Cloning, characterization and functionality of the orotidine-5'-phosphate decarboxylase gene (URA3) of the glycolipid-producing yeast Candida bombicola

Candida bombicola is a yeast species known to synthesize glycolipids. Although these glycolipids find several industrial, cosmetic and pharmaceutical applications, very little is known about the genetics of C. bombicola. A basic tool for genetic study and modification is the availability of an efficient transformation and selection system. In order to develop such a system, the URA3 gene of Candida bombicola was isolated using degenerate PCR and genomic walking. The gene encodes for an enzyme of 262 amino acids and shows high homology with the known orotidine-5'-phosphate decarboxylases of several other yeast species. The functionality of the gene was proved by complementation of a URA3-negative Saccharomyces cerevisiae strain.     

Decontamination of soil washing wastewater using solar driven advanced oxidation processes

Decontamination of soil washing wastewater was performed using two different solar driven advanced oxidation processes (AOPs): the photo-Fenton reaction and the cobalt/peroxymonosulfate/ultraviolet (Co/PMS/UV) process. Complete sodium dodecyl sulphate (SDS), the surfactant agent used to enhance soil washing process, degradation was achieved when the Co/PMS/UV process was used. In the case of photo-Fenton reaction, almost complete SDS degradation was achieved after the use of almost four times the actual energy amount required by the Co/PMS/UV process. Initial reaction rate in the first 15 min (IR₁₅) was determined for each process in order to compare them. Highest IR₁₅ value was determined for the Co/PMS/UV process (0.011 mmol/min) followed by the photo-Fenton reaction (0.0072 mmol/min) and the dark Co/PMS and Fenton processes (IR₁₅ = 0.002 mmol/min in both cases). Organic matter depletion in the wastewater, as the sum of surfactant and total petroleum hydrocarbons present (measured as chemical oxygen demand, COD), was also determined for both solar driven processes. It was found that, for the case of COD, the highest removal (69%) was achieved when photo-Fenton reaction was used whereas Co/PMS/UV process yielded a slightly lower removal (51%). In both cases, organic matter removal achieved was over 50%, which can be consider proper for the coupling of the tested AOPs with conventional wastewater treatment processes such as biodegradation.     

Phage therapy and phage control: to be revisited urgently!!

Phage therapy has been a valuable asset since the 1920s to deal with pathogenic bacterial infections, and has been practised ever since, especially in the former Soviet Union and in eastern Europe. The western world remained sceptical and resorted to the widespread use of antibiotics as soon as they became available. Now that antibiotic resistance among pathogenic bacteria has spread alarmingly and no really new antibiotic compounds are in the pipeline, renewed attention should be directed to the use of phages as antimicrobials in medicine as well as in the health and the agro‐food sector. The history of early phage use, its successes and problems and the current developments in phage research, production and applications in phage control and therapy are critically reviewed in this context. © 2013 Society of Chemical Industry     

Multifaceted Target Specificity Analysis as a Tool in Antimicrobial Drug Development: Type III Pantothenate Kinases as a Case Study

The research and development of a new antimicrobial drug using a target-based approach raises the question of whether any resulting hits will also show activity against the homologous target in other closely related organisms. While an assessment of the similarities of the predicted interactions between the identified inhibitor and the various targets is an obvious first step in answering this question, no clear and consistent framework has been proposed for how this should be done. Here we developed Multifaceted Target Specificity Analysis (MTSA) and applied it to type III pantothenate kinase (PanK_III) – an essential enzyme required for coenzyme A biosynthesis in a wide range of pathogenic bacteria – as a case study to establish if targeting a specific organism's PanK_III would lead to a narrow- or broad-spectrum agent. We propose that MTSA is a useful tool and aid for directing new target-based antimicrobial drug development initiatives.     

Singularity-Free Frame Fields for Line Drawing Vectorization

State-of-the-art methods for line drawing vectorization rely on generated frame fields for robust direction disambiguation, with each of the two axes aligning to different intersecting curve tangents around junctions. However, a common source of topological error for such methods are frame field singularities. To remedy this, we introduce the first frame field optimization framework guaranteed to produce singularity-free fields aligned to a line drawing. We first perform a convex solve for a roughly-aligned orthogonal frame field (cross field), and then comb away its internal singularities with an optimal transport–based matching. The resulting topology of the field is strictly maintained with the machinery of discrete trivial connections in a final, non-convex optimization that allows non-orthogonality of the field, improving smoothness and tangent alignment. Our frame fields can serve as a drop-in replacement for frame field optimizations used in previous work, improving the quality of the final vectorizations.     

Assessment of Brazilian consumers' perception about the presence of stabilisers in UHT milk: A study using virtual focus groups

Several countries use stabilisers in the product to avoid undesirable alterations, such as aggregation/gelation of proteins after thermal processing of UHT milk. Brazilian consumers' perception of these additives was investigated using virtual focus groups. Several relevant factors to the decision of consumers were elicited. The results show that most consumers do not have the habit of reading the UHT milk label and demonstrate a lack of knowledge about using stabilisers in UHT milk, even confusing it with preservatives. It is noted that the dairy sector must improve its communication strategies for UHT milk consumers.     

Processing and characterization of carbon nanofibers obtained from PAN/lignin blends processed by electrospinning

Blankets based on blends with different PAN/lignin ratios (10 and 50% wt. of lignin) were processed via electrospinning. Then, the blankets obtained were thermally treated in order to produce samples of carbon nanofibers. The thermo-oxidative stabilization parameters were defined based on a 2³-factorial design. The samples, after stabilization, were analyzed by differential scanning calorimetry (DSC), thermogravimetry (TGA), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR) techniques. Based on the results, the best parameters for the stabilization of electrospun, blankets were selected, and subsequently, the most adequate carbonization parameters were established to obtain the carbon blankets. The carbonized blankets were characterized for electrical conductivity by impedance spectroscopy, chemical structure (Raman and FT-IR spectroscopies), crystallographic ordering by X-ray diffraction (XRD), and morphology (SEM). The results showed the feasibility of producing carbon blankets based on PAN/lignin blends. However, carbonized blankets showed low carbon yield (10–56%) and a decrease of up to 70% in fiber diameter. XRD and Raman spectroscopy showed that the structural ordering of carbon blankets presents different values according to the heat treatment parameters used (45–57%) and a poorly ordered structure, indicated by the ID/IG ratio.