L.) for the production of bio-energy in marginal lands. Therefore, the behaviour of this crop was evaluated in three study areas of Campania region, under different energy inputs: two levels of nitrogen fertilisation, N100 and N50 in Sant’Angelo dei Lombardi (SA) and Bellizzi (BL). In Acerra (AC) site compost fertilisation was made to verify its effect on pollutant phytoextraction. In the last year, also crop growth analysis was done in the three sites. The results showed that giant reed confirms its adaptability to low fertility soils, allowing interesting biomass yield also in marginal lands. In more fertile environments, effect of fertilisation is not significant at least in the short term. Nevertheless, nitrogen uptake (65-130 kg N ha–1), also if lower than other highyielding crops, needs to be compensated with fertilisation to avoid depletion of soil nutrient reserves and to guarantee sustainability of this cropping system. Giant reed had a positive environmental impact, due to the improvement in soil fertility (soil organic matter and nitrogen increase) and to the mitigation of climate change (C storage in the soil). In marginal soils of Southern Italy this crop confirms an increasing trend of yield during the first 3-4 years. High productivity levels of this crop are related to the extremely high duration of the vegetative period and thus of the photosynthetic activity (from March to November in the Mediterranean area). These last are well expressed by the leaf area duration index, which is more than double than other high-yielding crops such as maize (280 vs 140 days).

Bioenergy crops are well known for their ability to reduce greenhouse gas emissions and increase the soil carbon stock. Although such crops are often held to be in competition with food crops and thus raise the question of current and future food security, at the same time mitigation measures are required to tackle climate change and sustain local farming communities and crop production. However, in some cases the actions envisaged for specific pedo-climatic conditions are not always economically sustainable by farmers. In this frame, energy crops with high environmental adaptability and yields, such as giant reed ( Arundo donax L.), may represent an opportunity to improve farm incomes, making marginal areas not suitable for food production once again productive. In so doing, three of the 17 Sustainable Development Goals (SDGs) of the United Nations would be met, namely SDG 2 on food security and sustainable agriculture, SDG 7 on reliable, sustainable and modern energy, and SDG 13 on action to combat climate change and its impacts. In this work, the response of giant reed in the marginal areas of an agricultural district of southern Italy ( Destra Sele ) and expected farm incomes under climate change (2021–2050) are evaluated. The normalized water productivity index of giant reed was determined (WP; 30.1 g m − 2 ) by means of a SWAP agro-hydrological model, calibrated and validated on two years of a long-term field experiment. The model was used to estimate giant reed response (biomass yield) in marginal areas under climate change, and economic evaluation was performed to determine expected farm incomes (woodchips and chopped forage). The results show that woodchip production represents the most profitable option for farmers, yielding a gross margin 50% lower than ordinary high-input maize cultivation across the study area.

Biomasses to be used in the phytoremediation process are generally selected to match agronomic parameters and heavy metals uptake ability. A proper selection can be made greatly effective if knowledge of the properties of the residual char from pyrolysis is available to identify possible valorization routes. In this study a comparative analysis of the yields and characteristics of char obtained from slow pyrolysis of five uncontaminated biomasses ( Populus nigra , Salix alba , Fraxinus oxyphylla , Eucalyptus occidentalis and Arundo donax ) was carried out under steam atmosphere to better develop char porosity. Moreover, the dependence of the properties of solid residue on the process final temperature was studied for E. occidentalis in the temperature range of 688–967 K. The results demonstrate that, among the studied biomasses, chars from P. nigra and E. occidentalis have to be preferred for applications regulated by surface phenomena given their highest surface area (270–300 m 2 /g), whereas char from E. occidentalis is the best choice when the goal is to maximize energy recovery.

