Encapsulation of Benzaldehyde Produced by the Eco-Friendly Degradation of Amygdalin in the Apricot Kernel Debitterizing Wastewater.

In order to fully utilize the by-products of apricot kernel-debitterizing and address the chemical instability of benzaldehyde in the food industry, benzaldehyde was first prepared by adding the apricot kernel powder to degrade the amygdalin present in the apricot kernel-debitterizing water. Subsequently, ß-cyclodextrin was employed to encapsulate the benzaldehyde, and its encapsulation efficacy was evaluated through various techniques including Fourier transform infrared spectroscopy, thermogravimetric analysis, release kinetics fitting inhibitory effect and the effect on Botrytis cinerea. Finally, the encapsulation was explored via molecular docking and molecular dynamics simulations. The results indicate that the optimal preparation conditions for the benzaldehyde were 1.8 h, 53 °C and pH 5.8, and the encapsulation of benzaldehyde with ß-cyclodextrin (wall-core ratio of 5:1, mL/g) has been verified by the deceleration in the release rate, the enhanced thermal stability and the prolonged inhibition effect against Botrytis cinerea. The encapsulation proceeded spontaneously without steric hindrance in the simulation, which led to a reduction in the hydrophobic cavity of ß-cyclodextrin. In conclusion, the amygdalin in the debitterizing wastewater can be degraded in an eco-friendly way to produce benzaldehyde by adding apricot kernel powder, which contains ß-glucosidase; the encapsulation of benzaldehyde is stable, thus enhancing the utilization of amygdalin in the debitterizing wastewater of apricot kernels.

The state-of-the-art research of the application of ultrasound to winemaking: A critical review.

As a promising non-thermal physical technology, ultrasound has attracted extensive attention in recent years, and has been applied to many food processing operation units, such as involving filtration, freezing, thawing, sterilization, cutting, extraction, aging, etc. It is also widely used in the processing of meat products, fruits and vegetables, and dairy products. With regard to its application in winemaking, most of the studies available in the literature are focused on the impact of ultrasound on a certain characteristic of wine, lacking of systematic sorting of these literatures. This review systematically summarizes and explores the current achievements and problems of the application of ultrasound to the different stages of winemaking, including extraction, fermentation, aging and sterilization. Summarizing the advantages and disadvantages of ultrasound application in winemaking and its development in future development.

Interconnected Set of Enzymes Provide Lysine Biosynthetic Intermediates and Ornithine Derivatives as Key Precursors for the Biosynthesis of Bioactive Secondary Metabolites.

Bacteria, filamentous fungi, and plants synthesize thousands of secondary metabolites with important biological and pharmacological activities. The biosynthesis of these metabolites is performed by networks of complex enzymes such as non-ribosomal peptide synthetases, polyketide synthases, and terpenoid biosynthetic enzymes. The efficient production of these metabolites is dependent upon the supply of precursors that arise from primary metabolism. In the last decades, an impressive array of biosynthetic enzymes that provide specific precursors and intermediates leading to secondary metabolites biosynthesis has been reported. Suitable knowledge of the elaborated pathways that synthesize these precursors or intermediates is essential for advancing chemical biology and the production of natural or semisynthetic biological products. Two of the more prolific routes that provide key precursors in the biosynthesis of antitumor, immunosuppressant, antifungal, or antibacterial compounds are the lysine and ornithine pathways, which are involved in the biosynthesis of ß-lactams and other non-ribosomal peptides, and bacterial and fungal siderophores. Detailed analysis of the molecular genetics and biochemistry of the enzyme system shows that they are formed by closely related components. Particularly the focus of this study is on molecular genetics and the enzymatic steps that lead to the formation of intermediates of the lysine pathway, such as α-aminoadipic acid, saccharopine, pipecolic acid, and related compounds, and of ornithine-derived molecules, such as N5-Acetyl-N5-Hydroxyornithine and N5-anhydromevalonyl-N5-hydroxyornithine, which are precursors of siderophores. We provide evidence that shows interesting functional relationships between the genes encoding the enzymes that synthesize these products. This information will contribute to a better understanding of the possibilities of advancing the industrial applications of synthetic biology.

