38 results on '"Crognale, Silvia"'
Search Results
2. Cynara cardunculus a novel substrate for solid-state production of Aspergillus tubingensis cellulases and sugar hydrolysates
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Crognale, Silvia, Liuzzi, Federico, D'Annibale, Alessandro, de Bari, Isabella, and Petruccioli, Maurizio
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- 2019
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3. Main Factors Determining the Scale-Up Effectiveness of Mycoremediation for the Decontamination of Aliphatic Hydrocarbons in Soil.
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Antón-Herrero, Rafael, Chicca, Ilaria, García-Delgado, Carlos, Crognale, Silvia, Lelli, Davide, Gargarello, Romina Mariel, Herrero, Jofre, Fischer, Anko, Thannberger, Laurent, Eymar, Enrique, Petruccioli, Maurizio, and D'Annibale, Alessandro
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FUNGAL remediation ,ALIPHATIC hydrocarbons ,ENVIRONMENTAL remediation ,THERMAL desorption ,SOIL remediation - Abstract
Soil contamination constitutes a significant threat to the health of soil ecosystems in terms of complexity, toxicity, and recalcitrance. Among all contaminants, aliphatic petroleum hydrocarbons (APH) are of particular concern due to their abundance and persistence in the environment and the need of remediation technologies to ensure their removal in an environmentally, socially, and economically sustainable way. Soil remediation technologies presently available on the market to tackle soil contamination by petroleum hydrocarbons (PH) include landfilling, physical treatments (e.g., thermal desorption), chemical treatments (e.g., oxidation), and conventional bioremediation. The first two solutions are costly and energy-intensive approaches. Conversely, bioremediation of on-site excavated soil arranged in biopiles is a more sustainable procedure. Biopiles are engineered heaps able to stimulate microbial activity and enhance biodegradation, thus ensuring the removal of organic pollutants. This soil remediation technology is currently the most environmentally friendly solution available on the market, as it is less energy-intensive and has no detrimental impact on biological soil functions. However, its major limitation is its low removal efficiency, especially for long-chain hydrocarbons (LCH), compared to thermal desorption. Nevertheless, the use of fungi for remediation of environmental contaminants retains the benefits of bioremediation treatments, including low economic, social, and environmental costs, while attaining removal efficiencies similar to thermal desorption. Mycoremediation is a widely studied technology at lab scale, but there are few experiences at pilot scale. Several factors may reduce the overall efficiency of on-site mycoremediation biopiles (mycopiles), and the efficiency detected in the bench scale. These factors include the bioavailability of hydrocarbons, the selection of fungal species and bulking agents and their application rate, the interaction between the inoculated fungi and the indigenous microbiota, soil properties and nutrients, and other environmental factors (e.g., humidity, oxygen, and temperature). The identification of these factors at an early stage of biotreatability experiments would allow the application of this on-site technology to be refined and fine-tuned. This review brings together all mycoremediation work applied to aliphatic petroleum hydrocarbons (APH) and identifies the key factors in making mycoremediation effective. It also includes technological advances that reduce the effect of these factors, such as the structure of mycopiles, the application of surfactants, and the control of environmental factors. [ABSTRACT FROM AUTHOR]
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- 2023
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4. Experiences, considerations and potential of mycoremediation for decontamination of TPH in soil
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D'Annibale, Alessandro, Petruccioli, Maurizio, and Crognale, Silvia
- Abstract
LIFE MySOIL project presentation delivered by Alessandro d'Annibale, from the University of la Tuscia (UNITUS), during the workshop “Mycoremediation, a sustainable strategy for the recovery of oil-contaminated sites”, organised online by LIFE MySOIL on May 11th, 2023., This project has received funding from the LIFE Programme of the European Commission under contract number LIFE20 ENV/ES/000416.
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- 2023
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5. Evaluating the feasibility of the clean-up of hydrocarbon-contaminated soils by mycoaugmentation: the LIFE MySOIL project
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Bagnato, Fiora, Ciacciarelli, Rachele, Crognale, Silvia, D'Annibale, Alessandro, Lelli, Davide, Petruccioli, Maurizio, Villani, Federico, and Bonfedi, Guido
- Abstract
LIFE MySOIL project presentation delivered by Fiora Bagnato, from Eni Rewind, and Maurizio Petruccioli, from the University of La Tuscia (UNITUS) during the workshop SiCon 2023 Contaminated Sites – Experiences in Remediation Interventions, that was held from February 8th to 10th, 2023, in Rome (Italy)., This project has received funding from the LIFE Programme of the European Commission under contract number LIFE20 ENV/ES/000416.
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- 2023
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6. A step further in bioremediation: mycoremediation for soil recovery
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D'Annnibale, Alessandro, Crognale, Silvia, Lelli, Davide, and Petruccioli, Maurizio
- Abstract
LIFE MySOIL project presentation delivered by Maurizio Petruccioli, from the University of La Tuscia (UNITUS), during the Sustainability Day organised by UNITUS on October 5th, 2022., This project has received funding from the LIFE Programme of the European Commission under contract number LIFE20 ENV/ES/000416.