The contribution of the rhizome to productivity of fermentable sugars and the detailed composition of rhizomes were analyzed in three mature stands of Arundo donax L. cultivated in three locations of variable fertility in the South of Italy. Although the average yearly aboveground dry biomass and rhizome amount showed large and significant differences among sites, (15.3 and 2.6 Mg ha−1 year−1 of rhizomes in the most and less productive sites respectively), rhizomes of all sites had more than 30% of the dry matter (DM) as non-structural carbohydrates (NSC). Sucrose and starch were the most abundant NSC but measurable amounts of glucose, fructose, galactose and of the valuable trisaccharide raffinose were also present. The amount of NSC in rhizomes affected their content of dry mater, and water extractives. The ash content also varied significantly among cultivation sites; the highest amount was recorded in rhizomes of the most productive site (Acerra). The abundance in cell wall components of rhizomes was similar to that of published values for the above ground biomass. The present results demonstrate that NSC content in rhizomes of mature stands is a conserved trait. Hence, rhizome biomass, thanks to its quantity and high fermentable sugars content, should be considered as a relevant fraction of the A. donax crop product whose utilization can increase the productivity and the environmental fingerprint of this crop, in view of its biomass utilization in biorefinery.

The world production of epoxidized vegetable oil, mainly epoxidized soybean oil, is continuously increasing because this product can have a wide range of applications. Non-edible vegetable oils, recovered by the plants growing on marginal and polluted lands, represent a possible answer to industry versus food chain debate. Cardoon (Cynara cardunculus L.) seed oil can be considered as an interesting and sustainable alternative to edible soybean oil to make plasticizers. In this work, a comparison between different epoxidation methods of cardoon oil is depicted and argued, focusing on strong points and weaknesses for each of them. It is found that cardoon seed oil can be successfully epoxidized through feasible existing technologies, by peracids and hydrogen peroxide equally. Moreover, it is demonstrated that a “greener” cardoon oil epoxidation process is possible, by using hydrogen peroxide in the presence of commercial γ-alumina as heterogeneous solid catalyst. Practical Applications: The paper analyzes the advantages and the problems of different epoxidation methods in order to obtain a final product with high quality and answer the environmental, social, and economic sustainability requirements.

In the last few years the need to produce food with added value has fueled the search for new ingredients and health-promoting compounds. In particular, to improve the quality of bakery products with distinct nutritional properties, the identification of new raw materials, appropriate technologies, and specific microbial strains is necessary. In this study, different doughs were prepared, with 10% and 20% flour from immature wheat grain blended with type “0 America” wheat flour. Immature flour was obtained from durum wheat grains harvested 1 to 2 weeks after anthesis. Doughs were obtained by both the straight-dough and sourdough processes. Two selected exopolysaccharide-producing strains of lactic acid bacteria (LAB), Leuconostoc lactis A95 and Lactobacillus curvatus 69B2, were used as starters. Immature flour contained 2.21 g/100 g (dry weight) of fructo-oligosaccharides. Twenty percent immature flour in dough resulted in a shorter leavening time (4.23 � 0.03 h) than with the control and dough with 10% immature flour. The total titratable acidity of sourdough with 20% immature flour was higher (12.75 � 0.15 ml 0.1 N NaOH) than in the control and sourdough with 10% immature wheat flour (9.20 ml 0.1 N NaOH). Molecular analysis showed that all samples contained three LAB species identified as L. lactis , L. curvatus , and Pediococcus acidilactici . A larger amount of exopolysaccharide was found in sourdough obtained with 20% immature flour (5.33 � 0.032 g/kg), positively influencing the exopolysaccharide content of the bread prepared by the sourdough process (1.70 � 0.03 g/kg). The addition of 20% immature flour also led to a greater presence of fructo-oligosaccharides in the bread (900 mg/100 g dry weight), which improved its nutritional characteristics. While bread volume decreased as the concentration of immature wheat flour increased, its mechanical characteristics (stress at a strain of 30%) were the same in all samples obtained with different percentages of fructo-oligosaccharides. These data support the use of immature wheat grain flour, and exopolysaccaride-producing lactic acid bacteria in formulating functional prebiotic baked goods whose nutritional value can be suitably improved.