Potential of Near-Infrared Spectroscopy for the Determination of Olive Oil Quality.

The analysis of the physico-chemical parameters of quality of olive oil is still carried out in laboratories using chemicals and generating waste, which is relatively costly and time-consuming. Among the various alternatives for the online or on-site measurement of these parameters, the available literature highlights the use of near-infrared spectroscopy (NIRS). This article intends to comprehensively review the state-of-the-art research and the actual potential of NIRS for the analysis of olive oil. A description of the features of the infrared spectrum of olive oil and a quick explanation of the fundamentals of NIRS and chemometrics are also included. From the results available in the literature, it can be concluded that the four most usual physico-chemical parameters that define the quality of olive oils, namely free acidity, peroxide value, K232, and K270, can be measured by NIRS with high precision. In addition, NIRS is suitable for the nutritional labeling of olive oil because of its great performance in predicting the contents in total fat, total saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids in olive oils. Other parameters of interest have the potential to be analyzed by NIRS, but the improvement of the mathematical models for their determination is required, since the errors of prediction reported so far are a bit high for practical application.

Molecular Mechanisms of Phosphate Sensing, Transport and Signalling in Streptomyces and Related Actinobacteria.

: Phosphorous, in the form of phosphate, is a key element in the nutrition of all living beings. In nature, it is present in the form of phosphate salts, organophosphates, and phosphonates. Bacteria transport inorganic phosphate by the high affinity phosphate transport system PstSCAB, and the low affinity PitH transporters. The PstSCAB system consists of four components. PstS is the phosphate binding protein and discriminates between arsenate and phosphate. In the Streptomyces species, the PstS protein, attached to the outer side of the cell membrane, is glycosylated and released as a soluble protein that lacks its phosphate binding ability. Transport of phosphate by the PstSCAB system is drastically regulated by the inorganic phosphate concentration and mediated by binding of phosphorylated PhoP to the promoter of the PstSCAB operon. In Mycobacterium smegmatis, an additional high affinity transport system, PhnCDE, is also under PhoP regulation. Additionally, Streptomyces have a duplicated low affinity phosphate transport system encoded by the pitH1-pitH2 genes. In this system phosphate is transported as a metal-phosphate complex in simport with protons. Expression of pitH2, but not that of pitH1 in Streptomyces coelicolor, is regulated by PhoP. Interestingly, in many Streptomyces species, three gene clusters pitH1-pstSCAB-ppk (for a polyphosphate kinase), are linked in a supercluster formed by nine genes related to phosphate metabolism. Glycerol-3-phosphate may be transported by the actinobacteria Corynebacterium glutamicum that contains a ugp gene cluster for glycerol-3-P uptake, but the ugp cluster is not present in Streptomyces genomes. Sugar phosphates and nucleotides are used as phosphate source by the Streptomyces species, but there is no evidence of the uhp gene involved in the transport of sugar phosphates. Sugar phosphates and nucleotides are dephosphorylated by extracellular phosphatases and nucleotidases. An isolated uhpT gene for a hexose phosphate antiporter is present in several pathogenic corynebacteria, such as Corynebacterium diphtheriae, but not in non-pathogenic ones. Phosphonates are molecules that contains phosphate linked covalently to a carbon atom through a very stable C-P bond. Their utilization requires the phnCDE genes for phosphonates/phosphate transport and genes for degradation, including those for the subunits of the C-P lyase. Strains of the Arthrobacter and Streptomyces genera were reported to degrade simple phosphonates, but bioinformatic analysis reveals that whole sets of genes for putative phosphonate degradation are present only in three Arthrobacter species and a few Streptomyces species. Genes encoding the C-P lyase subunits occur in several Streptomyces species associated with plant roots or with mangroves, but not in the laboratory model Streptomyces species; however, the phnCDE genes that encode phosphonates/phosphate transport systems are frequent in Streptomyces species, suggesting that these genes, in the absence of C-P lyase genes, might be used as surrogate phosphate transporters. In summary, Streptomyces and related actinobacteria seem to be less versatile in phosphate transport systems than Enterobacteria.

