17 research outputs found
Screening, isolation, and characterization of glycosyl-hydrolase-producing fungi from desert halophyte plants
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 activit
Synthesis, structure, and characterization of 4,4â˛-(Anthracene-9,10-diylbis(ethyne-2,1-diyl))bis(1-methyl-1-pyridinium) Bismuth Iodide (C30H22N2)3Bi4I18, an air, water, and thermally stable 0D hybrid Perovskite with high photoluminescence ffficiency
4,4'-(Anthracene-9,10-diylbis(ethyne-2,1-diyl))bis(1-methyl-1-pyridinium) bismuth iodide (C30H22N2)3Bi4I18 (AEPyBiI) was obtained as a black powder by a very simple route by mixing an acetone solution of BiI3 and an aqueous solution of C30H22N2I2. This novel perovskite is air and water stable and displays a remarkable thermal stability up to nearly 300 °C. The highly conjugated cation C30H22N2 2+ is hydrolytically stable, being nitrogen atoms quaternarized, and this accounts for the insensitivity of the perovskite toward water and atmospheric oxygen under ambient conditions. The cation in aqueous solution is highly fluorescent under UV irradiation (emitting yellow-orange light). AEPyBiI as well is intensely luminescent, its photoluminescence emission being more than 1 order of magnitude greater than that of high-quality InP epilayers. The crystal structure of AEPyBiI was determined using synchrotron radiation single-crystal X-ray diffraction. AEPyBiI was extensively characterized using a wide range of techniques, such as X-ray powder diffraction, diffuse reflectance UV-vis spectroscopy, Fourier transform infrared (FTIR) and Raman spectroscopies, thermogravimetry-differential thermal analysis (TG-DTA), elemental analysis, electrospray ionization mass spectroscopy (ESI-MS), and photoluminescence spectroscopy. AEPyBiI displays a zero-dimensional (0D) perovskite structure in which the inorganic part is constituted by binuclear units consisting of two face-sharing BiI6 octahedra (Bi2I9 3- units). The C30H22N2 2+ cations are stacked along the a-axis direction in a complex motif. Considering its noteworthy light-emitting properties coupled with an easy synthesis and environmental stability, and its composition that does not contain toxic lead or easily oxidable Sn(II), AEPyBiI is a promising candidate for environmentally friendly light-emitting devices
4,4â-(Thiophene-2,5-diylbis(ethyne-2,1-diyl))bis(1-methyl-1-pyridinium) Iodide
In the vast field of organic functional materials, viologens are widely recognized as an extremely versatile family of substances, due in part to the possibility of extending conjugation between the terminal pyridinium rings, for instance through the insertion of additional aromatic moieties. In this work, a new, extended viologen with a thiophene core and two acetylene bonds is presented. It was synthesized through a straightforward route, using well-established Sonogashira coupling reactions, and its optical properties were investigated by UVâvisible absorption and fluorescence spectroscopy, revealing a very interesting material for diverse fluorescence-related applications
Chitosan Production by Fungi: Current State of Knowledge, Future Opportunities and Constraints
Conventionally, the commercial supply of chitin and chitosan relies on shellfish wastes as the extraction sources. However, the fungal sources constitute a valuable option, especially for biomedical and pharmaceutical applications, due to the batch-to-batch unsteady properties of chitin and chitosan from conventional ones. Fungal production of these glycans is not affected by seasonality enables accurate process control and, consequently, more uniform properties of the obtained product. Moreover, liquid and solid production media often are derived from wastes, thus enabling the application of circular economy criteria and improving the process economics. The present review deals with fungal chitosan production processes focusing on waste-oriented and integrated production processes. In doing so, contrary to other reviews that used a genus-specific approach for organizing the available information, the present one bases the discussion on the bioprocess typology. Finally, the main process parameters affecting chitosan production and their interactions are critically discussed
Chitosan Production by Fungi: Current State of Knowledge, Future Opportunities and Constraints
Conventionally, the commercial supply of chitin and chitosan relies on shellfish wastes as the extraction sources. However, the fungal sources constitute a valuable option, especially for biomedical and pharmaceutical applications, due to the batchâtoâbatch unsteady properties of chitin and chitosan from conventional ones. Fungal production of these glycans is not affected by seasonality enables accurate process control and, consequently, more uniform properties of the obtained product. Moreover, liquid and solid production media often are derived from wastes, thus enabling the application of circular economy criteria and improving the process economics. The present review deals with fungal chitosan production processes focusing on wasteâoriented and integrated production processes. In doing so, contrary to other reviews that used a genusâspecific approach for organizing the available information, the present one bases the discussion on the bioprocess typology. Finally, the main process parameters affecting chitosan production and their interactions are critically discussed
Mechanisms of arsenic assimilation by plants and countermeasures to attenuate its accumulation in crops other than rice.