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- 2022
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7. Design and Analysis of a Novel Ultraviolet-C Device for Surgical Face Mask Disinfection
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Armentano, Ilaria, primary, Barbanera, Marco, additional, Belloni, Elisa, additional, Crognale, Silvia, additional, Lelli, Davide, additional, Marconi, Marco, additional, and Calabrò, Giuseppe, additional
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- 2022
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8. Cultivating conditions optimization of the anaerobic digestion of corn ethanol distillery residuals using response surface methodology
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Gyenge László, Ráduly Botond, Crognale Silvia, Lányi Szabolcs, and Ábrahám Beáta
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anaerobic digestion optimization ,response surface methodology ,corn ddgs ,process conditions ,inoculum type ,Chemistry ,QD1-999 - Published
- 2014
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9. Chitosan Production by Fungi: Current State of Knowledge, Future Opportunities and Constraints
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Crognale, Silvia, primary, Russo, Cristina, additional, Petruccioli, Maurizio, additional, and D’Annibale, Alessandro, additional
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- 2022
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10. Lignocellulolytic Potential of the Recently Described Species Aspergillus olivimuriae on Different Solid Wastes
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Carota, Eleonora, primary, Crognale, Silvia, additional, Russo, Cristina, additional, Petruccioli, Maurizio, additional, and D’Annibale, Alessandro, additional
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- 2021
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11. Fed-batch gluconic acid production from Penicillium variabile P16 under different feeding strategies
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Crognale, Silvia, Petruccioli, Maurizio, Fenice, Massimiliano, and Federici, Federico
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- 2008
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12. Enhanced production of β-glucan from Botryosphaeria rhodina using emulsified media or fan impellers
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Crognale, Silvia, Bruno, Maria, Moresi, Mauro, and Petruccioli, Maurizio
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- 2007
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13. Expression of Penicillium variabile P16 glucose oxidase gene in Pichia pastoris and characterization of the recombinant enzyme
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Crognale, Silvia, Pulci, Valentina, Brozzoli, Viviana, Petruccioli, Maurizio, and Federici, Federico
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- 2006
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14. Trematocine, a Novel Antimicrobial Peptide from the Antarctic Fish Trematomus bernacchii: Identification and Biological Activity
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Della Pelle, Giulia, primary, Perà, Giulia, additional, Belardinelli, Maria Cristina, additional, Gerdol, Marco, additional, Felli, Martina, additional, Crognale, Silvia, additional, Scapigliati, Giuseppe, additional, Ceccacci, Francesca, additional, Buonocore, Francesco, additional, and Porcelli, Fernando, additional
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- 2020
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15. Time-Dependent Changes in Morphostructural Properties and Relative Abundances of Contributors in Pleurotus ostreatus/Pseudomonas alcaliphila Mixed Biofilms
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Crognale, Silvia, primary, Stazi, Silvia Rita, additional, Firrincieli, Andrea, additional, Pesciaroli, Lorena, additional, Fedi, Stefano, additional, Petruccioli, Maurizio, additional, and D’Annibale, Alessandro, additional
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- 2019
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16. Aerobic Growth of Rhodococcus aetherivorans BCP1 Using Selected Naphthenic Acids as the Sole Carbon and Energy Sources
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Presentato, Alessandro, primary, Cappelletti, Martina, additional, Sansone, Anna, additional, Ferreri, Carla, additional, Piacenza, Elena, additional, Demeter, Marc A., additional, Crognale, Silvia, additional, Petruccioli, Maurizio, additional, Milazzo, Giorgio, additional, Fedi, Stefano, additional, Steinbüchel, Alexander, additional, Turner, Raymond J., additional, and Zannoni, Davide, additional
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- 2018
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17. Impact of the Fenton-like treatment on the microbial community of a diesel-contaminated soil
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Polli, Flavia, primary, Zingaretti, Daniela, additional, Crognale, Silvia, additional, Pesciaroli, Lorena, additional, D'Annibale, Alessandro, additional, Petruccioli, Maurizio, additional, and Baciocchi, Renato, additional
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- 2018
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18. Fungal Community Structure and As-Resistant Fungi in a Decommissioned Gold Mine Site
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Crognale, Silvia, primary, D'Annibale, Alessandro, additional, Pesciaroli, Lorena, additional, Stazi, Silvia R., additional, and Petruccioli, Maurizio, additional
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- 2017
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19. Rapid bioassay for evaluating enzyme production in fungal isolates from environmental sources
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Bordo, Eleonora, Luziatellie, Francesca, Crognale, Silvia, Marinari, Sara, Grego, Stefano, and Ruzzi, Maurizio
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- 2011
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20. Development and testing of a novel lab-scale direct steam-injection apparatus to hydrolyse model and saline crop slurries
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Guglielmo, Santi, Santi, Guglielmo, Alessandro, D'Annibale, D'Annibale, Alessandro, Maurizio, Petruccioli, Petruccioli, Maurizio, Silvia, Crognale, Crognale, Silvia, Maurizio, Ruzzi, Ruzzi, Maurizio, Riccardo, Valentini, Valentini, Riccardo, and Mauro, Moresi
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Crops, Agricultural ,Salinity ,Time Factors ,Steam injection ,Bioengineering ,Furfural ,Models, Biological ,Applied Microbiology and Biotechnology ,Autoclave ,chemistry.chemical_compound ,Hemicellulose ,Cellulose ,Steam explosion ,Xylose ,Sewage ,Tamaricaceae ,Chemistry ,business.industry ,Hydrolysis ,Superheated steam ,General Medicine ,Biotechnology ,Steam ,Glucose ,Slurry ,Laboratories ,business ,Nuclear chemistry - Abstract
In this work, a novel laboratory-scale direct steam-injection apparatus (DSIA) was developed to overcome the main drawback of the conventional batch-driven lab rigs, namely the long time needed to heat fiber slurry from room to reaction temperatures greater than 150 °C. The novel apparatus mainly consisted of three units: (i) a mechanically-stirred bioreactor where saturated steam at 5-30 bar can be injected; (ii) an automatic on-off valve to flash suddenly the reaction medium after a prefixed reaction time; (iii) a cyclone separator to recover the reacted slurry. This system was tested using 0.75 dm³ of an aqueous solution of H₂SO₄ (0.5%, v/v) enriched with 50 kg m⁻³ of either commercial particles of Avicel® and Larch xylan or 0.5 mm sieved particles of Tamarix jordanis. Each slurry was heated to about 200 °C by injecting steam at 28 bar for 90 s. The process efficiency was assessed by comparing the dissolution degree of suspended solid (Y(S)), as well as xylose (Y(X)), glucose (Y(G)), and furfural (Y(F)) yields, with those obtained in a conventional steam autoclave at 130 °C for 30 or 60 min. Treatment of T. jordanis particles in DSIA resulted in Y(S) and Y(G) values quite similar to those obtained in the steam autoclave at 130 °C for 60 min, but in a less efficient hemicellulose solubilization. A limited occurrence of pentose degradation products was observed in both equipments, suggesting that hydrolysis predominated over degradation reactions. The susceptibility of the residual solid fractions from DSIA treatment to a conventional 120 h long cellulolytic treatment using an enzyme loading of 5.4 FPU g⁻¹ was markedly higher than that of samples hydrolysed in the steam autoclave, their corresponding glucose yields being equal to 0.94 and 0.22 g per gram of initial cellulose, respectively. Thus, T. jordanis resulted to be a valuable source of sugars for bioethanol production as proved by preliminary tests in the novel lab rig developed here.
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- 2012
21. Time-Dependent Changes in Morphostructural Properties and Relative Abundances of Contributors in Pleurotus ostreatus / Pseudomonas alcaliphila Mixed Biofilms.