The Cynara cardunculus hemicellulose fraction was recovered from its stem and leaf biomass and converted into valuable molecules by exploiting the extracellular xylanase and beta-xylosidase activities produced by the thermophilic bacterium Geobacillus thermantarcticus. Several degradation procedures for the arabinoglucuronoxylan extract were proposed by using efficient and different enzymatic preparations, containing both or only one xylanolytic activity of G. thermantarcticus. In particular, when the xylanase and beta-xylosidase activities were used separately in hydrolysis reactions, xyloglucurono-oligosaccharides or xylose were obtained with a yield of 32% and 62.6% respectively, with reference to the hemicellulosic extract. Furthermore, the synergic action of beta-xylosidase/xylanase activities was exploited in transglycosylation processes for the production of xylo-conjugated compounds; xylosides of primary alcohols with increasing carbon chains and aromatic alcohols were produced starting from the C. cardunculus hemicellulose, which was selected as a cheap donor. When 2-phenoxyethanol was selected as an acceptor, 2-phenoxyethyl beta-xyloside, xylobioside and xylotrioside were prepared with a yield of 38.5% with respect to the hemicellulosic extract and spectroscopically characterized.

This work presents a Life Cycle Assessment (LCA) of bioethanol (EtOH) from perennial Arundo donax L. feedstock. A "cradle-to-wheel" approach was applied considering primary data for the cultivation of dedicated crops on hilly marginal lands and innovative "second generation technologies" for feedstock conversion into EtOH. The goals of the study were to: (i) quantify impacts of lignocellulosic EtOH production/use chain, (ii) identify hotspots and (iii) compare the environmental performance of different bioethanol-gasoline vehicles, E10 (10% EtOH and 90% gasoline) and E85 (85% EtOH and 15% gasoline), with a conventional gasoline passenger car. Results for E85 underlined that the feedstock production and the use phase were the prevailing contributors, whilst for E10 the gasoline production phase shared the largest part of impacts. The comparison showed that vehicles using lignocellulosic bioethanol have potentially significant benefits on global warming, ozone depletion, photochemical oxidant formation and fossil depletion in respect to conventional passenger car.

The aims of this study were to evaluate the microbial diversity of different lignocellulosic biomasses during degradation under natural conditions and to isolate, select, characterise new well-adapted bacterial strains to detect potentially improved enzyme-producing bacteria. The microbiota of biomass piles of Arundo donax, Eucalyptus camaldulensis and Populus nigra were evaluated by high-throughput sequencing. A highly complex bacterial community was found, composed of ubiquitous bacteria, with the highest representation by the Actinobacteria, Proteobacteria, Bacteroidetes and Firmicutes phyla. The abundances of the major and minor taxa retrieved during the process were determined by the selective pressure produced by the lignocellulosic plant species and degradation conditions. Moreover, cellulolytic bacteria were isolated using differential substrates and screened for cellulase, cellobiase, xylanase, pectinase and ligninase activities. Forty strains that showed multienzymatic activity were selected and identified. The highest endo-cellulase activity was seen in Promicromonospora sukumoe CE86 and Isoptericola variabilis CA84, which were able to degrade cellulose, cellobiose and xylan. Sixty-two percent of bacterial strains tested exhibited high extracellular endo-1,4-beta-glucanase activity in liquid media. These approaches show that the microbiota of lignocellulosic biomasses can be considered an important source of bacterial strains to upgrade the feasibility of lignocellulose conversion for the 'greener' technology of second-generation biofuels.

The cultivation of giant reed lignocellulosic feedstock on marginal land, appears of great interest in the Mediterranean basin, due to its high production potential under drought conditions. Starting from a three years field survey, in this paper a LCA was applied to the overall 15 years life cycle of a Mediterranean giant reed cultivation in Southern Italy, including Direct Field Emissions (DFE) and non-productive phases of cultivation. Agricultural practices performed yearly for field maintenance (FM-urea fertilization) and harvest operation (HO) shared the largest part of total burdens, nonetheless, the impact of crop establishment and final removal appeared significant. FM was strongly affected by DFE of soil biogenic N 2 O and fossil CO 2 (about 23% and 9% of total Climate change, respectively) and volatilized NH 3 (about 69%, 42% and 35% of total impact for Terrestrial acidification, Particulate matter formation and Marine eutrophication, respectively). For Marine eutrophication, also nitrate leaching in the plantation year, affected significantly the overall life cycle. Differently DFE linked to field application of K-P fertilizers for seedbed preparation (P and heavy metal emissions) and pest for final eradication (glyphosate emission), appeared more circumscribed. The study highlighted the need to carefully approach to soil carbon storage, and disclosed to be sensitive to uncertainty linked to DFE and crop yield pattern estimation.

