Nitrogen – a guide element in the bioconversion of lignocellulosics

Several balanced experiments of protein enrichment have shown that if ammonia is the sole N source in the bioconversion of lignocellulosics, significant data on the process can either be received from the N consumption determined, or from fixed organic nitrogen. Nitrogen can be a guide element for such data as cell biomass, utilized substrate, degree of bioconversion, specific substrate consumption coefficient, crude protein and crude protein yield, which are all necessary for the classification of fungi and substrates as well as for process characterization and optimization.     

Improvement of the nutritional value of rye products by solid-state fermentation with fusaria

The use of some cereals in animal nutrition, e.g. rye, is limited because of some constituents. By solid-state fermentation using selected Fusaria it is possible to enhance the nutrition value and to enrich the fermented material with free and essential amino acids and vitamins. The fermentation method is described and the results of analytical assays are discussed.     

Ultrasonographic contrast-agent imaging of sub-millimeter vessel structures with spatial compounding: in vitro analyses.

In clinical diagnostics, ultrasonographic contrast-agent imaging gives access to medical parameters such as perfusion and vascularization. In addition to the artifacts that are typical for ultrasonic imaging, e.g., speckle noise and depth-dependent sensitivity and resolution, contrast-agent imaging shows more pronounced depth dependence and may suffer from shadowing artifacts that arise from high attenuation of the ultrasound waves by the contrast agent at high concentrations. By imaging an object from different viewing angles in one 2D image plane and summing the images obtained (spatial compounding), image quality can be increased and artifacts can be suppressed. In the present study, we combined both techniques to overcome the limitations of contrast-agent imaging. We used a commercially available ultrasound scanner and a custom-made high-precision mechanical system to rotate the ultrasound transducer fully around the object under investigation. Using this set-up, ultrasound data were acquired in reflection mode to generate a 360 degrees compound scan of a flow-mimicking phantom supplied with contrast agent.     

Effect of temperature and temperature fluctuation on thermophilic anaerobic digestion of cattle manure

The influence of temperature, 50 and 60 degrees C, at hydraulic retention times (HRTs) of 20 and 10 days, on the performance of anaerobic digestion of cow manure has been investigated in completely stirred tank reactors (CSTRs). Furthermore, the effect of both daily downward and daily upward temperature fluctuations has been studied. In the daily downward temperature fluctuation regime the temperatures of each reactor was reduced by 10 degrees C for 10 h while in the daily upward fluctuation regime the temperature of each reactor was increased 10 degrees C for 5 h. The results show that the methane production rate at 60 degrees C is lower than that at 50 degrees C at all experimental conditions of imposed HRT except when downward temperature fluctuations were applied at an HRT of 10 days. It also was found that the free ammonia concentration not only affects the acetate-utilising bacteria but also the hydrolysis and acidification process. The upward temperature fluctuation affects the maximum specific methanogenesis activity more severely as compared to imposed downward temperature fluctuations. The results clearly reveal the possibility of using available solar energy at daytime to heat up the reactor(s) without the need of heat storage during nights, especially at an operational temperature of 50 degrees C and at a 20 days HRT, and without the jeopardising of the overheating.     

Regulation of Presynaptic Anchoring of the Scaffold Protein Bassoon by Phosphorylation-Dependent Interaction with 14-3-3 Adaptor Proteins

The proper organization of the presynaptic cytomatrix at the active zone is essential for reliable neurotransmitter release from neurons. Despite of the virtual stability of this tightly interconnected proteinaceous network it becomes increasingly clear that regulated dynamic changes of its composition play an important role in the processes of synaptic plasticity. Bassoon, a core component of the presynaptic cytomatrix, is a key player in structural organization and functional regulation of presynaptic release sites. It is one of the most highly phosphorylated synaptic proteins. Nevertheless, to date our knowledge about functions mediated by any one of the identified phosphorylation sites of Bassoon is sparse. In this study, we have identified an interaction of Bassoon with the small adaptor protein 14-3-3, which depends on phosphorylation of the 14-3-3 binding motif of Bassoon. In vitro phosphorylation assays indicate that phosphorylation of the critical Ser-2845 residue of Bassoon can be mediated by a member of the 90-kDa ribosomal S6 protein kinase family. Elimination of Ser-2845 from the 14-3-3 binding motif results in a significant decrease of Bassoon''s molecular exchange rates at synapses of living rat neurons. We propose that the phosphorylation-induced 14-3-3 binding to Bassoon modulates its anchoring to the presynaptic cytomatrix. This regulation mechanism might participate in molecular and structural presynaptic remodeling during synaptic plasticity.     