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Crognale, Silvia, Stazi, Silvia Rita, Firrincieli, Andrea, Pesciaroli, Lorena, Fedi, Stefano, Petruccioli, Maurizio, and D'Annibale, Alessandro
- Subjects
FATTY acid methyl esters ,PLEUROTUS ostreatus - Abstract
Pleurotus ostreatus dual biofilms with bacteria are known to be involved in rock phosphate solubilization, endophytic colonization, and even in nitrogen fixation. Despite these relevant implications, no information is currently available on the architecture of P. ostreatus -based dual biofilms. In addition to this, there is a limited amount of information regarding the estimation of the temporal changes in the relative abundances of the partners in such binary systems. To address these issues, a dual biofilm model system with this fungus was prepared by using Pseudomonas alcaliphila 34 as the bacterial partner due to its very fast biofilm-forming ability. The application of the bacterial inoculum to already settled fungal biofilm on a polystyrene surface coated with hydroxyapatite was the most efficient approach to the production of the mixed system the ultrastructure of which was investigated by a multi-microscopy approach. Transmission electron microscopy analysis showed that the adhesion of bacterial cells onto the mycelial cell wall appeared to be mediated by the presence of an abundant layer of extracellular matrix (ECM). Scanning electron microscopy analysis showed that ECM filaments of bacterial origin formed initially a reticular structure that assumed a tabular semblance after 72 h, thus overshadowing the underlying mycelial network. Across the thickness of the mixed biofilms, the presence of an extensive network of channels with large aggregates of viable bacteria located on the edges of their lumina was found by confocal laser scanning microscopy; on the outermost biofilm layer, a significant fraction of dead bacterial cells was evident. Albeit with tangible differences, similar results regarding the estimation of the temporal shifts in the relative abundances of the two partners were obtained by two independent methods, the former relying on qPCR targeting of 16S and 18S rRNA genes and the latter on ester-linked fatty acid methyl esters analysis. [ABSTRACT FROM AUTHOR]
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- 2019
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22. Draft Genome Sequence of Tepidimonas taiwanensis Strain VT154-175
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Valeriani, Federica, primary, Biagini, Tommaso, additional, Giampaoli, Saverio, additional, Crognale, Silvia, additional, Santoni, Daniele, additional, and Romano Spica, Vincenzo, additional
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- 2016
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23. Spoilage of oat bran by sporogenic microorganisms revived from soil buried 4000 years ago in Iranian archaeological site
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Milanesi, Claudio, primary, Cresti, Mauro, additional, Costantini, Lorenzo, additional, Gallo, Michele, additional, Gallo, Giuseppe, additional, Crognale, Silvia, additional, Faleri, Claudia, additional, Gradi, Alessandro, additional, and Franco, Baldi, additional
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- 2015
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24. Screening, isolation, and characterization of glycosyl-hydrolase-producing fungi from desert halophyte plants
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Luziatelli, Francesca, Crognale, Silvia, D’Annibale, Alessandro, Moresi, Mauro, Petruccioli, Maurizio, Ruzzi, Maurizio, Luziatelli, Francesca, Crognale, Silvia, D’Annibale, Alessandro, Moresi, Mauro, Petruccioli, Maurizio, and Ruzzi, Maurizio
- Abstract
Fungal strains naturally occurring on the wood and leaves of the salt-excreting desert tree Tamarix were isolated and characterized for their ability to produce cellulose- and starch- degrading enzymes. Of the 100 isolates, six fungal species were identified by ITS1 sequence analysis. No significant differences were observed among taxa isolated from wood samples of different Tamarix species, while highly salt-tolerant forms related to the genus Scopulariopsis (an anamorphic ascomycete) occurred only on the phylloplane of T. aphylla. All strains had cellulase and amylase activities, but the production of these enzymes was highest in strain D, a Schizophyllum-commune- related form. This strain, when grown on pretreated Tamarix biomass, produced an enzymatic complex containing levels of filter paperase (414 ± 16 IU/ml) that were higher than those of other S. commune strains. The enzyme complex was used to hydrolyze different lignocellulosic substrates, resulting in a saccharification rate of pretreated milk thistle (73.5 ± 1.2 %) that was only 10 % lower than that obtained with commercial cellulases. Our results support the use of Tamarix biomass as a useful source of cellulolytic and amylolytic fungi and as a good feedstock for the economical production of commercially relevant cellulases and amylases. [Int Microbiol 2014; 17(1):41-48]Keywords: Schizophyllum commune · Tamarix ssp. · cellulase activity · amylase activity
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- 2014
25. Airborne fungi in biofuel wood chip storage sites
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Barontini, Maurizio, primary, Crognale, Silvia, additional, Scarfone, Antonio, additional, Gallo, Pietro, additional, Gallucci, Francesco, additional, Petruccioli, Maurizio, additional, Pesciaroli, Lorena, additional, and Pari, Luigi, additional
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- 2014
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26. Corrigendum to “High production of cold-tolerant chitinases on shrimp wastes in bench-top bioreactor by the Antarctic fungus Lecanicillium muscarium CCFEE 5003: Bioprocess optimization and characterization of two main enzymes” [Enzyme Microb. Technol. 53 (5) (2013) 331–338]
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Barghini, Paolo, primary, Moscatelli, Deborah, additional, Garzillo, Anna Maria Vittoria, additional, Crognale, Silvia, additional, and Fenice, Massimiliano, additional
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- 2013
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27. High production of cold-tolerant chitinases on shrimp wastes in bench-top bioreactor by the Antarctic fungus Lecanicillium muscarium CCFEE 5003: Bioprocess optimization and characterization of two main enzymes
- Author
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Barghini, Paolo, primary, Moscatelli, Deborah, additional, Garzillo, Anna Maria Vittoria, additional, Crognale, Silvia, additional, and Fenice, Massimiliano, additional
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- 2013
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28. Corrigendum to “Development and testing of a novel lab-scale direct steam-injection apparatus to hydrolyse model and saline crop slurries” [J. Biotechnol. 157 (4) (2012) 590–597]
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Santi, Guglielmo, primary, D’Annibale, Alessandro, additional, Petruccioli, Maurizio, additional, Crognale, Silvia, additional, Ruzzi, Maurizio, additional, Valentini, Riccardo, additional, and Moresi, Mauro, additional
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- 2013
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29. Candida cylindracea: A model organism to study the possibility of using olive mill wastewaters as a substrate for lipase production
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Brozzoli, Viviana, primary, Crognale, Silvia, additional, Petruccioli, Maurizio, additional, Federici, Federico, additional, and D’Annibale, Alessandro, additional
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- 2007
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30. Enhanced separation of filamentous fungi by ultrasonic field: possible usage in repeated batch processes
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Crognale, Silvia, primary, Federici, Federico, additional, and Petruccioli, Maurizio, additional
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- 2002
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31. Cultivating conditions optimization of the anaerobic digestion of corn ethanol distillery residuals using response surface methodology.