Of the various biomass crops, one of the most promising for bioenergy or biochemical production is giant reed (Arundo donax L.): It is tolerant to a wide range of environmental stresses and can therefore be cultivated on marginal lands which cannot be used for traditional food crops. An open field experiment was carried out in a soil subjected to accelerated erosion so as to evaluate the agronomic and environmental impact of giant reed during the first 9 years of cultivation. In a low-input cropping system, the crop gave an interesting biomass yield and gross income when grown on marginal hilly lands in southern Italy affected by climatic constraints and accelerated erosion. Its cultivation had favourable effects on environmental quality, thanks to the improvement in soil fertility (soil organic matter and N increase), mitigation of climate change (C storage in the soil) and reduction in soil loss by erosion (reducing soil erodibility and increasing vegetation cover). Winter harvest was found to be more advisable because it reduced biomass moisture and N content, thus improving biomass quality (fewer problems in storage and industrial use) and cropping system sustainability (higher N return to the soil and hence less need for N fertilization).

Polysaccharidases from extremophiles are remarkable for specific action, resistance to different reaction conditions and other biotechnologically interesting features. In this article the action of crude extracts of thermophilic microorganisms (Thermotoga neapolitana, Geobacillus thermantarcticus and Thermoanaerobacterium thermostercoris) is studied using as substrate hemicellulose from one of the most interesting biomass crops, the giant reed (Arundo donax L.). This biomass can be cultivated without competition and a huge amount of rhizomes remains in the soil at the end of cropping cycle (10–15 years) representing a further source of useful molecules. Optimization of the procedure for preparation of the hemicellulose fraction from rhizomes of Arundo donax, is studied. Polysaccharidases from crude extracts of thermophilic microorganisms revealed to be suitable for total degradative action and/or production of small useful oligosaccharides from hemicelluloses from A. donax. Xylobiose and interesting tetra- and pentasaccharide are obtained by enzymatic action in different conditions. Convenient amount of raw material was processed per mg of crude enzymes. Raw hemicelluloses and pretreated material show antioxidant activity unlike isolated tetra- and pentasaccharide. The body of results suggest that rhizomes represent a useful raw material for the production of valuable industrial products, thus allowing to increase the economic efficiency of A. donax cultivation.

Two clones of white clover (Trifolium repens L.) differing in ozone tolerance were grown in southern Italy during 1997 and 1998 to study the effects of ambient ozone exposure on yield, leaf morphology and water use. Ambient ozone levels were high in both years with values exceeding the threshold for leaf injury reported in the literature. In both years ozone injury was observed on the sensitive clone (NC-S) but not on the resistant one (NC-R), and leaf and stolon dry matter production was significantly lower in NC-S than in NC-R. However, it cannot be excluded that other factors, such as high temperature, interacted with the effect of ozone on biomass production. The clones differed in morphological characteristics. Lower total leaf area in NC-S plants was due to a smaller number of leaves per plant, but the average area per leaf was higher in NC-S. Specific leaf weight and net assimilation rate were higher in the more productive clone (NC-R). Cumulative plant water use was higher in NC-R in each growth period because of the larger leaf area; by contrast, water use per unit leaf area was higher in NC-S, indicating higher leaf conductance to water vapour. The results suggest that ozone significantly reduces the yield of sensitive white clover plants under well-watered conditions, and that the difference in ozone tolerance between clover clones is related to differences in leaf morphology and water use.