Arsenic is a ubiquitous metalloid in the biosphere, and its origin can be either geogenic or anthropic. Four oxidation states (â3, 0, +3 and + 5) characterize organic and inorganic As- compounds. Although arsenic is reportedly a toxicant, its harmful effects are closely related to its chemical form: inorganic compounds are most toxic, followed by organic ones and finally by arsine gas. Although drinking water is the primary source of arsenic exposure to humans, the metalloid enters the food chain through its uptake by crops, the extent of which is tightly dependent on its phytoavailability. Arsenate is taken up by roots via phosphate carriers, while arsenite is taken up by a subclass of aquaporins (NIP), some of which involved in silicon (Si) transport. NIP and Si transporters are also involved in the uptake of methylated forms of As. Once taken up, its distribution is regulated by the same type of transporters albeit with mobility efficiencies depending on As forms and its accumulation generally occurs in the following decreasing order: roots > stems > leaves > fruits (seeds). Besides providing a survey on the uptake and transport mechanisms in higher plants, this review reports on measures able to reducing plant uptake and the ensuing transfer into edible parts. On the one hand, these measures include a variety of plant-based approaches including breeding, genetic engineering of transport systems, graft/rootstock combinations, and mycorrhization. On the other hand, they include agronomic prac- tices with a particular focus on the use of inorganic and organic amendments, treatment of irrigation water, and fertilization
Il comportamento sismico della facoltĂ di ingegneria dellâaquila durante la sequenza sismica dellâaprile 2009
La sede della FacoltĂ di Ingegneria dellâUniversitĂ dellâAquila è ubicata a pochi chilometri a sud della cittĂ , in localitĂ Monteluco di Roio, sulla sommitĂ del colle omonimo, nel cuore del territorio interessato dalla sequenza sismica dellâAprile 2009. La FacoltĂ comprende diversi edifici, tutti realizzati con la tecnologia del calcestruzzo armato. Lâedificio di piĂš antica realizzazione, che rappresenta un importante esempio dellâarchitettura razionalista italiana, data ai primi decenni del â900 ed è destinato attualmente ad ospitare gli ambienti dipartimentali. Edifici di piĂš recente realizzazione, la cui costruzione è stata ultimata a metĂ degli anni â90, sono destinati prevalentemente ad uso didattico. Infine, alcuni edifici minori, destinati ad ospitare laboratori, sono realizzati in calcestruzzo armato precompresso. Nel suo complesso, la FacoltĂ rappresenta un campione significativo di costruzioni, che include esempi diversi per tipologie costruttive, etĂ di realizzazione, proprietĂ di regolaritĂ strutturale. La memoria illustra le conclusioni del lavoro condotto dallâUnitĂ Operativa di Ingegneria Sismica (UOIS) dellâUniversitĂ dellâAquila, orientato allâinterpretazione critica del comportamento sismico mostrato dai singoli edifici in occasione degli eventi piĂš catastrofici e, piĂš in generale, durante lâintera sequenza sismica che ha interessato il territorio aquilano. Scopo dellâindagine, che include anche le fasi di rilevamento e valutazione del danno tramite ispezione visiva, è lâinquadramento di tutte le componenti dellâorganismo edilizio, con particolare riguardo allâimpianto strutturale, analizzato anche con lâausilio di modelli numerici