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Gyenge, László, Ráduly, Botond, Crognale, Silvia, Lányi, Szabolcs, and Ábrahám, Beáta
- Abstract
This study investigated the individual and interactive effects of three factors - temperature, inoculum/substrate ratio (ISR) and inoculum typology - on the anaerobic digestion of corn ethanol distillery wastewater. Biochemical methane potential assays planned with factorial design with two independent quantitative variables on three levels (ISR: 1:1, 2:1 and 3:1; temperature: 30°C, 33.5°C, 37°C) and one independent qualitative variable (inoculum type: suspended, granular, mixed) have been performed. Response Surface Methodology has been used to study the effect of the factors with the aim of maximizing the specific methane yields (Y) obtainable with this substrate. The results show that all three investigated factors influence in a significant matter the Y, the ISR having the strongest effect on it. The temperature has significant influence on the Y only in combination with high ISR values. The optimal conditions for the maximum Y (551 mL CH g VS) have been found at 37°C operating temperature, ISR=3:1 and using granular inoculum. These conditions gave rise to a 4-fold increase of Y with respect to the worst combination of factors (Y=129 mL g VS for the suspended inoculum type, at 30°C and ISR=1:1). The results improve the knowledge on the digestion of this substrate, providing information for successful process up-scaling. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]
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- 2014
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32. Trematocine, a Novel Antimicrobial Peptide from the Antarctic Fish Trematomus bernacchii: Identification and Biological Activity
- Author
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Giuseppe Scapigliati, Giulia Della Pelle, Giulia Perà, Martina Felli, Francesco Buonocore, Francesca Ceccacci, Silvia Crognale, Marco Gerdol, Maria Cristina Belardinelli, Fernando Porcelli, Della Pelle, Giulia, Perà, Giulia, Belardinelli, Mariacristina, Gerdol, Marco, Felli, Martina, Crognale, Silvia, Scapigliati, Giuseppe, Ceccacci, Francesca, Buonocore, Francesco, and Porcelli, Fernando
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0301 basic medicine ,Microbiology (medical) ,antimicrobial peptide ,model membranes ,Antimicrobial peptides ,Peptide ,Biochemistry ,Microbiology ,Article ,03 medical and health sciences ,Minimum inhibitory concentration ,antimicrobial peptides ,Trematomus ,Pharmacology (medical) ,General Pharmacology, Toxicology and Pharmaceutics ,chemistry.chemical_classification ,Minimum bactericidal concentration ,030102 biochemistry & molecular biology ,biology ,lcsh:RM1-950 ,Biological activity ,Antimicrobial ,biology.organism_classification ,fish immune system ,Antarctica ,030104 developmental biology ,Infectious Diseases ,lcsh:Therapeutics. Pharmacology ,chemistry ,model membrane ,Bacteria - Abstract
Antimicrobial peptides (AMPs) are short peptides active against a wide range of pathogens and, therefore, they are considered a useful alternative to conventional antibiotics. We have identified a new AMP in a transcriptome derived from the Antarctic fish Trematomus bernacchii. This peptide, named Trematocine, has been investigated for its expression both at the basal level and after in vivo immunization with an endemic Antarctic bacterium (Psychrobacter sp. TAD1). Results agree with the expected behavior of a fish innate immune component, therefore we decided to synthesize the putative mature sequence of Trematocine to determine the structure, the interaction with biological membranes, and the biological activity. We showed that Trematocine folds into a &alpha, helical structure in the presence of both zwitterionic and anionic charged vesicles. We demonstrated that Trematocine has a highly specific interaction with anionic charged vesicles and that it can kill Gram-negative bacteria, possibly via a carpet like mechanism. Moreover, Trematocine showed minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against selected Gram-positive and Gram-negative bacteria similar to other AMPs isolated from Antarctic fishes. The peptide is a possible candidate for a new drug as it does not show any haemolytic or cytotoxic activity against mammalian cells at the concentration needed to kill the tested bacteria.
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- 2020
33. Aerobic growth of Rhodococcus aetherivorans BCP1 using selected naphthenic acids as the sole carbon and energy sources
- Author
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Alessandro Presentato, Martina Cappelletti, Anna Sansone, Carla Ferreri, Elena Piacenza, Marc A. Demeter, Silvia Crognale, Maurizio Petruccioli, Giorgio Milazzo, Stefano Fedi, Alexander Steinbüchel, Raymond J. Turner, Davide Zannoni, Presentato A., Cappelletti M., Sansone A., Ferreri C., Piacenza E., Demeter M.A., Crognale S., Petruccioli M., Milazzo G., Fedi S., Steinbuchel A., Turner R.J., Zannoni D., Presentato, Alessandro, Cappelletti, Martina, Sansone, Anna, Ferreri, Carla, Piacenza, Elena, Demeter, Marc A., Crognale, Silvia, Petruccioli, Maurizio, Milazzo, Giorgio, Fedi, Stefano, Steinbüchel, Alexander, Turner, Raymond J., and Zannoni, Davide
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0301 basic medicine ,Microbiology (medical) ,Inclusion bodie ,030106 microbiology ,lcsh:QR1-502 ,Settore BIO/19 - Microbiologia Generale ,7. Clean energy ,Microbiology ,lcsh:Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,Biosynthesis ,Rhodococcus aetherivorans, naphthenic acids, stress response, b-oxidation, transmission electron microscopy, fatty acids methyl esters, inclusion bodies ,naphthenic acids ,Beta oxidation ,chemistry.chemical_classification ,biology ,Stress response ,Rhodococcus aetherivoran ,Naphthenic acid ,Cyclohexanecarboxylic acid ,biology.organism_classification ,Rhodococcus aetherivorans ,chemistry ,Biochemistry ,Fatty acids methyl ester ,β-oxidation ,fatty acids methyl esters ,Energy source ,Rhodococcus ,Bacteria ,Intracellular ,Transmission electron microscopy ,Polyunsaturated fatty acid - Abstract
Naphthenic acids (NAs) are an important group of toxic organic compounds naturally occurring in hydrocarbon deposits. This work shows that Rhodococcus aetherivorans BCP1 cells not only utilize a mixture of eight different NAs (8XNAs) for growth but they are also capable of marked degradation of two model NAs, cyclohexanecarboxylic acid (CHCA) and cyclopentanecarboxylic acid (CPCA) when supplied at concentrations from 50 to 500 mgL−1 . The growth curves of BCP1 on 8XNAs, CHCA, and CPCA showed an initial lag phase not present in growth on glucose, which presumably was related to the toxic effects of NAs on the cell membrane permeability. BCP1 cell adaptation responses that allowed survival on NAs included changes in cell morphology, production of intracellular bodies and changes in fatty acid composition. Transmission electron microscopy (TEM) analysis of BCP1 cells grown on CHCA or CPCA showed a slight reduction in the cell size, the production of EPS-like material and intracellular electrontransparent and electron-dense inclusion bodies. The electron-transparent inclusions increased in the amount and size in NA-grown BCP1 cells under nitrogen limiting conditions and contained storage lipids as suggested by cell staining with the lipophilic Nile Blue A dye. Lipidomic analyses revealed significant changes with increases of methyl-branched (MBFA) and polyunsaturated fatty acids (PUFA) examining the fatty acid composition of NAs-growing BCP1 cells. PUFA biosynthesis is not usual in bacteria and, together with MBFA, can influence structural and functional processes with resulting effects on cell vitality. Finally, through the use of RT (Reverse Transcription)- qPCR, a gene cluster (chcpca) was found to be transcriptionally induced during the growth on CHCA and CPCA. Based on the expression and bioinformatics results, the predicted products of the chcpca gene cluster are proposed to be involved in aerobic NA degradation in R. aetherivorans BCP1. This study provides first insights into the genetic and metabolic mechanisms allowing a Rhodococcus strain to aerobically degrade NAs. 