Little information is available as to the real effectiveness of the phytoextraction remediation technique, since laboratory experiments are still the most common way in which this is measured. Given this, an experiment on a cadmium-polluted soil was carried out in open field conditions in Southern Italy with the aim of assessing the growth and the phytoextraction potential of giant reed (Arundo donax L). Compost fertilisation and Trichoderma harzianum A6 inoculations were used to verify the possibility of increasing the metal uptake of the crop. Biomass yield of giant reed in the first growth season (average 12.8 Mg ha –1 ) was not affected by the Cd concentration in the soil and this increased significantly with compost fertilisation (13.8 Mg ha –1 ). Both compost fertilisation and T. harzianum inoculation increased cadmium uptake and translocation in leaves. Nitrifying bacteria was shown to be a useful tool to biomonitor soil quality. These results proved the suitability of the giant reed for assisted-phytoremedation with the use of compost fertilisation and T. harzianum.

Salinization is increasingly affecting world's agricultural land causing serious yield loss and soil degradation. Understanding how we could improve crop productivity in salinized environments is therefore critical to meet the challenging goal of feeding 9.3 billion people by 2050. Our comprehension of fundamental physiological mechanisms in plant salt stress adaptation has greatly advanced over the last decades. However, many of these mechanisms have been linked to salt tolerance in simplified experimental systems whereas they have been rarely functionally proven in real agricultural contexts. In-depth analyses of specific crop-salinity interactions could reveal important aspects of plant salt stress adaptation as well as novel physiological/agronomic targets to improve salinity tolerance. These include the developmental role of root vs. shoot systems respect to water-ion homeostasis, morphological vs. metabolic contributions to stress adaptation, developmental processes vs. seasonal soil salinity evolution, residual effects of saline irrigation in non-irrigated crops, critical parameters of salt tolerance in soil-less systems and controlled environments, response to multiple stresses. Finally, beneficial effects of salinization on qualitative parameters such as stress-induced accumulation of high nutritional value secondary metabolites should be considered, also. In this short review we attempted to highlight the multifaceted nature of salinity in Mediterranean agricultural systems by summarizing most experimental activity carried out at the Department of Agricultural Engineering and Agronomy of University of Naples Federico II in the last few years.

Giant Reed (Arundo Donax L.) is one of the most interesting crop for energy production due to the high productivity in less-fertile environments too. Among all the technological options, anaerobic fermentation with oleaginous yeasts for the synthesis of lipids rep- resents the last frontier of biological conversion of ligno-cellulosic biomasses to fuels or to bio-polymers. The chemical composition of biomass (i.e. cellulose, lignin and emicellulose) is a key factor of this process.

The main route for ozone entry in plants is through the stomata. Consequently, environmental factors that may expose plants to any stress that will eventually lead to stomatal closure, will also reduce the rate of ozone entry into the plant and will possibly counteract ozone damages. In addition, several abiotic stresses activate the synthesis of antioxidant compounds, which are responsible for neutralizing toxic ozone derivatives. Due to this complex response, it is critical to assess how abiotic stresses and ozone toxicity will interactively affect plant growth and yield, especially in those areas, such as the coastal Mediterranean regions, where these types of stress and ozone exposure typically coexist. In this research we exposed tomato plants to salt stress in presence and absence of ozone to assess how salinity and ozone may interfere in terms of physiological responses and final yield. Plants grown in absence of ozone had a greater total biomass and higher yield compared to those grown in presence of ozone. Nevertheless these differences disappeared upon salinization. The reduced ozone damage in saline environment must be interpreted on relative terms, however, since salinity by itself caused a general inhibition of plant growth and yield. Based on these results, it was concluded that defining environment-specific ozone toxicity thresholds is necessary for developing reliable prediction models and/or assessing environmental safeguard levels.

Yield losses from ozone pollution can be estimated by two methods: one involves the use of sensitive (S) and resistant (R) biotypes of white clover (Trifolium repens L., cv. Regal) exposed in ambient air, the other is based on the use of open-top chambers (OTC) supplied either with charcoal-filtered (CF) or non-filtered (NF) air. In southern Italy the two methods have been compared using the clover biotypes. The aim was (1) to compare the extent of ozone-induced yield reductions estimated by the two methods, (2) to evaluate the effect of the chamber enclosure on the growth of both biotypes, and (3) to compare plant water consumption in the different environments. On the average, the yield reduction was 23% when derived from the S/R yield ratio in ambient air, and 18% obtained by the CF/NF yield ratio of the S-type, without a significant difference between the two values. The slightly lower value for the OTC-based system may be due to the lower ozone levels in NF chambers due to losses in the ventilation system. Thus, both methods yielded equivalent yield reductions of about 20% due to ozone at this Mediterranean site. However, the higher air temperature inside OTCs influenced the plant growth, and this effect was stronger in the case of the R type. Therefore, R/S yield ratios in NF chambers differed from ambient air. Also, plant water consumption was higher in OTCs than in ambient air. The results suggest that the OTC-based method enables yield loss estimates at this Mediterranean site, in spite of chamber effects on plant growth and water use.