Production of Bio-Oils and Biochars from Olive Stones: Application of Biochars to the Esterification of Oleic Acid.

Olive stones are a by-product of the olive oil industry. In this work, the valorisation of olive stones through pyrolysis was attempted. Before pyrolysis, half of the samples were impregnated with sulphuric acid. Pyrolysis was carried out in a vertical tubular furnace with a ceramic support. The pyrolysis conditions assayed were: temperature between 400 and 600 °C, heating ramp between 5 and 20 °C∙min-1, and inert gas flow rate between 50 and 300 mL Ar∙min-1. Among them, temperature was the only parameter that influenced the pyrolysis product distribution. The most suitable temperature for obtaining biochar was 400 °C for both non-treated and pre-treated raw material, while for obtaining bio-oil, it was 600 °C for impregnated olive stones and 400 °C for the raw material. The impregnated olives stones led to bio-oils with much higher amounts of high-added-value products such as levoglucosenone and catechol. Finally, the biochars were impregnated with sulphuric acid and assayed as biocatalysts for the esterification of oleic acid with methanol in a stirred tank batch reactor at 60 °C for 30 min. Biochars from non-treated olive stones, which had lower specific surfaces, led to higher esterification yields (up to 96.2%).

Determination of pectin content in orange peels by near infrared hyperspectral imaging.

Pectin has several purposes in the food and pharmaceutical industry making its quantification important for further extraction. Current techniques for pectin quantification require its extraction using chemicals and producing residues. Determination of pectin content in orange peels was investigated using near infrared hyperspectral imaging (NIR-HSI). Hyperspectral images from orange peel (140 samples) with different amounts of pectin were acquired in the range of 900-2500 nm, and the spectra was used for calibration models using multivariate statistical analyses. Principal component analysis (PCA) and linear discriminant analysis (LDA) showed better results considering three groups: low (0-5%), intermediate (10-40%) and high (50-100%) pectin content. Partial least squares regression (PLSR) models based on full spectra showed higher precision (R2 > 0.93) than those based on few selected wavelengths (R2 between 0.92 and 0.94). The results demonstrate the potential of NIR-HSI to quantify pectin content in orange peels, providing a valuable technique for orange producers and processing industries.

Metal Accumulation by Jatropha curcas L. Adult Plants Grown on Heavy Metal-Contaminated Soil.

Jatropha curcas has the ability to phytoextract high amounts of heavy metals during its first months just after seeding. Notwithstanding, there is scarce information about metal uptake by adult J. curcas plants. To shed light on this issue, 4-year-old J. curcas L. plants were planted in a soil mixture of peat moss and mining soil (high metals content), and the biomass growth and metal absorption during 90 days were compared with those of plants growing in peat moss. The main metal found in the mining soil was Fe (31985 mg kg-1) along with high amounts of As (23717 mg kg-1). After the 90-day phytoremediation, the plant removed 29% of Fe and 44% of As from the soil mixture. Results revealed that J. curcas L. translocated high amounts of metals to its aerial parts, so that translocation factors were much higher than 1. Because of the high translocation and bioaccumulation factors obtained, J. curcas L. can be regarded as a hyperaccumulator plant. Despite the great capacity of J. curcas L. to phytoremediate heavy-metal-contaminated soils, the main drawback is the subsequent handling of the metal-contaminated biomass, although some potential applications have been recently highlighted for this biomass.

Thermal Analysis of a Magnetic Brake Using Infrared Techniques and 3D Cell Method with a New Convective Constitutive Matrix.

In this work we analyse the temperature distribution in a conductor disk in transitory regime. The disk is in motion in a stationary magnetic field generated by a permanent magnet and so, the electric currents induced inside it generate heat. The system acts as a magnetic brake and is analysed using infrared sensor techniques. In addition, for the simulation and analysis of the magnetic brake, a new thermal convective matrix for the 3D Cell Method (CM) is proposed. The results of the simulation have been verified by comparing the numerical results with those obtained by the Finite Element Method (FEM) and with experimental data obtained by infrared technology. The difference between the experimental results obtained by infrared sensors and those obtained in the simulations is less than 0.0459%.