- Published
- 2018
34. Produzione di bioetanolo di seconda generazione da pastazzo di arance
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Santi, Guglielmo and Crognale, Silvia
- Subjects
Pastazzo di arance ,Idrolisi enzimatica ,Enzymatic hydrolysis ,Fermentation ,Bioetanolo ,BIO/19 ,Bioethanol ,Fermentazione ,Steam explosion ,Orange peel waste - Abstract
The present PhD thesis was aimed at assessing the feasibility of second generation bioethanol production from a few food-processing lignocellulosic residues. To this purpose, three residues (orange peel waste, olive pomace and grape pomace) were chemically characterized and orange peel waste (OPW) appeared to be the most promising matrix, the total fermentable sugars amounting up to about 48% of the dry matter. A novel lab-scale direct steam injection apparatus was used to perform an acid-catalyzed steam-explosion (ACSE) pretreatment of the selected matrix under four temperature-time conditions. The performance of the ACSE pretreatments was also compared with that of a conventional autoclave. ACSE pretreatments at 200 °C for 90 s and 180 °C for 150 s led to the highest pectin solubilization (about 73%) with a positive effect on the subsequent enzymatic hydrolysis step, performed with a commercial cellulase. The highest depolymerization yield (about 57%) was obtained from the solid pretreated at 180 °C for 150 s. The resulting hydrolyzate was efficiently fermented by the industrial strain S. cerevisiae F15 in the shaken-flask scale under repeated-batch conditions. To scale-up the previous results, a new ACSE trial at 180 °C for 90 s was performed by tripling the solid loading, and the entire process feasibility was assessed at the bench-reactor scale. On the basis of a mass balance including all the glucose and fructose (11.13% dm) released after pretreatment at 180 °C for 150 s at triple solid loading and the glucose freed after enzymatic hydrolysis (17.86% dm), and accounting for an overall ethanol yield of 41.5%, the overall process yield at the bench-reactor scale would amount to about 153 L bioethanol per metric ton dry OPW. Questa tesi di dottorato ha l’obiettivo di verificare la fattibilità della produzione di bioetanolo di seconda generazione da scarti lignocellulosici di processamento degli alimenti. A tale scopo sono stati caratterizzati tre residui (pastazzo di arance, sansa di olive e vinacce) e il pastazzo è risultato essere la matrice più promettente, con un quantitativo di zuccheri fermentabili pari a circa il 48% del peso secco. Un pretrattamento di steam explosion del pastazzo è stato effettuato a diversi tempi e temperature utilizzando un prototipo ad iniezione di vapore su scala di laboratorio. La performance dei pretrattamenti di steam explosion è stata paragonata a quella di un’autoclave convenzionale. I pretrattamenti di steam explosion a 200 °C per 90 s e 180 °C per 150 s hanno portato alla massima solubilizzazione della pectina (circa il 73%) con un effetto positivo sulla successiva idrolisi enzimatica. La massima resa di depolimerizzazione (circa il 57%) è stata ottenuta con il solido pretrattato a 180 °C per 150 s. L’idrolizzato è stato fermentato efficientemente dal ceppo industriale S. cerevisiae F15 in beuta agitata in condizioni di batch ripetuto. Al fine di effettuare uno scale-up dei precedenti esperimenti, è stata effettuata una nuova prova a 180 °C per 150 s a triplo carico di solido, e la fattibilità dell’intero processo è stata valutata in reattore da banco. Sulla base di un bilancio di massa che include il glucosio e il fruttosio (11.13% del peso secco) rilasciati dopo pretrattamento a 180 °C per 150 s a triplo carico di solido, e il glucosio liberato dopo idrolisi enzimatica (17.85% del peso secco), e considerando una resa in etanolo del 41.5%, la resa complessiva del processo ammonterebbe a 153 L di etanolo per tonnellata di pastazzo secco. Dottorato di ricerca in Biotecnologia degli alimenti
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- 2012
35. Ri-utilizzo dei reflui dei frantoi oleari per la produzione biotecnologica di lipasi microbiche
- Author
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Brozzoli, Viviana and Crognale, Silvia
- Subjects
Ottimizzazione processo fermentativo ,Valorizzazione reflui oleari ,BIO/19 ,Lipasi - Abstract
Lo smaltimento delle acque di vegetazione dei frantoi oleari costituisce, attualmente, uno dei principali problemi dal punto di vista ambientale, specialmente nei paesi del Mediterraneo dove si concentra la maggior parte della produzione mondiale di olio di oliva. Le acque di vegetazione sono tra i reflui agro-industriali a più alto tasso inquinante a causa del loro elevato carico organico, caratterizzato soprattutto da composti fenolici e polifenolici ad elevata azione antimicrobica e fitotossica. La purificazione biologica delle acque di vegetazione è particolarmente difficile poiché questo refluo presenta solidi in sospensione e un elevato carico organico, in particolare polifenoli con attività biostatica e/o biocida, che riduce fortemente le prestazione degli impianti di depurazione. Di conseguenza, l’impianto deve prevedere due o più stadi di trattamento che rendono la depurazione complessa e costosa. Attualmente, la normativa vigente consente la pratica dello spandimento delle acque di vegetazione sui terreni agrari; nonostante questa risulti, al momento, essere la soluzione migliore sia dal punto di vista pratico che economico, trova attuazione solo se si ha disponibilità di terreni sufficientemente vicini su cui spargere il refluo e comunque deve essere applicata in maniera controllata dal momento che gli eventuali effetti positivi o negativi sulla composizione, sulla carica microbica e la fertilità del terreno sono ancora oggi oggetto di studio. Inoltre, la migrazione di alcuni composti negli strati più bassi del terreno potrebbe causare la contaminazione di eventuali falde acquifere sottostanti con conseguenze per la salute dell’uomo. Negli ultimi anni sono state proposte soluzioni alternative finalizzate a sfruttare questo refluo, in quanto ricco di composti utili. La valorizzazione delle AV mediante il loro impiego per l’ottenimento di prodotti a medio o alto valore aggiunto attraverso processi fisico-chimici o fermentativi, riveste notevole interesse scientifico. Nelle AV sono presenti una grande varietà di biomolecole come acidi organici, polialcoli, zuccheri semplici e complessi e lipidi che le rendono una possibile base per i processi fermentativi. In virtù del contenuto residuo di lipidi, le AV potrebbero rappresentare un ottimo candidato come terreno liquido di crescita per la produzione di lipasi microbiche. Lo scopo della presente tesi di dottorato è stato quello di mettere a punto un processo fermentativo per la valorizzazione delle AV mediante produzione microbica di enzimi, in particolare enzimi lipolitici, ottenendo al contempo un abbattimento, o quanto meno una riduzione, del loro potere inquinante. Esiste una vasta bibliografia in cui viene presa in esame la produzione di lipasi da numerose specie microbiche tra cui Penicillium e Candida e sia il terreno che il processo fermentativo per la produzione di questo enzima è stato ampiamente ottimizzato. Nella maggior parte dei casi, una buona produzione di lipasi microbica prevede l’utilizzo di terreni sintetici piuttosto complessi che sicuramente incidono in maniera significativa sul prezzo finale del prodotto. Inoltre, negli ultimi anni anche la produzione di preparati enzimatici commerciali contenenti lipasi di origine microbica ha avuto un notevole sviluppo. Sigma, Amano, Roche, Novo Nordisk, etc., forniscono preparati lipolititici con varie composizioni e proprietà catalitiche utilizzati in diversi settori: industria alimentare, farmaceutica, dei detergenti e per la produzione di biodiesel. L’innovazione che dovrebbe introdurre questo lavoro è l’opportunità di produrre lipasi microbiche di possibile interesse industriale utilizzando un substrato costituito da un refluo agro-industriale. Con questa idea, si è cercato di mettere a punto un terreno di