Authors:D. Hadanich, J. Perédi, M. Juhász-Román and B. Nagy
In the microflora of sunflower seeds stored in domestic stores the,
species dominate, while those of
Penicillium, Trichoderma, Stemphylium
spp. are present in lower numbers. During model tests (cca 20% seed moisture content, 25 °C, 4 weeks storage) the
species were almost completely eliminated and on the seeds mainly
species, characteristic of stores, propagated. The moulds significantly deteriorated the quality of the seed and that of the produced oil and meal (reproductive ability, germinating power, oil content, lipoxygenase enzyme activity, acid value, peroxide value, fatty acid composition, UV absorbance, colour, sensorial properties, as well as the protein content, amino acid composition, colour and the smell of the meal), but no aflatoxin production occurred. The findings offer a comprehensive picture on the multiple destructive effects of incorrect storage.
Authors:B. Nagy, J. Soós, B. Horvath, M. Kállay, B. Nyúl-Pühra and D. Nyitrai-Sárdy
During the ageing in barrels, the contact with the fine lees triggers several processes in wine. Lees has a reductive effect by absorbing dissolved oxygen and reducing the amount, which will remain in the wine. At present, minimizing the addition of sulphur dioxide is the trend in all viticultural areas. In this study, the effect of various sulphur dioxide levels was monitored in presence of the lees to determine which dose is appropriate to provide the protection of susceptible white wine against oxidation.
Without SO2 protection, the rH and redox potential changed slightly, so the level of dissolved oxygen seemed to be controlled during the ageing period by the lees, though the antioxidant effect of lees in itself was not appropriate to protect the polyphenol content from chemical oxidation, which led to considerable browning. With the addition of a lower amount of SO2 — 40 mg l2, the lees is already able to protect the white wine samples in all aspects.
Authors:Á. Tóth, E. Baka, Sz. Luzics, I. Bata-Vidács, I. Nagy, B. Bálint, R. Herczeg, F. Olasz, T. Wilk, T. Nagy, B. Kriszt, I. Nagy and J. Kukolya
Thermobifidas are thermophilic, aerobic, lignocellulose decomposing actinomycetes. The Thermobifida genus includes four species: T. fusca, T. alba, T. cellulosilytica, and T. halotolerans. T. fusca YX is the far best characterized strain of this taxon and several cellulases and hemicellulases have been cloned from it for industrial purposes targeting paper industry, biofuel, and feed applications. Unfortunately, sequence data of such enzymes are almost exclusively restricted to this single species; however, we demonstrated earlier by zymography that other T. alba and T. cellulosilytica strains encode the same enzyme sets. Recently, the advances in whole genome sequencing by the use of next generation genomics platforms accelerated the selection process of valuable hydrolases from uncharacterized bacterial species for cloning purposes. For this purpose T. cellulosilytica TB100T type strain was chosen for de novo genome sequencing. We have assembled the genome of T. cellulosilytica strain TB100T into 168 contigs and 19 scaffolds, with reference length of 4 327 869 bps, 3 589 putative coding sequences, 53 tRNAs, and 4 rRNAs. The analysis of the annotated genome revealed the existence of 27 putative hydrolases belonging to 14 different glycoside hydrolase (GH) families. The investigation of identified, cloned, and heterologously multiple cellulases, mannanases, xylanases, and amylases may result in industrial applications beside gaining useful basic research related information.
Authors:J. B.Nagy, J. N. Coleman, A. Fonseca, A. Destrée, Z. Mekhalif, N. Moreau, L. Vast and J. Delhalle
Organic polymers -
carbon nanotubes nanocomposites are synthesized either by mechanical mixing of
the two components or by covalently linking the nanotubes to the matrix. The
various procedures will be overviewed and the determining factors will be
identified for the best mechanical properties of the composites. On the other
hand, it will be shown that for highest electrical conductivity much smaller
amounts of carbon nanotubes are needed if the nanotubes can be aligned. The
thermal conductivity of the nanocomposites will also be overviewed. Finally,
together with nanoclay particles, nanotubes are inducing remarkable flame
retardant properties in the nanocomposites materials.
Authors:A. Szabo, A. Fonseca, L. P. Biro, Z. Konya, I. Kiricsi, A. Volodin, C. Van Hasendonck and J. B.Nagy
Some recent results on
the synthesis of coiled carbon nanotubes (CNTs) are summarized. Several
supported catalysts can lead to the formation of coiled CNTs. Interestingly,
certain domains of the coil pitch and coil diameter are favoured, and two
“stability islands”are found in the 3D representation of the number of coiled
CNTs as a function of both coil pitch and coil diameter. It is emphasized that
these nanotubes are formed either by introducing pairs of five-membered ring -
seven-membered ring or by forming haeckelite structures. The coiled CNTs could
be used in nanocomposite reinforcement as well as special sensors based on
their remarkable mechanical and electrical properties.