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Abstract In last decades environment has suffered strong and negative consequences resulted by a massive consuming fossil energy. As a result of this process, bioenergy has been intensively increased in recent years. Transportation sector has the largest impact in the use of bioenergy and bioethanol is a type of biofuel which can easily used for transports in place of traditional fossil fuels. Bioethanol production from 1st generation biomass such as corn, sugarcane, has been already commercialized but it is usually not sustainable because it could be seriously damage the food supply. For this reason scientific community has turned his interest to second generation bioethanol from specific energy crops or cultivation of biomass feedstock whose required land for cultivation cannot be used for food cultivations. The case arboreal lingo-cellulose Arundo donax is an example of the latter group. The present paper deals with a simulation method to optimize the performances of second generation bioethanol production by using Arundo donax as feedstock. The bioethanol production was analyzed by means of a life cycle assessment (LCA). The total energy consumption was calculated thanks to Monte Carlo method. The simulation of this second-generation biomass technology was optimized by considering the reuse of light components and of the energy recovery for the agriculture and industrial process. Thanks to these optimizations it was obtained an Energy Return On Investment (EROI) = 1,52 revealing that this technology may certainly be convenient from the energetic point of view. [ABSTRACT FROM AUTHOR]

Abstract: In the present study the effect of temperature, reaction time and dilute oxalic acid (OA) concentration during steam-pretreatment of Miscanthus × gigantueus has been evaluated using the combined severity factor (CS). At the highest CS glucan and lignin content in the water insoluble fraction (WIF) increased, while xylan content decreased. While glucose recovery in the water soluble fraction (WSF) was found at low concentration when mild CS were used (≤5.0 g L−1 at CS ≤ 2.17), xylose and arabinose concentrations were higher at low-mild CS (1.58–2.17) with a concentration peak at CS 2.03 (39.9 and 3.2 g L−1 for xylose and arabinose, respectively). The decrease in pentoses coincided with inhibitory formation in the WSF, namely acetic acid, furfural, HMF and phenolic compounds. Glucan conversion rose from 46.1% at CS 1.54 to 91.2% at CS 2.76. Likewise, maximum ethanol concentration was achieved at CS 2.76, corresponding to 20.2 g L−1 and a volumetric ethanol productivity of 0.28 g L−1 h−1. Negative correlations have been found between xylan vs. glucan conversion and xylan vs. ethanol production, suggesting that decreasing the xylan content in WIF increases both saccharification rate and ethanol concentration (R 2 0.91 and R 2 0.93, respectively). On the other hand, a positive correlation was found between ethanol production and glucan conversion (R 2 0.93). Fermentation of WSF by Scheffersomyces (Pichia) stipitis CBS 6054 at CS 1.54 produced 12.1 g L−1 of ethanol after 96 h incubation with a volumetric ethanol productivity of 0.13 g L−1 h−1. [Copyright &y& Elsevier]

Abstract: Biomass pretreatment is essential to overcome recalcitrance of lignocellulose for ethanol production. In the present study we pretreated giant reed (Arundo donax L.), a perennial, rhizomatous lignocellulosic grass with dilute oxalic acid. The effects of temperature (170–190 °C), acid loading (2–10% w/w) and reaction time (15–40 min) were handled as a single parameter, combined severity. We explored the change in hemicellulose, cellulose and lignin composition following pretreatment and glucan conversion after enzymatic hydrolysis of the solid residue. Two different yeast strains, Scheffersomyces (Pichia) stipitis CBS 6054, which is a native xylose and cellobiose fermenter, and Saccharomyces carlsbergensis FPL-450, which does not ferment xylose or cellobiose, were used along with commercial cellulolytic enzymes in simultaneous saccharification and fermentation (SSF). S. carlsbergensis attained a maximum ethanol concentration of 15.9 g/l after 48 h at pH 5.0, while S. stipitis, at the same condition, took 96 h to reach a similar ethanol value; increasing the pH to 6.0 reduced the S. stipitis lag phase and attained 18.0 g/l of ethanol within 72 h. [Copyright &y& Elsevier]