Phytoremediation of highly contaminated mining soils by Jatropha curcas L. and production of catalytic carbons from the generated biomass.

This paper deals with the removal of heavy metals from marginal soil mixtures from the Cobre Las Cruces and Aznalcóllar mining areas containing high concentrations of metals (Cr, Fe, Ni, Cu, Zn, Cd, Hg, Pb and As) by means of phytoremediation using Jatropha curcas L., and the subsequent production of biocatalysts from the plant biomass. First, J. curcas L. was sowed in eight mixtures of these mining soils to study its adaption to these high-contaminated soils and its growth during 60 days in a greenhouse under conditions simulating the South of Spain's spring climate. Later, the most suitable soil mixtures for plant growth were used for 120-day phytoremediation under the same conditions. Heavy metal concentration in soils, roots, stems and leaves were measured by ICP-OES at the beginning, at the middle and at the end of the phytoremediation period, thus calculating the translocation and bioaccumulation factors. J. curcas L. was found to absorb great amounts of Fe (>3000 mg kg-1 plant) as well as notable amounts of Pb, Zn, Cu, Cr and Ni, and traces of As. Other metals with lower initial concentrations such as Cd, Hg and Sn were completely removed from soils. Finally, the plant biomass was subjected to pyrolysis to obtain catalytic biocarbons, assessing the optimal temperature for the pyrolytic process by means of thermogravimetric analysis and Raman spectroscopy.

Catabolism of phenylacetic acid in Penicillium rubens. Proteome-wide analysis in response to the benzylpenicillin side chain precursor.

Biosynthesis of benzylpenicillin in filamentous fungi (e.g. Penicillium chrysogenum - renamed as Penicillium rubens- and Aspergillus nidulans) depends on the addition of CoA-activated forms of phenylacetic acid to isopenicillin N. Phenylacetic acid is also detoxified by means of the homogentisate pathway, which begins with the hydroxylation of phenylacetic acid to 2-hydroxyphenylacetate in a reaction catalysed by the pahA-encoded phenylacetate hydroxylase. This catabolic step has been tested in three different penicillin-producing strains of P. rubens (P. notatum, P. chrysogenum NRRL 1951 and P. chrysogenum Wisconsin 54-1255) in the presence of sucrose and lactose as non-repressing carbon sources. P. chrysogenum Wisconsin 54-1255 was able to accumulate 2-hydroxyphenylacetate at late culture times. Analysis of the P. rubens genome showed the presence of several PahA homologs, but only Pc16g01770 was transcribed under penicillin production conditions. Gene knock-down experiments indicated that the protein encoded by Pc16g01770 seems to have residual activity in phenylacetic acid degradation, this catabolic activity having no effect on benzylpenicillin biosynthesis. Proteome-wide analysis of the Wisconsin 54-1255 strain in response to phenylacetic acid revealed that this molecule has a positive effect on some proteins directly related to the benzylpenicillin biosynthetic pathway, the synthesis of amino acid precursors and other important metabolic processes. SIGNIFICANCE: The adaptive response of Penicillium rubens to benzylpenicillin production conditions remains to be fully elucidated. This article provides important information about the molecular mechanisms interconnected with phenylacetate (benzylpenicillin side chain precursor) utilization and penicillin biosynthesis, and will contribute to the understanding of the complex physiology and adaptation mechanisms triggered by P. rubens (P. chrysogenum Wisconsin 54-1255) under benzylpenicillin production conditions.

Hyperspectral Imaging in Tandem with R Statistics and Image Processing for Detection and Visualization of pH in Japanese Big Sausages Under Different Storage Conditions.

