Application of novel starter cultures for sourdough bread production

Sourdough application has been extensively increased in the last years due to the consumers demand for food consumption without the addition of chemical preservatives. Several starter cultures have been applied in sourdough bread making targeting the increase of bread self-life and the improvement of sensorial character. More specific, Lactobacillus acidophilus and Lactobacillus sakei as single and mixed cultures were used for sourdough bread making. Various sourdough breads were produced with the addition of sourdough perviously prepared with 10% w/w L. acidophilus, 10% w/w L. sakei and 5% w/w L. acidophilus and 5% w/w L. sakei at the same time. Various chemical parameters were determined such as lactic acid, total titratable acidity and pH. The results revealed that the produced sourdough bread made with sourdough containing the mixed culture was preserved for more days (12 days) than all the other breads produced in the frame of this study, since it contained lactic acid in higher concentrations. The respective total titratable acidity varied between 10.5 and 11 ml NaOH N/10. The same sourdough bread had a firmer texture, better aroma, flavor and overall quality compared to other sourdough breads examined in this study, as shown by sensory evaluation tests and results obtained through SPME GC–MS analysis, which revealed significant differences among the different bread types.     

Hygienic quality and antibiotic resistance profile of sliced butchery

In order to investigate the microbiological quality of different meat products on the Greek market, 200 samples were collected from the following preparations: boiled turkey (n = 50), boiled pork ham (n = 50), smoked turkey (n = 50) and smoked pork ham (n = 50).In all cold meat preparations Clostridium perfringens vegetative and spore forms, Staphylococcus aureus, Escherichia coli and other Clostridium sp lec(-), as well as Lactobacillus, Bacillus sp. and Salmonella sp. were recovered. For instance Bacillus cereus was present in 6% of the samples.L. monocytogenes, Campylobacter jejuni and Campylobacter coli were rarely present (1–4%) while Yersinia enterocolitica and Campylobacter lari were absent. Differences in the occurrence of S. aureus, Salmonella sp., E. coli and spore forms of C. perfringens in boiled and smoked samples, reflects either the differences in the processing of the foods or could be associated to the extensive handling by the personnel during the purchasing (storage, slicing, wrapping).Antibiotic resistance on specific antibiotics for each pathogen was also studied. A multiresistance antibiotic profile was effective for most bacterial strains, and pronounced resistance profiles were observed for the commonly used antibiotics as ampicillin, penicillin, cephalothin, streptomycin followed by ceftriaxone and gentamycin. Albeit this high observed resistance profile, the tested strains generally conserved their susceptibility to amikacin, aztreonam, chloramphenicol and tylosin conserved an almost absent resistance. Antibiotics commonly used for therapeutic purposes, as well as antibiotics added to feed stuff of animals for increasing animal flesh production should contribute to the extensive spreading of antibiotic resistance in food and the environment.Systematically monitoring of the microbiological quality of cold butchery preparations must be done, in order to preserve food quality, optimizing the processing and elaboration methods of the product and safeguard the public health.     

Physical, chemical and microbiological quality of ice used to cool drinks and foods in Greece and its public health implications

Ice used for direct human consumption or to preserve foods and cool down drinks can be contaminated with pathogenic microorganisms and may potentially become a vehicle for consumer’s infection. To evaluate physical, chemical and microbiological quality of commercial ice and ice used for fish and seafood, 100 ice samples collected at 10 different retail points in the region of Epirus were studied. The following microbiological parameters were determined: Total coliforms, fecal coliforms, Salmonella spp., Shigella spp., Yersinia spp., Escherichia coli, Campylobacter sp., Vibrio cholerae, Aeromonas spp., Pseudomonas aeruginosa and Clostridium perfringens.E. coli was detected in 22% and coliforms were detected in 31% of samples. Samples in which coliforms were detected fail to meet the microbiological criteria specified by the drinking water legislation.Aeromonas spp., Shigella spp., Campylobacter sp. and V. cholerae were not detected. Spore forms of C. perfringens were prevalent at 35% and the psychotropic bacterium’s P. aeruginosa and Yersinia spp. were found only at three samples each.The presence of large numbers of coliforms as well as of other pathogenic strains suggested that commercial ice and ice used to make cool drinks or in preservation of fish and seafood may represent a potential hazard to the consumer. In view of the results reported herein, it is highly recommended that national regulatory guidelines should be established for the production of ice as long as regular inspections.     

Anaerobicizing into pluripotency

Reprogramming involves multiple layers of molecular regulation, yet it remains relatively unknown how the cell's metabolism is changing and/or contributing to this process. In this issue of Cell Metabolism, Folmes et?al. (2011) demonstrate that reprogramming induces a bioenergetic transition from an oxidative to a glycolytic state, and provide evidence to suggest that these changes may precede pluripotency.     

iPSCs: induced back to controversy

Several recent reports (Mayshar et?al., 2010; Laurent et?al., 2011; Lister et?al., 2011; Gore et?al., 2011; Hussein et?al., 2011) uncover genetic and epigenetic alterations in induced pluripotent stem cells, stimulating debate about their future. However, will these important findings really impact what we hope to gain?     

Linking Pre-Diabetes with Benign Prostate Hyperplasia. IGFBP-3: A Conductor of Benign Prostate Hyperplasia Development Orchestra?