produzione a basso costo che permettesse di ottenere buoni livelli di attività e contemporaneamente un abbattimento del carico inquinante del refluo finale. In prima battuta, è stato effettuato uno screening di microrganismi (Geotrichum candidum, NRRL 552, 553; Rhizopus sp, ISRIM 383; Rhizopus arrhizus, NRRL 2286; Rhizopus oryzae, NRRL 6431; Aspergillus oryzae, NRRL 1988, 495; Aspergillus niger, NRRL 334; Candida cylindracea, NRRL Y-17506; Penicillium citrinum, NRRL 1841, 3754, ISRIM 118) in grado di crescere sulle acque di vegetazione producendo lipasi. Le produzioni più elevate di enzima sono state ottenute, in condizioni non-ottimizzate, dopo 168 h con Geotrichum candidum NRRL 553 (0,521 U/ml) e Candida cylindracea (0,460 U/ml). Inoltre, livelli di produzione molto interessanti sono stati raggiunti dopo 72 h con i ceppi di Penicillium citrinum (0,365, 0,320 e 0,375 U/ml per NRRL 1841, NRRL 3754 e ISRIM 118, rispettivamente). Questi ceppi sono stati selezionati per valutare, in via preliminare, l’effetto di alcuni fattori sulla produzione di lipasi quali tipologia di AV, utilizzo di vari oli come induttori di attività e impiego di diverse fonti di azoto. Per quanto riguarda la produzione di lipasi da P. citrinum NRRL 1841 su AV, l’attività è stata influenzata in maniera marcata dal tipo di fonte di azoto ma non era aumentata in maniera significativa dall’aggiunta di oli. Nel caso della produzione di lipasi da C. Cylindracea NRRL Y-17506, il cloruro di ammonio e l’olio di oliva rappresentavano rispettivamente la fonte di azoto e l’induttore più adatto; infatti questo ceppo cresciuto in condizioni parzialmente ottimizzate produceva 9,48 U/ml di attività lipolitica dopo 264 h di fermentazione. Successivamente, la produzione di lipasi da P. citrinum NRRL 1841, utilizzando il terreno a base di AV, è stata ottimizzata in beuta valutando l’effetto del pH iniziale, della concentrazione di azoto e di estratto di lievito secondo un approccio multi-fattoriale. La combinazione ottimizzata dal modello è stata la seguente: pH 6,15, 2,7 g/l NH4Cl e 1,1 g/l YE. La produzione massima raggiunta è stata di 1,242 U/ml. Con il terreno così ottimizzato, al fine di ottenere informazioni sul possibile trasferimento di scala del processo, sono stati condotti altri esperimenti in reattori da banco. Allo scopo, sono stati impiegati due tipi di sistemi, un bioreattore ad agitazione meccanica (STR) e uno ad agitazione pneumatica (Air-lift). In entrambi i casi, l’attività lipolitica extracellulare aveva raggiunto il suo picco massimo dopo 192 h di fermentazione. Tuttavia, il massimo di attività è stato significativamente più alto in STR che in Airlift (0,700 vs 0,420 U/ml, rispettivamente). Sebbene tutti i ceppi studiati sono stati in grado di crescere sulle acque di vegetazione e produrre a livelli significativi attività lipolitica, una particolare attenzione è stata riservata a C. cylindracea (noto anche come C. rugosa) per il notevole interesse applicativo della lipasi prodotta da questo lievito. Inizialmente, si è cercato di ottimizzare in beuta la composizione del terreno di produzione (concentrazione dell’olio di oliva, effetto del glucosio, aggiunta di surfactanti e di vari fattori di crescita) e di valutare in via preliminare l’effetto sulla crescita cellulare e sull’attività di alcune condizioni colturali quali velocità di agitazione e aerazione. La migliore composizione del terreno di produzione si è confermata essere quella contenente 3 g/l di olio di oliva, 2,4 g/l di NH4Cl e 0,5 g/l di estratto di lievito, senza l’aggiunta di glucosio e Tween 80. Inoltre, con lo scopo di valutare la fattibilità tecnica di un trasferimento di scala del bioprocesso e approfondire la messa a punto del processo fermentativo sono stati condotti una serie di esperimenti in bioreattore da banco ad agitazione meccanica (STR). In particolare, utilizzando il terreno a base di AV ottimizzato, si è cercato di ottimizzare alcuni parametri quali pH, velocità di agitazione e aerazione. Per quanto riguarda l’effetto della velocità di agitazione e dell’aerazione sulla produzione enzimatica, sono state prese in esame tre velocità di agitazione (300, 500 e 700 giri/min), mantenute fisse durante tutta la fermentazione, e in più è stato condotto un esperimento in cui si è cercato di mantenere la concentrazione dell’ossigeno disciolto nel mezzo superiore al 20% di saturazione facendo variare la velocità di agitazione tra 300 e 800 giri/min. Mentre per valutare l’effetto del pH, sono stati condotti degli esperimenti a pH 6,5 fisso confrontando la produzione con quella ottenuta a pH libero e a pH mantenuto inferiore a 6,5. La massima produzione di lipasi da C. cylindracea è stata ottenuta in bioreattore lavorando a pH libero e ad una velocità di agitazione costante di 500 giri/min (18,50 U/ml) o ad una velocità di agitazione variabile tra 300 e 800 giri/min in modo da assicurare un valore di ossigeno disciolto nel brodo superiore al 20% di saturazione (18,70 U/ml); in quest’ultimo caso, inoltre, la comparsa del picco massimo è stata anticipata nel tempo favorendo così la produttività oraria del bioprocesso. Per quanto riguarda i reattori a 300 e 700 giri/min, la produzione enzimatica è stata di 2,54 e 11,65 U/ml, rispettivamente. Infine, messo a punto il bioprocesso di produzione della lipasi da C. cylindracea coltivata su un terreno a base di AV, si è cercato di identificare il profilo enzimatico del campione grezzo così ottenuto, dal momento che, come è noto dalla letteratura, questo lievito è in grado di produrre fino a sette isoforme ad attività lipolitica. A tale scopo sono stati condotti degli esperimenti di isoelettrofocalizzazione (IEF) analitica. Nel gel sono stati caricati un campione di lipasi commerciale (Tipo VII, Sigma) e due campioni grezzi ottenuti da C. cylindracea coltivata sul terreno a base di AV, prelevati a due tempi fermentativi diversi e corrispondenti ai due picchi di attività lipolitica raggiunti durante le prove in STR (I° e II° picco di massima attività, 48esima e 192esima ora, rispettivamente). Dai risultati ottenuti, è stato osservato che il campione grezzo era costituito da più isoenzimi con attività lipolitica e che il profilo isoenzimatico aveva una sola banda in comune con quello della lipasi commerciale (Typo VII, Sigma) a cui è stato assegnato pI 4,7. Per quanto riguarda il campione prelevato alla 48esima ora, sono state osservate anche una banda piuttosto intensa a pI 5,1 e una tripletta di bande più deboli a pIs di 5,06, 5,0 e 4,9. Durante la fermentazione il profilo isoenzimatico del campione aveva subito delle modifiche: infatti, alla 192esima ora, le bande a pIs 5,1, 5,0 e 4,9 erano scomparse, mentre era comparsa una banda di attività intensa a cui è stato assegnato un pI di 4,5. Infine, in entrambi i campioni grezzi è stata rilevata una banda tenue a pI 3,8. In conclusione, i buoni livelli di attività enzimatica raggiunti dimostrano la fattibilità tecnica di un processo fermentativo finalizzato alla valorizzazione dei reflui oleari mediante la produzione di lipasi, che può avere promettenti utilizzi in varie applicazioni industriali. Comunque, ulteriori fasi di scale-up del processo sono ancora necessarie al fine di poter effettuare una valutazione sulla fattibilità economica del processo. The olive mill wastewater (OMW) disposal is, currently, one of the main environmental problems in all olive-oil producing countries, especially in the Mediterranean area. In fact, for its high organic load, phenolic fraction with phytotoxic effects and antimicrobial activity, the OMW is a highly polluted agro-industrial effluent. The biological treatment can be very difficult since solid residues, high organic load and phenols may strongly reduce the depuration efficiency. Consequently, a possible process should include several technological options, physical, chemical and biological, as well as combinations thereof, thus resulting in increased process costs. At the moment, the Italian legislation allows land spreading of untreated olive mill wastewater that is the best economical solution. Application