The potential of hyperspectral imaging with wavelengths of 380 to 1000 nm was used to determine the pH of cooked sausages after different storage conditions (4 °C for 1 d, 35 °C for 1, 3, and 5 d). The mean spectra of the sausages were extracted from the hyperspectral images and partial least squares regression (PLSR) model was developed to relate spectral profiles with the pH of the cooked sausages. Eleven important wavelengths were selected based on the regression coefficient values. The PLSR model established using the optimal wavelengths showed good precision being the prediction coefficient of determination (Rp2 ) 0.909 and the root mean square error of prediction 0.035. The prediction map for illustrating pH indices in sausages was for the first time developed by R statistics. The overall results suggested that hyperspectral imaging combined with PLSR and R statistics are capable to quantify and visualize the sausages pH evolution under different storage conditions. PRACTICAL APPLICATION: In this paper, hyperspectral imaging is for the first time used to detect pH in cooked sausages using R statistics, which provides another useful information for the researchers who do not have the access to Matlab. Eleven optimal wavelengths were successfully selected, which were used for simplifying the PLSR model established based on the full wavelengths. This simplified model achieved a high Rp2 (0.909) and a low root mean square error of prediction (0.035), which can be useful for the design of multispectral imaging systems.

Self-control of the PHO regulon: the PhoP-dependent protein PhoU controls negatively expression of genes of PHO regulon in Streptomyces coelicolor.

Phosphate control of the biosynthesis of secondary metabolites in Streptomyces is mediated by the two component system PhoR-PhoP. Linked to the phoR-phoP cluster, and expressed in the opposite orientation, is a phoU-like encoding gene with low identity to the phoU gene of Escherichia coli. Expression of this phoU-like gene is strictly dependent on PhoP activation. We have isolated a PhoU-null mutant and used transcriptomic and RNA-sequencing (RNA-seq) procedures to identify its transcription start site and regulation. RNA-seq studies identified two transcription start sites, one upstream of phoU and the second upstream of the mptA gene. Whereas transcription of PhoU is entirely dependent on PhoP, expression of the downstream mtpA gene is only partially dependent on PhoP activation. The phoU mutant grows more slowly than the parental strain, sporulates poorly and the spores lack pigmentation. Production of actinorhodin and undecylprodigiosin decreased in the phoU mutant, indicating that PhoU has a positive modulating effect on production of these antibiotics. Indeed, transcriptional studies of expression of the actII-ORF4 and redD genes indicated that the PhoU protein activates expression of these antibiotic regulators. Using the glpQ1 promoter as in vivo reporter of the activity of the PHO regulon genes, we observed that expression of glpQ1 is negatively modulated by PhoU. These results were confirmed by reverse transcription-PCR studies of three genes of the PHO regulon; that is, glpQ1, pstS and phoR. In conclusion, PhoU acts as a negative modulator of expression of the PHO regulon genes and as phoU expression is strictly dependent on PhoP activation, this mechanism appears to work as a feed-back control mechanism (self-regulation).The Journal of Antibiotics advance online publication, 1 November 2017; doi:10.1038/ja.2017.130.

Effect of ultrasound on the interaction between (-)-epicatechin gallate and bovine serum albumin in a model wine.

Ultrasound is considered as a potential novel technique for improving the quality of some wines. In this paper, a model wine firstly was constructed with the standards of (-)-epicatechin gallate (ECG) and bovine serum albumin (BSA) as target compounds. Then, the experiments were conducted to investigate the effect of ultrasonic irradiation on the binding properties between ECG and BSA including quenching mechanism, binding parameters, binding forces, energy transfer distance and conformational changes determined by spectral analysis. The results indicate that ultrasound definitely has some regular effects on the binding interaction of BSA and ECG, and can induced the conformation variation of BSA in the simulated wine, which may suggest that the ultrasound might be employed to modify the wine organoleptic property by regulating the interaction between phenolic compounds and proteins from the autolysis of yeasts, since they are similar to the standards of ECG and BSA, respectively.

Physical Properties and Volatile Composition Changes of Cooked Sausages Stuffed in a New Casing Formulation Based in Surfactants and Lactic Acid During Long-Term Storage.