Benign prostatic hyperplasia (BPH) represents a pattern of non-malignant growth of prostatic fibromuscular stroma. Metabolic disturbances such us pre-diabetes and metabolic syndrome may have a role in BPH pathophysiology. A potential explanation for the above relationship involves the insulin-like growth factor (IGF) axis as well as IGF binding proteins, (IGFBPs) of which the most abundant form is IGFBP-3. Therefore, the aim of the present study was to investigate the association between intra-prostatic levels of IGF-1, IGF-2 as well as to evaluate the role of locally expressed IGFBP-3 in BPH development in pre-diabetes. A total of 49 patients admitted to the Urology department of a tertiary urban Greek hospital, for transurethral prostate resection, or prostatectomy and with pre-diabetes [impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) or both] were finally included. The majority of the sample consisted of subjects with IGT (51.0%), followed by IFG and IGT (32.7%) and isolated IFG (16.3%). For all participants a clinical examination was performed and blood samples were collected. In addition, total prostate (TP) volume or transitional zone (TZ) volume were estimated by transrectal ultrasonography. The results of the multivariate analysis regarding TP volume showed that higher PSA (p<0.001), larger waist circumference (p=0.007) and higher IGFBP-3 expression levels (p<0.001) independently predicted higher TP volume. The results regarding the volume of the TZ showed that higher PSA (p<0.001), larger waist circumference (p<0.001) and higher IGFBP-3 expression levels (p=0.024) were independently associated with higher TZ volume. Our findings show that intra-prostatic levels of IGFBP-3, PSA and waist circumference, but not overall obesity, are positively associated with prostate volume. IGFBP-3 seems to be a multifunctional protein, which can potentiate or inhibit IGF activity.     

Lowering of interstitial fluid pressure after neurogenic inflammation in mouse skin is partly dependent on mast cells

Neurogenic inflammation is known to induce lowering of interstitial fluid pressure (P(if)) in mouse skin. This study examined the possible role of mast cell activation secondary to neuropeptide release in lowering of P(if) by using Kit(W)/Kit(W-v) mice, which are devoid of mast cells, including connective tissue mast cells (CTMCs). P(if) was measured in paw skin of anesthetized (fentanyl-fluanison and midazolam, 1:1) mice with glass capillaries connected to a servo-controlled counterpressure system. In contrast to wild-type mice, intravenous administration of mast cell-activating compound 48/80 induced no lowering of P(if) in Kit(W)/Kit(W-v) mice. Intravenous challenge with substance P (SP), calcitonin gene-related peptide (CGRP), or capsaicin induced a significant (P < 0.05) lowering of P(if) in wild-type mice to -2.16 +/- 0.28, -1.96 +/- 0.11, and -2.22 +/- 0.19 mmHg, respectively, compared with vehicle (-0.49 +/- 0.11 mmHg). In Kit(W)/Kit(W-v) mice the P(if) response to SP was completely abolished (-0.53 +/- 0.32 mmHg) while the response to CGRP and capsaicin was attenuated (-1.33 +/- 0.13 and -1.42 +/- 0.13 mmHg, respectively) although significantly (P < 0.05) lowered compared with vehicle. Immunohistochemical analysis revealed no difference in distribution or density of SP- and CGRP-immunoreactive fibers in paws of Kit(W)/Kit(W-v) compared with wild-type mice. We conclude that lowering of P(if) normally depends on mast cells. However, the sensory nerves can also elicit a lowering of P(if) that is independent of mast cells.     

Plant cytosine-5 DNA methyltransferases: structure, function, and molecular evolution

A detailed analysis of the structure and function, along with evolutionary aspects, of the main plant cytosine-5 DNA methyltransferases (C5-MTases) is presented. The evolutionary relationships between the already known and four candidate plant C5-MTases identified in this work were investigated using the distance, maximum-parsimony, and maximum-likelihood approaches. The topologies of the trees were overall congruent: four monophyletic groups corresponding to the four plant C5-MTase families were clearly distinguished. In addition, sequence analyses of the plant C5-MTase target recognition domain sequences were performed and phylogenetic trees were reconstructed showing that there is good conservation among but not within the plant C5-MTase families. Furthermore, a conserved dipeptide that plays an important role in flipping the target base into the catalytic site of the C5-MTases was identified in all plant C5-MTases under study.     

Flow-Regulated Endothelial S1P Receptor-1 Signaling Sustains Vascular Development

During angiogenesis, nascent vascular sprouts fuse to form vascular networks, enabling efficient circulation. Mechanisms that stabilize the vascular plexus are not well understood. Sphingosine 1-phosphate (S1P) is a blood-borne lipid mediator implicated in the regulation of vascular and immune systems. Here we describe a mechanism by which the G protein-coupled S1P receptor-1 (S1P(1)) stabilizes the primary vascular network. A gradient of S1P(1) expression from the mature regions of the vascular network to the growing vascular front was observed. In the absence of endothelial S1P(1), adherens junctions are destabilized, barrier function is breached, and flow is perturbed, resulting in abnormal vascular hypersprouting. Interestingly, S1P(1) responds to S1P?as well as laminar shear stress to transduce flow-mediated signaling in endothelial cells both in?vitro and in?vivo. These data demonstrate that blood flow and circulating S1P activate endothelial S1P(1) to stabilize blood vessels in development and homeostasis.