Expression of genes involved in metabolism of phenolic compounds by Lactobacillus pentosus and its relevance for table-olive fermentations

Genes with the potential to code for enzymes involved in phenolic compound metabolism were detected in the genome of Lactobacillus pentosus IG1, isolated from a green olive fermentation. Based on homology, these genes could code for a 6-P-β Glucosidase, two different Tannases, a Gallate decarboxylase and a p-Coumaric decarboxylase. Expression of up to seven of these genes was studied in L. pentosus IG1 (olive fermentation) and CECT4023^T (corn silage), including responses upon exposure to relevant phenolic compounds and different olive extracts. Genes potentially coding Tannase, Gallate decarboxylase and p-Coumaric acid decarboxylase significatively increased their expression upon exposure to such compounds and extracts, although it was strain dependent. In general, both the genetic organization and the characteristics of gene expression resembled very much those described for Lactobacillus plantarum. In accordance to the observed induced gene expression, metabolism of specific phenolic compounds was achieved by L. pentosus. Thus, methyl gallate, gallic acid and the hydroxycinamic acids p-coumaric, caffeic and ferulic were metabolized. In addition, the amount of phenolics such as tyrosol, oleuropein, rutin and verbascoside included in a minimal culture medium was noticeably reduced, again dependent on the strain considered.

A duality principle for the multi-block entanglement entropy of free fermion systems

The analysis of the entanglement entropy of a subsystem of a one-dimensional quantum system is a powerful tool for unravelling its critical nature. For instance, the scaling behaviour of the entanglement entropy determines the central charge of the associated Virasoro algebra. For a free fermion system, the entanglement entropy depends essentially on two sets, namely the set A of sites of the subsystem considered and the set K of excited momentum modes. In this work we make use of a general duality principle establishing the invariance of the entanglement entropy under exchange of the sets A and K to tackle complex problems by studying their dual counterparts. The duality principle is also a key ingredient in the formulation of a novel conjecture for the asymptotic behavior of the entanglement entropy of a free fermion system in the general case in which both sets A and K consist of an arbitrary number of blocks. We have verified that this conjecture reproduces the numerical results with excellent precision for all the configurations analyzed. We have also applied the conjecture to deduce several asymptotic formulas for the mutual and r-partite information generalizing the known ones for the single block case.

Patented techniques for acrylamide mitigation in high-temperature processed foods

Heating foods has many advantages since it adds taste, color, texture and minimizes harmful germs, among others. Flavor and aroma compounds are produced via the Maillard reaction, where various hazardous compounds may form as well, such as acrylamide. Maillard reaction is believed to be the main route for acrylamide formation between reducing sugars (glucose and fructose), sucrose, and the amino acid asparagine, and, consequently, a variety of technologies have been developed to reduce acrylamide concentration in thermally processed foods based either on: (i) Changing process parameters (e.g. time and temperature of cooking) which inhibits Maillard Reaction; (ii) Reducing acrylamide precursor levels in raw materials to be cooked at high temperatures (e.g. by using microorganisms, asparaginase, amino acids and saccharides, blanching, etc.). In this paper, most of the recent patents for acrylamide reduction in foods processed at high temperatures are mentioned and briefly analyzed in order to develop new mitigation techniques for acrylamide in different food matrixes.

Fast optical source for quantum key distribution based on semiconductor optical amplifiers

A novel integrated optical source capable of emitting faint pulses with different polarization states and with different intensity levels at 100 MHz has been developed. The source relies on a single laser diode followed by four semiconductor optical amplifiers and thin film polarizers, connected through a fiber network. The use of a single laser ensures high level of indistinguishability in time and spectrum of the pulses for the four different polarizations and three different levels of intensity. The applicability of the source is demonstrated in the lab through a free space quantum key distribution experiment which makes use of the decoy state BB84 protocol. We achieved a lower bound secure key rate of the order of 3.64 Mbps and a quantum bit error ratio as low as 1.14×10⁻² while the lower bound secure key rate became 187 bps for an equivalent attenuation of 35 dB. To our knowledge, this is the fastest polarization encoded QKD system which has been reported so far. The performance, reduced size, low power consumption and the fact that the components used can be space qualified make the source particularly suitable for secure satellite communication.

Ochrobactrum cytisi sp. nov., isolated from nodules of Cytisus scoparius in Spain

Two strains named ESC1(T) and ESC5 were isolated from nodules of Cytisus scoparius growing in a Spanish soil. Phylogenetic analysis of the 16S rRNA gene showed that these strains belong to the genus Ochrobactrum, their closest relatives being Ochrobactrum anthropi and Ochrobactrum lupini, with 100 and 99.9 % similarity to the respective type strains. Despite this high similarity, the results of DNA-DNA hybridization, phenotypic tests and fatty acid analyses showed that these strains represent a novel species of genus Ochrobactrum. The DNA-DNA hybridization values were respectively 70, 66 and 55 % with respect to O. lupini LUP21(T), O. anthropi DSM 6882(T) and Ochrobactrum tritici DSM 13340(T). The predominant fatty acids were C(18 : 1)omega7c and C(18 : 1) 2-OH. Strains ESC1(T) and ESC5 were strictly aerobic and were able to reduce nitrate and to hydrolyse aesculin. They produced beta-galactosidase and beta-glucosidase and did not produce urease after 48 h incubation. The G+C content of strain ESC1(T) was 56.4 mol%. Both strains ESC1(T) and ESC5 contained nodD and nifH genes on megaplasmids that were related phylogenetically to those of rhizobial strains nodulating Phaseolus, Leucaena, Trifolium and Lupinus. From the results of this work, we propose that the strains isolated in this study be included in a novel species named Ochrobactrum cytisi sp. nov. The type strain is ESC1(T) (=LMG 22713(T)=CECT 7172(T)).