on agriculture soils is a practice which solves partially the problem of OMW disposal. Positive and negative effects on soil composition and fertility are still under study, so that OMW application must be strictly controlled. Land spreading, in fact, may cause serious negative environmental impact regarding, for instance, groundwater contamination. In the last years, alternative solutions have been proposed in view of the use this waste as a source of valuable compounds. Several recent research studies have reported the possibility of OMW valorization to obtain products of actual or potential industrial interest. The presence in OMW of a wide range of biomolecules such as organic acids, polyalcohols, simple and complex sugars and lipids makes it a potential basis for fermentation processes. In this way, OMW could be a putative candidate as a potentially suitable liquid growth medium for the production of microbial lipases by virtue of its residual lipid content. For these reasons, the objective of the present PhD thesis was to assess the suitability of OMW as growth medium for the production of lipases and to set up a related fermentation process that might lead, at the same time, to a low polluting load final effluent. A large number of microbial strains have been screened for lipase production belonging to several fungal genera, Candida and Penicillium in particular. In literature, numerous methods for lipolytic enzyme production are published and medium composition and cultural conditions have been fully optimised. Neverthless, the most frequently used medium is a chemical defined and complex one, significantly affecting the final product costs. Besides, in the last years, a whole range of microbial lipase preparations has been developed. Sigma, Amano, Roche, Novo Nordisk, etc., provide lipolytic preparations with various compositions and catalytic proprierties employed in areas such as detergent pharmaucetic and food industries and biodiesel production. Our innovative approach consists in the trial of producing microbial lipases using an agroindustrial-waste based medium. Our basic idea, in fact, was that of developing a low cost production medium. Firstly, 12 fungal strains belonging to well-known lypolytic species (Geotrichum candidum, NRRL 552, 553; Rhizopus sp, ISRIM 383; Rhizopus arrhizus, NRRL 2286; Rhizopus oryzae, NRRL 6431; Aspergillus oryzae, NRRL 1988, 495; Aspergillus niger, NRRL 334; Candida cylindracea, NRRL Y-17506; Penicillium citrinum, NRRL 1841, 3754, ISRIM 118) were screened for their ability to grow on undiluited OMW and to produce extracellular lipase activity. The highest lipase productions were obtained under non-optimized conditions after 168 h with Geotrichum candidum NRRL 553 (0.521 U/ml) and Candida cylindracea (0.460 U/ml). Interesting production levels were also achieved after 72 h with strains of Penicillium citrinum (0.365, 0.320 and 0.375 U/ml for NRRL 1841, NRRL 3754 and ISRIM 118, respectively). These strains were then selected to study the effect of culture conditions, such as OMW typology, nitrogen sources and inducers, on the enzyme production. With regard to the lipase production by P. citrinum NRRL 1841, the enzyme activity was significantly influenced by nitrogen addition; on the other hand, the addition of oils resulted in a marked increase in biomass without affecting, however, lipase production. Lipase production by C. cylindracea NRRL Y-17506 was significatly favored by ammonium salts and oil addition. This strain growth in OMW medium containing ammonium chloride and olive oil led to an activity peak of 9.48 U/ml after 264 hours of fermentation. In order to optimise lipase production by P. citrinum in OMW-based medium, the combined effect of three variables (i.e, concentration of NH4Cl, yeast extract and initial pH) was assessed using a multi-factorial design with ‘optimizer’ function of ‘Modde 5.0’ program. The optimised combination by the model was as follows: pH 6.15, 2.7 g/l NH4Cl e 1.1 g/l extract yeast. The maximum lipase activity was 1.242 U/ml after 192 hour of fermentation. To gain information on the possible up-scaling of the process, further experiments were performed in 3-l laboratory-scale reactors. Specifically, pneumatically agitated (Airlift) and mechanically agitated (STR) reactors were employed using the optimised OMW-based medium. In both cases, the extracellular lipase peaked 192 h after inoculation. Howewer, the maximum activity was significatly higher in STR with respect to the Airlift (0.700 vs 0.420 U/ml, respectively). Of all strains, C. cylindracea appeared to be particularly interesting and was, therefore, used as the model microorganism to further investigate the feasibility of an OMW substrate. Firstly, the optimisation of medium composition was assessed in shaken cultures. In particular, the effects on the lipase production of olive oil concentration (1, 3, 5 e 10 g/l), glucose (5 g/l), Tween 80 (0,5 g/l) and several growth nutrients (yeast extract, malt extract and peptone) addition were studied. The best medium composition was as follows: diluited OMW (1:2), olive oil 3 g/l, NH4Cl 2.4 g/l and yeast extract 0.5 g/l. The glucose and Tween 80 addition negatively affected the production of lipolytic enzyme. Lipase production by C. cylindracea on OMW-optimized medium was subsequently assessed in mechanically agitated bioreactor (STR). To study the agitation influence on enzyme production, a set of experiments was carried out at three impeller speed, 300, 500 and 700 rpm; moreover, an additional experiment was carried out at dissolved oxygen DO > 20% saturation (agitation speed automatically controlled between 300 and 800 rpm). To evaluate the effect of pH, three conditions were compared: free pH; fixed pH (6.5) maintained constant by addition of HCl 4.0 M and NaOH 4.0 M; pH lower than 6.5 controlled with addition of HCl 4.0 M. The maximum lipase productions were obtained with the pH left free to vary, 500 rpm costant agitation speed (18.5 U/ml) and variable agitation speed between 300 and 800 rpm to ensure a dissolved oxygen value upper to 20% (18.7 U/ml); in the latter thesis the onset of enzyme activity was anticipated thus leading to increased bioprocess productivity. At 300 e 700 rpm agitation speed, the maximum lipase productions were 2.54 and 11.65 U/ml, respectively. Finally, to set up the bioprocess of lipase production by C. Cylindracea grown on OMW-based medium, the isoenzymatic profiles of the raw sample was evaluated. This aspect appears to be very interesting since it is known that commercial C. rugosa lipase is a mixture of 3 isoenzymes namenly Lip 1, Lip2 and Lip 3 but the yeast is able to produce up to seven different isoenzymes (Lip 1-Lip 7). Moreover isoenzymatic profiles can depend on media composition and fermentation conditions. With this aim, a set of analitycal isoelectrofocusing experiments were carried out. In the gels, a sample of commercial lipase (Type VII, Sigma) and two raw samples of lipase by C. cylindracea grown on OMW-optimized medium and corresponding to two lipolytic activity peaks (1st and 2nd peak, 48esime and 192esime hour of fermentation, respectively) obtained in STR, were loaded. The results suggest that the raw samples were constituted of more lipolytic isoenzymes with the isoenzymatic profile having only one band in common with that of the commercial lipase (assigned pI 4.7). The sample corresponding to the 1st activity peak showed a strong band at pI 5.1 and a triplette of weak bands at pIs 5.06, 5.0 e 4.9. Moreover, the isoenzymatic profiles changed during fermentation; in fact, the bands at pIs 5.1, 5.0 and 4.9 disappeared and a new strong band at pI 4.5 formed. Finally, in both raw samples a band at pI 3.8 was observed. OMWs valorisation by its use as growth medium for lipase production by C. cylindracea NRRL Y-17506 and P. citrinum NRRL 1841 appears to be possible and promising. Moreover, the investigation for further up-scaling is need to evaluate the economic fattibility of the bioprocess. Dottorato di ricerca in Biotecnologie degli alimenti