Jasmonate-induced lipid peroxidation in barley leaves initiated by distinct 13-LOX forms of chloroplasts

In addition to a previously characterized 13-lipoxygenase of 100 kDa encoded by LOX2:Hv:1 [V?r?s et al., Eur. J. Biochem. 251 (1998), 36-44], two full-length cDNAs (LOX2:Hv:2, LOX2:Hv:3) were isolated from barley leaves (Hordeum vulgare cv. Salome) and characterized. Both of them encode 13-lipoxygenases with putative target sequences for chloroplast import. Immunogold labeling revealed preferential, if not exclusive, localization of lipoxygenase proteins in the stroma. The ultrastructure of the chloroplast was dramatically altered following methyl jasmonate treatment, indicated by a loss of thylakoid membranes, decreased number of stacks and appearance of numerous osmiophilic globuli. The three 13-lipoxygenases are differentially expressed during treatment with jasmonate, salicylate, glucose or sorbitol. Metabolite profiling of free linolenic acid and free linoleic acid, the substrates of lipoxygenases, in water floated or jasmonate-treated leaves revealed preferential accumulation of linolenic acid. Remarkable amounts of free 9- as well as 13-hydroperoxy linolenic acid were found. In addition, metabolites of these hydroperoxides, such as the hydroxy derivatives and the respective aldehydes, appeared following methyl jasmonate treatment. These findings were substantiated by metabolite profiling of isolated chloroplasts, and subfractions including the envelope, the stroma and the thylakoids, indicating a preferential occurrence of lipoxygenase-derived products in the stroma and in the envelope. These data revealed jasmonate-induced activation of the hydroperoxide lyase and reductase branch within the lipoxygenase pathway and suggest differential activity of the three 13-lipoxygenases under different stress conditions.     

Expression of cucumber lipid-body lipoxygenase in transgenic tobacco: lipid-body lipoxygenase is correctly targeted to seed lipid bodies

 A particular isoform of lipoxygenase (LOX, EC 1.13.11.12) localized on lipid bodies has been shown by earlier investigations to play a role during seed germination in initiating the mobilization of triacylglycerols. On lipid bodies of germinating cucumber (Cucumis sativus L.) seedlings, the modification of linoleoyl moieties by this LOX precedes the hydrolysis of the ester bonds. We analyzed the expression and intracellular location of this particular LOX form in leaves and seeds of tobacco (Nicotiana tabacum L.) transformed with one construct coding for cucumber lipid-body LOX and one construct coding for cucumber LOX fused with a hemagglutinin epitope. In both tissues, the amount of lipid-body LOX was clearly detectable. Biochemical analysis revealed that in mature seeds the foreign LOX was targeted to lipid bodies, and the preferred location of the LOX on lipid bodies was verified by immunofluorescence microscopy. Cells of the endosperm and of the embryo exhibited fluorescence based on the immunodecoration of LOX protein whereas very weak fluorescent label was visible in seeds of untransformed control plants. Further cytochemical analysis of transformed plants showed that the LOX protein accumulated in the cytoplasm when green leaves lacking lipid bodies were analyzed. Increased LOX activity was shown in young leaves of transformed plants by an increase in the amounts of endogenous (2E)-hexenal and jasmonic acid. Received: 9 August 1999 / Accepted: 28 September 1999     

Using a side‐selective fyke net barrier to research fish assemblages in the transitional and transboundary waters of the Vistula Lagoon,southern Baltic

The natural and territorial conditions of the Vistula Lagoon render it difficult to perform repeatable and representative investigations of fish assemblages. The changeability of hydro‐meteorological conditions (wind strength and direction), hydrological conditions (shallowness, the thickness of bottom sediments, submerged barriers, wavy motion) and the social and transboundary conditions mean that most standard monitoring methods and fish migration studies are either impossible to apply or produce unsatisfactory results. This current work presents the results of long‐term observations of fisheries deploying a side‐selective fyke‐net barrier. The fishing gear was deployed parallel to the border in the Vistula Lagoon in order to determine the difference in the movement of fish from the Polish and Russian sides of the lagoon. Thanks to the co‐operation with fishermen, data was collected from catches during the 1995–2002 period; this permitted the identification of variations in relative abundance and the dominant direction of fish migrations during the fishing season. The highest statistically significant differences between the fishing results on either side of the barrier were noted in the autumn months of September and October.     

Small animal micro-CT colonography

Microcomputed tomography colonography (mCTC) is a new method for detecting colonic tumors in living animals and estimating their volume, which allows investigators to determine the spontaneous fate of individually annotated tumors as well as their response to chemotherapeutics. This imaging platform was developed using the Min mouse, but is applicable to any murine model of human colorectal cancer. MicroCT is capable of 20 micron resolution, however, 100 microns is sufficient for this application. Scan quality is primarily dependent on animal preparation with the most critical parameters being proper anesthesia, bowel cleansing, and sufficient insufflation. The detection of colonic tumors is possible by both 2D and 3D rendering of image data. Tumor volume is estimated using a semi-automated five-step process which is based on three algorithms within the Amira software package. The estimates are precise, accurate and reproducible enabling changes in volume as small as 16% to be readily observed. Confirmation of mCTC observations by gross examination and histology is sometimes useful in this otherwise non-invasive protocol. Finally, mCTC is compared to other newly developed small animal imaging platforms including microMRI and microoptical colonoscopy. A major advantage of these platforms is that investigators can be perform longitudinal studies, which often have much greater statistical power than traditional cross-sectional studies; consequently, fewer animals are required for testing.