Abstract: Saccharum (Saccharum spontaneum L. ssp. aegyptiacum (Willd.) Hack.), is a rapidly growing, wide ranging high-yield perennial, suitable for second generation bioethanol production. This study evaluated oxalic acid as a pretreatment for bioconversion. Overall sugar yields, sugar degradation products, enzymatic glucan hydrolysis and ethanol production were studied as effects of temperature (150–190°C), reaction time (10–40min) and oxalic acid concentration 2–8% (w/w). Time and temperature were combined into a single parameter, Severity Factor (SF) [Log(R 0)], and related to oxalic acid using a response surface methodology. Maximum total sugar yield was attained at a SF of 2.93 and 6.79% (w/w) oxalic acid, while maximum formation of sugar degradation products was observed at the highest SF (4.05) and 5% (w/w) oxalic acid. These were also the conditions for maximum simultaneous saccharification and fermentation (SSF) of the residual solids. Commercial cellulases and Saccharomyces cerevisiae attained 89.9% glucan conversion and 17.8g/l ethanol. Pichia stipitis CBS 6054 fermented hemicellulosic hydrolysates from less severe conditions to ethanol with a yield of 0.35 (g e/g s). Maximal product yields were 69% of theoretical value and 90% of the SSF conversion efficiency for hydrolysate fermentation and SSF, respectively. [Copyright &y& Elsevier]

• Castor might be grown as rainfed crop in semi-arid Mediterranean environments. • Autumn or winter sowings allowed to increase phenological intervals and seed yield. • Photoperiod corrected growing degree unit equations showed the lowest variability. • Suitable areas for autumn sowings were identified in Sicily. Castor (Ricinus communis L.) is an oilseed crop holding great promise for semi-arid environments. In regions where minimum temperature during winter is high enough to allow plants to survive, it would be worth to explore the adaptability of the species by performing autumn sowings, thus enabling rainfed cropping systems. A two-year field experiment under different sowing times (from November to June) was conducted in Southern Italy using castor Hy. Hazera. Autumnal sowings extended the plant vegetative period; nevertheless, flowering was simultaneous with all sowing dates. Only with the latest spring sowing (that of June) both floral induction and seed ripening were postponed. Seed yield with January and February sowings was the highest (3.92 Mg/ha on average). Using the wide variability of temperature and photoperiod conditions of the different growing periods, thermal and photothermal sums to predict the length of the main phenological intervals were calculated using different models. Overall, the best predicting model was that using sums of thermal units from minimum temperatures > 8 °C and maximum temperatures of 30 °C minus the degrees exceeding 30 °C, multiplied by photoperiod. The model allowed to develop zonation maps predicting the latest sowing date and the earliest seed ripening date in Sicily for autumn-spring and spring-summer growing season. The zonation procedure indicates that castor can be sown in autumn in coastal areas, while spring sowings are more suited to colder inland and hilly areas of Sicily. The work might find practical application to individuate suitable Mediterranean areas to grow castor in winter sowings. [ABSTRACT FROM AUTHOR]

Tissue culture methods offer the potential for large-scale propagation of giant reed ( Arundo donax L.), a promising crop for energy biomass. In previous trials, giant reed resulted particularly suitable to in vitro culture. In this paper, with the final goal of enhancing the efficiency of in vitro production process and reducing costs, the influence of four different culture media (agar or gellan-gum solidified medium, liquid medium into a temporary immersion system-RITA ® or in a stationary state) on in vitro shoot proliferation of giant reed was evaluated. Giant reed exhibited a particular sensitivity to gelling agents during the phase of secondary shoot formation. Gellan gum, as compared to agar, improved the efficiency of in vitro culture giving more shoots with higher mean fresh and dry weight. Moreover, the cultivation of this species into a liquid medium under temporary immersion conditions or in a stationary state, was comparatively as effective as and cheaper than that into a gellan gum medium. Increasing 6-benzylaminopurine (BA) up to 4 mg l −1 also resulted in a further enhancement of secondary shoot proliferation. The good adaptability of this species to liquid medium and the high multiplication rates observed indicate the possibility to obtain from a single node at least 1200 plantlets every six multiplication cycles (about 6 months), a number 100 fold higher than that obtained yearly per plant by the conventional methods of vegetative multiplication. In open field, micropropagated plantlets guaranteed a higher number of survived plants, secondary stems and above ground biomass as compared to rhizome ones. [ABSTRACT FROM AUTHOR]