- Published
- 2008
36. Metagenomic analysis of bacterial community in a travertine depositing hot spring.
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Valeriani F, Crognale S, Protano C, Gianfranceschi G, Orsini M, Vitali M, and Spica VR
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- Bacteria isolation & purification, Biodiversity, Computational Biology, DNA, Bacterial genetics, Phylogeny, RNA, Bacterial genetics, RNA, Ribosomal, 16S genetics, Bacteria genetics, Hot Springs microbiology, Metagenomics methods, Water Microbiology
- Abstract
Several factors influence bacteria biodiversity in hot springs. The impact of biotic and abiotic pathways on travertine deposition plays a key role in microbial ecology and in the final composition of the waterborne microbiota. The metabolism of some bacterial groups such as photoautotrophs or lithoautotrophs influences water chemistry, favoring carbonate precipitation processes. The role of microbial mats in mineral precipitation processes is not fully clarified. For the first time, a comprehensive metagenomic analysis has been undertaken in the historical Bullicame hot spring. Bacterial biodiversity was characterized and biomineralization activities were assigned to different genera. A higher biodiversity in mat samples compared to water samples was observed: Shannon index of 3.34 and 0.86, respectively. Based on the functional assignment of each Operational Taxonomic Unit, the bacteria involved in biologically- induced mineralization are prevalent in mat and released in the water. According to the principle that each geothermal water specimen has distinctive physic-chemical characteristics, our results suggest new interacting bio-actions within these ecosystems. The saturation index and the chemical composition, as the high concentration of sulfur species and HCO3, can be linked to create a selective environment where pioneer communities are able to live and shape the ecosystem.
- Published
- 2018
37. Screening, isolation, and characterization of glycosyl-hydrolase-producing fungi from desert halophyte plants.
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Luziatelli F, Crognale S, D'Annibale A, Moresi M, Petruccioli M, and Ruzzi M
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- Desert Climate, Fungal Proteins chemistry, Fungal Proteins genetics, Fungi chemistry, Fungi classification, Hydrolases chemistry, Hydrolases genetics, Molecular Sequence Data, Phylogeny, Fungal Proteins metabolism, Fungi enzymology, Fungi isolation & purification, Hydrolases metabolism, Salt-Tolerant Plants microbiology, Tamaricaceae microbiology
- Abstract
Fungal strains naturally occurring on the wood and leaves of the salt-excreting desert tree Tamarix were isolated and characterized for their ability to produce cellulose- and starch-degrading enzymes. Of the 100 isolates, six fungal species were identified by ITS1 sequence analysis. No significant differences were observed among taxa isolated from wood samples of different Tamarix species, while highly salt-tolerant forms related to the genus Scopulariopsis (an anamorphic ascomycete) occurred only on the phylloplane of T. aphylla. All strains had cellulase and amylase activities, but the production of these enzymes was highest in strain D, a Schizophyllum-commune-related form. This strain, when grown on pretreated Tamarix biomass, produced an enzymatic complex containing levels of filter paperase (414 +/- 16 IU/ml) that were higher than those of other S. commune strains. The enzyme complex was used to hydrolyze different lignocellulosic substrates, resulting in a saccharification rate ofpretreated milk thistle (73.5 +/- 1.2%) that was only 10% lower than that obtained with commercial cellulases. Our results support the use of Tamarix biomass as a useful source of cellulolytic and amylolytic fungi and as a good feedstock for the economical production of commercially relevant cellulases and amylases.
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- 2014
- Full Text
- View/download PDF
38. Development and testing of a novel lab-scale direct steam-injection apparatus to hydrolyse model and saline crop slurries.
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Santi G, D'Annibale A, Petruccioli M, Crognale S, Ruzzi M, Valentini R, and Moresi M
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- Cellulose analysis, Crops, Agricultural chemistry, Glucose analysis, Hydrolysis, Models, Biological, Time Factors, Xylose analysis, Biotechnology instrumentation, Biotechnology methods, Laboratories, Salinity, Sewage chemistry, Steam, Tamaricaceae chemistry
- Abstract
In this work, a novel laboratory-scale direct steam-injection apparatus (DSIA) was developed to overcome the main drawback of the conventional batch-driven lab rigs, namely the long time needed to heat fiber slurry from room to reaction temperatures greater than 150 °C. The novel apparatus mainly consisted of three units: (i) a mechanically-stirred bioreactor where saturated steam at 5-30 bar can be injected; (ii) an automatic on-off valve to flash suddenly the reaction medium after a prefixed reaction time; (iii) a cyclone separator to recover the reacted slurry. This system was tested using 0.75 dm³ of an aqueous solution of H₂SO₄ (0.5%, v/v) enriched with 50 kg m⁻³ of either commercial particles of Avicel® and Larch xylan or 0.5 mm sieved particles of Tamarix jordanis. Each slurry was heated to about 200 °C by injecting steam at 28 bar for 90 s. The process efficiency was assessed by comparing the dissolution degree of suspended solid (Y(S)), as well as xylose (Y(X)), glucose (Y(G)), and furfural (Y(F)) yields, with those obtained in a conventional steam autoclave at 130 °C for 30 or 60 min. Treatment of T. jordanis particles in DSIA resulted in Y(S) and Y(G) values quite similar to those obtained in the steam autoclave at 130 °C for 60 min, but in a less efficient hemicellulose solubilization. A limited occurrence of pentose degradation products was observed in both equipments, suggesting that hydrolysis predominated over degradation reactions. The susceptibility of the residual solid fractions from DSIA treatment to a conventional 120 h long cellulolytic treatment using an enzyme loading of 5.4 FPU g⁻¹ was markedly higher than that of samples hydrolysed in the steam autoclave, their corresponding glucose yields being equal to 0.94 and 0.22 g per gram of initial cellulose, respectively. Thus, T. jordanis resulted to be a valuable source of sugars for bioethanol production as proved by preliminary tests in the novel lab rig developed here., (Copyright © 2011 Elsevier B.V. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
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