New screening method for lung cancer by detecting volatile organic compounds in breath

Lung cancer is a frequent cause of cancer-related deaths in the world. There is no valid screening process and this limits its detection to the late stages, with consequently high mortality rates. Volatile organic compounds (VOC) are chemical compounds (mainly the products of cell catabolism) found as gases in the human breath. Different methods have been developed to analyse VOCs and to compare them in healthy subjects and lung cancer patients. In this review, we summarise the different techniques used to analyse VOC. Many reports have been published with promising results similar to those achieved with accepted screening methods such as mammography. These methods show good perspectives on lung cancer screening.

Evaluation of the metal phytoextraction potential of crop legumes. Regulation of the expression of O-acetylserine (thiol)lyase under metal stress

The metal phytoextraction potential of three legumes belonging to different genera has been studied under greenhouse conditions. Legumes accumulate As and metals mainly in roots, although translocation to shoot is observed. Alfalfa did accumulate the highest concentrations of As and metals in shoots and aerial biomass was less affected by the toxic elements, indicating its good behaviour in phytoextraction. Clover accumulated less metal, but showed larger biomass. EDTA addition enhanced Pb phytoextraction up to levels similar to those described for plants proposed in phytoremediation. The regulation of O-acetylserine (thiol)lyase from legumes under metal stress has been analysed to test the possibility of establishing a possible correlation between the expression of OASTL in the presence of the metals and the metal accumulation in legume plant tissues. Cd and Pb(EDTA) produce the strongest increases of OASTL activity, with the higher enhancement seen in roots, in parallel with the higher metal accumulation. Arsenic produced an increase of root enzyme activity, whereas Cu produced a decrease, mainly in shoots. Western blots using antibodies against an A. THALIANA cytosolic OAS-TL recognised up to five protein bands in crude extracts from LOTUS and clover. A low molecular weight isoform of 32 kDa was induced in the presence of Cd and Pb. A partial RT-PCR sequence from clover has been obtained, showing 86 - 97 % identity with other described OASTLs. The PCR fragment has been used to analyse OASTL mRNA levels of legumes under metal stress. OASTL transcripts were increased by As, Cd, and Pb, especially in roots, where metal accumulation was maximal, while Cu produced a decrease in the transcript levels.

Different serum interleukin-12 and sCD30 levels in food- and pollen-sensitized children

It has been proposed that a down-regulation of interleukin (IL)-12 and interferon (IFN)-gamma might be related to susceptibility to allergy in early life. The aim of this study was to assess serum IL-12 levels in food-sensitized and pollen-sensitized children and to compare these with another activation marker, sCD30. Twenty children with pollen allergy and 22 food-sensitized children were included. The diagnosis of immunoglobulin (Ig)-E-mediated allergy, suggested by clinical symptoms, was based on skin-prick tests, serum IgE antibodies and total IgE levels. Samples from 24 non-allergic children were used as controls. IL-12 and sCD30 levels were measured by ELISA. It was found that pollen-sensitized patients had normal IL-12 and higher sCD30 levels than controls (114 vs. 63 U/ml, p = 0.028), but, surprisingly, food-sensitized infants showed normal sCD30 and increased serum IL-12 levels (323 vs. 118 pg/ml, p = 0.0001). No differences were found in patients suffering from asthma or allergic dermatitis. Levels of sCD30 and IL-12 determined in May showed a strong correlation with those obtained in November. Interleukin-12 and IgE levels had an inverse correlation (r = -0.494, p = 0.0001) whereas no correlation was found between sCD30 and IgE. Age had a strong negative influence on IL-12 levels in allergic (Z = 4.834, p < 0.0005) and in normal children (Z = 3.00, p < 0.002); by contrast, sCD30 levels were not significantly age-dependent. When IL-12 levels from the food-allergy group were compared with those from normal controls younger than 4 years of age, the difference remained significant (p = 0.001), ruling out an age-bias. The conclusions made in this study were that serum IL-12 and sCD30 showed different behaviors in children with food or pollen allergy. We found IL-12 and sCD30 levels in pollen-allergic patients that agree with the classical T-helper (Th) 1/Th2 paradigm of allergy. In contrast, serum IL-12 levels were increased in food-sensitized children, suggesting a different immunologic pathogenesis.

[Spontaneous drainage of a pancreatic abscess into the digestive tract]

Pancreatic abscess is a serious complication of acute pancreatitis and the best treatment is surgical drainage, even when morbidity and mortality are high. We present a patient with a pancreatic abscess after cholecystectomy and bile duct drainage because of cholelithiasis and pancreatitis. The abscess was manifested by a palpable painful mass in the epigastrium, fever, leukocytosis, and confirmed by ultrasound. Through a nasogastric tube we drained necrotic and purulent material with gradual and complete recovery. This is the first case in our hospital in which a pancreatic abscess drained spontaneously into the digestive tract without requiring external drainage.