Giant Reed (Arundo donax L.) is well known for its adaptability to different ecological conditions, growing spontaneously in different regions of Southern Europe. Due to its high biomass productivity, it is commonly used for the production of energy, paper pulp, and wooden building materials (Papazoglou et al., 2005). Giant Reed could also be a useful tool for soil bioremediation thanks to its high resistance to pollutants (Papazoglou, 2006) together with a high accumulation capability of heavy metals in plant tissues (especially in rhizomes). A field trial was established in Acerra (Southern Italy, Campania) to asses the potential productivity of Giant Reed on a soil with high concentration of heavy metals. Treatments resulted from a factorial combination of two levels of compost (treated and non treated soil) and Trichoderma (inoculated and non inoculated rhizome). Soil samples were collected at twodepths (0-20 and 20-40 cm)at transplanting and at harvest. Soil and rhizosphere samples from plots under the different treatments were sampled and the composition of total aerobic bacteria, fungi, actinobacteria and microbial groups involved in key processes of the nitrogen cycle (e.g. aerobic free-living N2-fixing bacteria and ammonia-oxidizing bacteria) was estimated and the structure of cultivable populations was assessed. Plant aboveground tissues and rhizomes were collected after one growing season. A two-way ANOVA was performed on data considering compost addiction as main factor and Trichoderma inoculation as sub-factor in a split-plot design. Means were separated by LSD test according to a p-value of 0.05. Compost addiction allowed highest biomass production (13.2 Mg ha-1 vs 11.9 Mg ha-1 DMof non fertilized plots) and consequently highest metal uptakes. No interaction between factors was found. These results show the possibility of use Giant Reed for energy production on contaminated soils allowing incomes to farmers and reducing the levels of contamination.

This study reports enzymatic hydrolysis of the biomass of the giant reed (Arundo donax L.) after ammonia fibre expansion (AFEX) pretreatment. In particular, the capacity of the arabinofuranosidase from the fungus Pleurotus ostreatus recombinantly expressed in Pichia pastoris rPoAbf, its evolved mutant rPoAbf F435Y/Y446F and the endo-cellulase from Streptomyces sp. G12 CelStrep recombinantly expressed in Escherichia coli to enhance the hydrolysis of AFEX-treated A. donax was investigated, using the corn stover as reference feedstock. The investigated enzymes were assayed using a mixture of purified cellulases (CBHI, CBHII, EGI and βG), endoxylanases (LX3, LX4) and accessory hemicellulases (LarbF and LβX) as reference enzyme mixture and substituting EGI with rCelStrep and LarbF with rPoAbf or rPoAbf F435Y/Y446F. The use of rPoAbf F435Y/Y446F in the substitution of LarbF led to improvements in sugar conversion, giving a glucan, xylan and arabinan conversion after 72 h of around 62, 63 and 80 %, respectively, similar or higher than those (44, 66 and 55 %) achieved by 72 h hydrolysis with commercial enzymes Novozymes Cellic®, Ctec3 and Htec3. The enzymes rPoAbf, rPoAbf F435Y/Y446F and rCelStrep were also investigated for their effect on hydrolysis of AFEX-pretreated A. donax by addition to commercial enzyme mixture Novozymes Cellic®, Ctec3 and Htec3, and it was shown that the addition of rPoAbf and its evolved mutant rPoAbf F435Y/Y446F enhanced both xylan and arabinan conversions, which achieved 80 % after 6 days of saccharification with rPoAbf F435Y/Y446F.