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Rugani B.,Luxembourg Institute of Science and Technology LIST | Golkowska K.,Luxembourg Institute of Science and Technology LIST | Vazquez-Rowe I.,Luxembourg Institute of Science and Technology LIST | Vazquez-Rowe I.,Catholic University of Peru | And 4 more authors.
Applied Energy

The expansion of Short Rotation Coppice (SRC) practices is mainly driven by the viability of SRC wood as an alternative to other renewable and non-renewable fuels in energy production, but also to the capacity of increasing biodiversity and the supply of ecosystem services locally. To delve into these environmental synergies and possible trade-offs, the Life Cycle Assessment method was applied to seven SRC experimental sites recently implemented in Flanders (Belgium). These have differing land use objectives and, thus, present different species proportions and plantation density. For instance, most sites are either planted with willow and poplar clones, or with a mix of the two with local tree species in order to activate temporary unused industrial lands or enhance the local ecosystem functionality. A regular 3 to 7-year rotation was simulated up to year 2033 using CO2FIX given that trees were yet to be harvested at the time of the assessment. Yields were first estimated over time: SRC systems composed by mixed species presented the highest productivity and also the best environmental performance profiles. Overall, the highest environmental impacts were due to consumption of diesel during the cyclic harvests, but also to fertilization activities. Uncertainty distribution ranges were determined for the most critical parameters and a Monte Carlo analysis was performed to obtain average impact scores with variability ranges. While replacing hardwood with wood from SRC chips was not found to be advantageous because of e.g. larger metal, fossil and ozone depletion potentials, benefits were observed for land use reduction and climate change mitigation. Due to frequent rotations, the beneficial trends for the latter seem sufficient to compensate the negative effects of the other impacts on human health and ecosystems quality. © 2015 Elsevier Ltd. Source

De Moor S.,Ghent University | Velghe F.,Organic Waste Systems | Wierinck I.,Organic Waste Systems | Michels E.,Ghent University | And 5 more authors.
Bioresource Technology

This study investigated the potential of co-digestion of grass clippings in a typical Flemish agro-digester characterized by an input of 30% manure, 30% maize silage and 40% side streams. No significant adverse effects in the microbiological functioning of the reactors were detected when part of the maize input was replaced by 10-20% grass. However at the highest dosage of grass input, dry matter content and the viscosity of the reactor content increased substantially. These parameters could be reduced again by enzyme addition in the form of MethaPlus L100. It can be concluded that co-digestion of 20% grass in an agricultural digester would not pose any problem if dry matter content and viscosity are improved by the use of an enzyme mixture. © 2013 Elsevier Ltd. Source

Pauwelyn E.,Ghent University | Huang C.-J.,Ghent University | Ongena M.,University of Liege | Leclere V.,Lille University of Science and Technology | And 5 more authors.
Molecular Plant-Microbe Interactions

Pseudomonas cichorii is the causal agent of lettuce midrib rot, characterized by a dark-brown to green-black discoloration of the midrib. Formation of necrotic lesions by several plant-pathogenic pseudomonads is associated with production of phytotoxic lipopeptides, which contribute to virulence. Therefore, the ability of P. cichorii SF1-54 to produce lipopeptides was investigated. A cell-free culture filtrate of SF1-54 showed surfactant, antimicrobial, and phytotoxic activities which are typical for lipopeptides. High-performance liquid chromatography analysis of P. cichorii SF1-54 culture filtrate revealed the presence of seven compounds with lipopeptide characteristics. Two related lipopeptides, named cichofactin A and B, were studied in more detail: they are linear lipopeptides with a decanoic and dodecanoic lipid chain, respectively, connected to the N-terminus of an eight-amino-acid peptide moiety. Both cichofactins are new members of the syringafactin lipopeptide family. Furthermore, two nonribosomal peptide synthethase-encoding genes, cifA and cifB, were identified as responsible for cichofactin biosynthesis. A cifAB deletion mutant no longer produced cichofactins and was impaired in swarming motility but showed enhanced biofilm formation. Upon spray inoculation on lettuce, the cichofactindeficient mutant caused significantly less rotten midribs than the wild type, indicating that cichofactins are involved in pathogenicity of P. cichorii SF1-54. Further analysis revealed that P. cichorii isolates vary greatly in swarming motility and cichofactin production. © 2013 The American Phytopathological Society. Source

Huang C.-J.,Ghent University | Huang C.-J.,National Chiayi University | Pauwelyn E.,Ghent University | Ongena M.,University of Liege | And 5 more authors.
Molecular Plant-Microbe Interactions

The lettuce midrib rot pathogen Pseudomonas cichorii SF1-54 produces seven bioactive compounds with biosurfactant properties. Two compounds exhibited necrosis-inducing activity on chicory leaves. The structure of the two phytotoxic compounds, named cichopeptin A and B, was tentatively characterized. They are related cyclic lipopeptides composed of an unsaturated C12-fatty acid chain linked to the Nterminus of a 22-amino acid peptide moiety. Cichopeptin B differs from cichopeptin A only in the last C-terminal amino acid residue, which is probably Val instead of Leu/Ile. Based on peptide sequence similarity, cichopeptins are new cyclic lipopeptides related to corpeptin, produced by the tomato pathogen Pseudomonas corrugata. Production of cichopeptin is stimulated by glycine betaine but not by choline, an upstream precursor of glycine betaine. Furthermore, a gene cluster encoding cichopeptin synthethases, cipABCDEF, is responsible for cichopeptin biosynthesis. A cipA-deletion mutant exhibited significantly less virulence and rotten midribs than the parental strain upon spray inoculation on lettuce. However, the parental and mutant strains multiplied in lettuce leaves at a similar rate. These results demonstrate that cichopeptins contribute to virulence of P. cichorii SF1-54 on lettuce. © 2015 The American Phytopathological Society. Source

Jacobs B.A.J.G.,42 Technology | Verlinden B.E.,42 Technology | Bobelyn E.,42 Technology | Decombel A.,Inagro VZW | And 6 more authors.
Postharvest Biology and Technology

Lamb's lettuce (Valerianella locusta L.) can be stored up to 28 days without being indistinguishable from fresh material by the human eye. However, due to the prior storage period the shelf life potential is limited and this leads to losses in distribution and a lower quality for the consumer. This work aims to develop a rapid and non-destructive methodology using visible/near infrared (Vis/NIR) reflectance spectroscopy to detect and quantify a prior storage period. Vis/NIR reflectance spectra were linked to the time in storage by partial least squares regression (PLS). Different variable selection techniques (interval PLS, Variable Importance in Projection scores, Genetic Algorithms PLS and Monte Carlo Uninformative Variable Elimination PLS) were combined to improve the accuracy and robustness of the prediction model, while decreasing the number of used wavelengths. The final model used only 10% of the original wavelengths, while the root mean squared error of cross validation decreased from 6.0 to 3.6 days. The final model was tested using 2 external test sets and had a maximum root mean square error of prediction of 3.7 days. Vis/NIR reflectance spectroscopy can be a valuable, rapid and non-destructive method for identifying and quantifying a prior storage period of lamb's lettuce. © 2015 Elsevier B.V. Source

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