The objective of this research was to investigate the effects of different modified casings and storage time on the quality attributes of cooked sausages using principal component analysis (PCA) and discriminant analysis. The effects of modifying different casing treatments on sausages' color (L* , a* , b* ), pH, and texture (hardness, springiness, cohesion, gumminess, chewiness) after 36-d storage were estimated by PCA. According to the PCA, lightness at day 36 was correlated to sample stuffed in casing with treatment 2 (T2; soy lecithin concentration: 1:27.5, soy oil concentration: 1.25%, lactic acid concentration: 19.5 mL/kg NaCl [solid], residence time: 75 min). T2 sample can be distinguished from control sample at days 1, 8, 15, and 36 according to electronic nose system. DA was performed to determine possible different sample groups according to selected variables. Results showed that chewiness was the best discriminator for differentiating sausages stored for 15 d from other days. Chewiness and gumminess were able to discriminate sausages stuffed in casing with T2 from control sample. The relationships between modified concentrations and quality attributes of cooked sausages after 36-d storage were also established.

Casein phosphopeptides and CaCl2 increase penicillin production and cause an increment in microbody/peroxisome proteins in Penicillium chrysogenum.

Transport of penicillin intermediates and penicillin secretion are still poorly characterized in Penicillium chrysogenum (re-identified as Penicillium rubens). Calcium (Ca2+) plays an important role in the metabolism of filamentous fungi, and casein phosphopeptides (CPP) are involved in Ca2+ internalization. In this study we observe that the effect of CaCl2 and CPP is additive and promotes an increase in penicillin production of up to 10-12 fold. Combination of CaCl2 and CPP greatly promotes expression of the three penicillin biosynthetic genes. Comparative proteomic analysis by 2D-DIGE, identified 39 proteins differentially represented in P. chrysogenum Wisconsin 54-1255 after CPP/CaCl2 addition. The most interesting group of overrepresented proteins were a peroxisomal catalase, three proteins of the methylcitrate cycle, two aminotransferases and cystationine ß-synthase, which are directly or indirectly related to the formation of penicillin amino acid precursors. Importantly, two of the enzymes of the penicillin pathway (isopenicillin N synthase and isopenicillin N acyltransferase) are clearly induced after CPP/CaCl2 addition. Most of these overrepresented proteins are either authentic peroxisomal proteins or microbody-associated proteins. This evidence suggests that addition of CPP/CaCl2 promotes the formation of penicillin precursors and the penicillin biosynthetic enzymes in peroxisomes and vesicles, which may be involved in transport and secretion of penicillin. SIGNIFICANCE: Penicillin biosynthesis in Penicillium chrysogenum is one of the best characterized secondary metabolism processes. However, the mechanism by which penicillin is secreted still remains to be elucidated. Taking into account the role played by Ca2+ and CPP in the secretory pathway and considering the positive effect that Ca2+ exerts on penicillin production, the analysis of global protein changes produced after CPP/CaCl2 addition is very helpful to decipher the processes related to the biosynthesis and secretion of penicillin.

Biosynthetic gene clusters for relevant secondary metabolites produced by Penicillium roqueforti in blue cheeses.

Ripening of blue-veined cheeses, such as the French Bleu and Roquefort, the Italian Gorgonzola, the English Stilton, the Danish Danablu or the Spanish Cabrales, Picón Bejes-Tresviso, and Valdeón, requires the growth and enzymatic activity of the mold Penicillium roqueforti, which is responsible for the characteristic texture, blue-green spots, and aroma of these types of cheeses. This filamentous fungus is able to synthesize different secondary metabolites, including andrastins, mycophenolic acid, and several mycotoxins, such as roquefortines C and D, PR-toxin and eremofortins, isofumigaclavines A and B, and festuclavine. This review provides a detailed description of the main secondary metabolites produced by P. roqueforti in blue cheese, giving a special emphasis to roquefortine, PR-toxin and mycophenolic acid, and their biosynthetic gene clusters and pathways. The knowledge of these clusters and secondary metabolism pathways, together with the ability of P. roqueforti to produce beneficial secondary metabolites, is of interest for commercial purposes.