“Long storage” tomato is a crop traditionally cultivated in the Mediterranean area under no water supply, that recently has attracted the interest of breeders for its high tolerance to drought and as potential genetic source in breeding programs for water stress resistance. A collection of 28 genotypes of “long storage” tomato ( Solanum lycopersicum L.) was studied for carotenoid and polyphenol profile and content, vitamin C, and other physico-chemical traits of fruits. Tomato carotenoids and polyphenols were identified and quantified using high-performance liquid chromatography coupled with diode array detection and electrospray-mass spectrometry (HPLC/DAD/ESI-MS); nineteen different phenolic compounds and six different carotenoids, for a total of 25 markers, have been detected, quantified and used to discriminate among the different landraces to find out which could be the best candidate for a medium-to-large scale cultivation. Different statistical approaches (ANOVA, Principal Components Analysis, Cluster Analysis) have been used for data analysis. [ABSTRACT FROM AUTHOR]

Sustainable biomass production mostly relies on cultivation practices employing low external input supply. Wild germplasm might be suited for low-input techniques while providing enough output. The present study investigated four native Mediterranean perennial grasses ( Oryzopsis miliacea , Cymbopogon hirtus , Sorghum halepense , and Saccharum spontaneum L. ssp. aegyptiacum ), with an autumn and winter harvest regime in a 4-year field trial in Sicily (south of Italy). Species, cultivation year and harvest time had significant effects on whole season crop water use efficiency, energy efficiency and biomass quality. Species and cultivation year also significantly affected aboveground biomass yield and net energy yield. The total accumulated harvested yield over the 4-year experiment was the highest in Saccharum in both autumn and winter harvests (79.5 and 79.2 Mg DM ha −1 ), and the lowest in Cymbopogon (13.7 and 14.9 Mg DM ha −1 ). In both harvests, less than 20% of this total biomass was collected for all species at the first year (9.5–11.3% in Sorghum and 15.7–18.1% in Oryzopsis ). Peak biomass was reached at the third ( Saccharum and Sorghum ) or at the fourth year ( Orzyzopsis and Cymbopogon ) in autumn, and at the third year in winter harvest (all species). Water use efficiency was higher in the autumn than in the winter harvest (2.06 and 1.75 g L −1 , respectively), whilst the opposite was observed for energy efficiency (35.7 and 38.6 GJ ha −1 , respectively). Biomass structural compounds (hemicellulose, cellulose and acid detergent lignin) were higher in winter than autumn, while protein, lipid and ash contents were higher in autumn than winter. [ABSTRACT FROM AUTHOR]

The giant reed is a fast growing herbaceous non-food crop considered as eligible alternative energy source to reduce the usage of fossil fuels. Tolerance of this plant to abiotic stress has been demonstrated across a range of stressful conditions, thus allowing cultivation in marginal or poorly cultivated land in order not to compromise food security and to overcome land use controversies. In this work, we de novo sequenced, assembled and analyzed the A. donax low G34 ecotype leaf transcriptome (RNAseq analysis) subjected to severe long-term salt stress (256.67 mM NaCl corresponding to 32 dS m−1 electric conductibility). In order to shed light upon the response to high salinity of this non model plant, we analyzed clusters related to salt sensory and signaling transduction, transcription factors, hormone regulation, Reactive Oxygen Species (ROS) scavenging and osmolyte biosynthesis, all of them showing different regulation compared to untreated plants. The analysis of clusters related to ethylene biosynthesis and signaling indicated that gene transcription is modulated towards the minimization of ethylene negative effects upon plant growth. Certainly, the photosynthesis is strongly affected since genes involved in Rubisco biosynthesis and assembly are down-regulated. However, a shift towards C4 photosynthesis is likely to occur as gene regulation is aimed to activate the primary CO 2 fixation to PEP (phosphoenolpyruvate). The analysis of "carbon metabolism" category revealed that G34 ecotype under salt stress induces the expression of glycolysis and Krebs cycle related genes, this being consistent with the hypothesis that some sort of salt avoidance might be occurred in A. donax G34 low ecotype. By comparing our results with findings obtained with other giant reed ecotype, we identified several differences in the response to salt that are in accordance with the possibility that heritable phenotypic differences among clones of A. donax might be accumulated especially in ecotypes originating from distant geographical areas, despite their asexual reproduction modality. Additionally, 26,838 simple sequence repeat (SSR) markers were identified and validated. This SSR dataset definitely expands the marker catalogue of A. donax facilitating the genotypic characterization of this species. Image 1 • Salt stress induces the expression of glycolysis and Krebs cycle related genes. • Genes involved in Rubisco biosynthesis and assembly are down-regulated. • Transcription is towards the minimization of ethylene negative effects upon growth. • Heritable phenotypic differences might occur in ecotypes originating from distant areas. • The SSR number expands the marker catalogue useful for the genetic characterization. [ABSTRACT FROM AUTHOR]