Optimization of bioprocess for production of copper-enriched biomass of industrially important microorganism Saccharomyces cerevisiae

The production of Saccharomyces cerevisiae cells enriched with copper and the effects of adding copper ions to different media on yeast cell growth and ethanol production were studied. In the media Cu(2+) concentrations of up to 0.094 mM had no effect on alcoholic fermentation, whereas higher Cu(2+) concentrations markedly decreased yeast cell growth rate and ethanol production. Under static conditions, the maximum amounts of copper uptake (i.e., 1.16 mg/g, 1.2 mg/g and 0.81 mg/g dry matter yeast biomass for glucose, sucrose and molasses media, respectively) were obtained after 8 h of fermentation, whereas under dynamic conditions smaller amounts of copper uptake (i.e., 0.98 mg/g, 1.02 mg/g and 0.7 mg/g dry matter yeast biomass for glucose, sucrose and molasses media, respectively) were obtained after 6 h of fermentation.     

Defining a strategy for chemical imaging of industrial pharmaceutical samples on Raman line-mapping and global illumination instruments

The performance of line-mapping and global illumination Raman systems for two pharmaceutical tablets and a powder blend are assessed in this study. The chemical images were obtained from the placebo, real tablets, and powder blend by using x20, x50, and x100 objectives, as well as via the (pseudo) confocal set-up. The chemical images were produced via univariate wavenumbers and as re-folded principal component (PC) scores (known as score images). In most cases it was easy to image two or three major components of the tablets directly, while the minor components were only imaged via PC scores. The active pharmaceutical ingredients (APIs) were located relatively easily even if present in quite low concentrations (less than 1%) owing to the high Raman scattering coefficients of these materials. The strength of the Raman signal of the API makes it almost ubiquitous in the chemical images of real tablets. Thorough discussion is given on the strategies used to produce chemical images, the prospects of making composite images of all components present in the tablets, and the effects of packing density with relation to the diffusion of the excitation laser light inside the sample. The strengths and weaknesses of the Raman imaging techniques used are emphasized and suggestions are given regarding which instrument is preferable with respect to the goal of the experiment and material under study. For example, mapping technology is preferred for analyzing minor components, while the global illumination approach is recommended for imaging of spatially isolated strong Raman scatterers.     

Estimation of sedimentation rate in the Middle and South Adriatic Sea using 137Cs

(137)Cs activity concentrations were studied in the sediment profiles collected at five locations in the Middle and South Adriatic. In the sediment profiles collected from the South Adriatic Pit, the deepest part of the Adriatic Sea, two (137)Cs peaks were identified. The peak in the deeper layer was attributed to the period of intensive atmospheric nuclear weapon tests (early 1960s), and the other to the Chernobyl nuclear accident (1986). Those peaks could be used to estimate sedimentation rates by relating them to the respective time periods. Grain-size analysis showed no changes in vertical distribution through the depth of the sediment profile, and these results indicate uniform sedimentation, as is expected in deeper marine environments. It was not possible to identify respective peaks on more shallow locations due to disturbance of the seabed either by trawlers (locations Palagru?a and Jabuka) or by river sediment (location Albania). The highest sedimentation rates were found in Albania (～4 mm y(-1)) and Jabuka (3.1 mm y(-1)). For Palagru?a, the sedimentation rate was estimated to be 1.8 mm y(-1), similar to the South Adriatic Pit where the sedimentation rate was estimated to be 1.8±0.5 mm y(-1). Low sedimentation rates found for the Middle and South Adriatic Sea are consistent with previously reported results for the rest of the Mediterranean.     

Raman mapping of low-content active-ingredient pharmaceutical formulations. part II: statistically optimized sampling for detection of less than 1% of an active pharmaceutical ingredient

Several tablets are prepared with two forms of an active pharmaceutical ingredient (API) of which one (less than 1% w/w) is considered undesirable. The presence of this component is tested for by Raman microscopy in a series of mapping experiments. These experiments are conducted with a statistically based sampling routine in which the number of spectra to collect across the whole surface of a tablet is set so as to theoretically ensure spectral detection of the low-concentration form. Such experiments are then repeated a number of times to achieve approximately 95% confidence that the strictly limited number of sampling points suffice to detect the low-concentration form and that Raman microscopy is technically a reliable method for analytical analysis of this type.     

Composition of the Defensive Secretion in Three Species of European Millipedes

Three European julid species, Cylindroiulus boleti, Leptoiulus trilineatus, and Megaphyllum bosniense, secrete mixtures of up to 12 different quinones. The major components in these species are 2-methoxy-3-methyl-1,4-benzoquinone and 2-methyl-1,4-benzoquinone. 2-Methoxy-5-methylhydroquinone is detected for the first time in the Class Diplopoda. 2-Hydroxy-3-methyl-1,4-benzoquinone, 2,3-dimethoxyhydroquinone, 2-methyl-3,4-methylendioxyphenol, and 2,3-dimethoxy-5-methylhydroquinone are registered for the first time in representatives of the family Julidae. The similar chemical composition of defense secretions in all analyzed European julids and Pacific spirobolids supports the idea of the chemical consistency of defensive compounds in juliform millipedes.     

Oily water treatment using a new steady-state fiber-bed coalescer

This study was concerned with the possibility of oil separation from two heavily polluted wastewater types: formation water and wastewater from hardening shop, using bed a newly developed coalescer. Experiments were carried out using original wastewaters and an artificial model wastewater. Results obtained for seven samples of formation water of very different quality showed that the water properties had no significant effect on bed coalescence efficiency. In contrast to this, crude oil properties strongly influenced steady-state bed coalescence. In the treatment of hardening oily wastewater in situ during a 4-month period oil concentration in the effluent was less than 20mg/l in all experiments. It appeared that oil concentration and water quality had no effect on bed separation efficiency. Special design of the coalescer and use of two filter materials ensured its good performance. Namely, the pipe-in-pipe construction provided the water orientation change several times while passing through the unit, making inertia one of dominant separation mechanisms.     

Wear Behavior of Composites Based on ZA-27 Alloy Reinforced by Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Particles Under Dry Sliding Condition

In present study, the effect of Al₂O₃ particle reinforcement on the sliding behavior of ZA-27 alloy composites was investigated. The composites with 3, 5, and 10 wt% of Al₂O₃ particles were produced by the compocasting procedure. Tribological properties of unreinforced alloy and composite were studied, using block-on-disk tribometer under unlubricated sliding conditions at different specific loads and sliding speeds. The worn surfaces of samples were examined by the scanning electron microscopy (SEM). The test results revealed that those composite specimens exhibited significantly lower wear rate than the ZA-27 matrix alloy specimens in all combinations of applied loads and sliding speeds. The difference in the wear resistance of composite with respect to the matrix alloy, increased with the increase of the applied load/sliding speed and Al₂O₃ particle content. The highest degree of improvement of the ZA-27 alloy tribological behavior corresponded with change of the Al₂O₃ particles content from 3 to 5 wt%. At low sliding speed, moderate lower wear rate of the composites over that of the matrix alloy was noticed. This has been attributed to micro cracking tendency of the composites. Significantly reduced wear rate, experienced by the composite over that of the matrix alloy at the higher sliding speeds and loads, could be explained due to enhanced compatibility of matrix alloy with dispersoid phase and greater thermal stability of the composite in view of the presence of the dispersoid. Level of wear rate of tested ZA-27/Al₂O₃ samples pointed to the process of mild wear, which was primarily controlled by the formation and destruction of mechanical mixed layers (MMLs).