Optimization of Pyrogallol Autoxidation Conditions and Its Application in Evaluation of Superoxide Anion Radical Scavenging Capacity for Four Antioxidants.

In this study, some factors influencing pyrogallol autoxidation, including EDTA, temperature, and solvent, were systematically investigated to improve its feasibility in the evaluation of antioxidants for the first time. Subsequently, the improved pyrogallol autoxidation conditions were used to assess the superoxide anion scavenging activity (SASA) of four commonly used antioxidants, namely, ascorbic acid, rutin, catechin, and gallic acid, by both the reaction rate method and the terminated method. The results indicate that pyrogallol autoxidation could be successfully used to determine the antioxidant capacity of ascorbic acid and rutin, which correspondingly suggests the feasibility of its use to measure the superoxide anion radical scavenging activity of polysaccharides and flavonols, because these compounds have a similar basic structural unit as ascorbic acid and rutin, respectively. Unexpectedly, however, pyrogallol autoxidation cannot be used to evaluate the SASA of catechin and gallic acid, although their good antioxidant capacity was confirmed by the 1,1-diphenyl-2-picrylhydrazyl assay. Together, these results suggest the importance of noting the conditions used for pyrogallol autoxidation when assessing the SASA of targeted compounds.

Free radical generation induced by ultrasound in red wine and model wine: An EPR spin-trapping study.

Direct evidence for the formation of 1-hydroxylethyl radicals by ultrasound in red wine and air-saturated model wine is presented in this paper. Free radicals are thought to be the key intermediates in the ultrasound processing of wine, but their nature has not been established yet. Electron paramagnetic resonance (EPR) spin trapping with 5,5-dimethyl-l-pyrrolin N-oxide (DMPO) was used for the detection of hydroxyl free radicals and 1-hydroxylethyl free radicals. Spin adducts of hydroxyl free radicals were detected in DMPO aqueous solution after sonication while 1-hydroxylethyl free radical adducts were observed in ultrasound-processed red wine and model wine. The latter radical arose from ethanol oxidation via the hydroxyl radical generated by ultrasound in water, thus providing the first direct evidence of the formation of 1-hydroxylethyl free radical in red wine exposed to ultrasound. Finally, the effects of ultrasound frequency, ultrasound power, temperature and ultrasound exposure time were assessed on the intensity of 1-hydroxylethyl radical spin adducts in model wine.

PcFKH1, a novel regulatory factor from the forkhead family, controls the biosynthesis of penicillin in Penicillium chrysogenum.

Penicillin biosynthesis in Penicillium chrysogenum (re-identified as Penicillium rubens) is a good example of a biological process subjected to complex global regulatory networks and serves as a model to study fungal secondary metabolism. The winged-helix family of transcription factors recently described, which includes the forkhead type of proteins, is a key type of regulatory proteins involved in this process. In yeasts and humans, forkhead transcription factors are involved in different processes (cell cycle regulation, cell death control, pre-mRNA processing and morphogenesis); one member of this family of proteins has been identified in the P. chrysogenum genome (Pc18g00430). In this work, we have characterized this novel transcription factor (named PcFKH1) by generating knock-down mutants and overexpression strains. Results clearly indicate that PcFKH1 positively controls antibiotic biosynthesis through the specific interaction with the promoter region of the penDE gene, thus regulating penDE mRNA levels. PcFKH1 also binds to the pcbC promoter, but with low affinity. In addition, it also controls other ancillary genes of the penicillin biosynthetic process, such as phlA (encoding phenylacetyl CoA ligase) and ppt (encoding phosphopantetheinyl transferase). PcFKH1 also plays a role in conidiation and spore pigmentation, but it does not seem to be involved in hyphal morphology or cell division in the improved laboratory reference strain Wisconsin 54-1255. A genome-wide analysis of processes putatively coregulated by PcFKH1 and PcRFX1 (another winged-helix transcription factor) in P. chrysogenum provided evidence of the global effect of these transcription factors in P. chrysogenum metabolism.