Characterization and Genome Study of Novel Lytic Bacteriophages against Prevailing Saprophytic Bacterial Microflora of Minimally Processed Plant-Based Food Products

The food industry is still searching for novel solutions to effectively ensure the microbiological safety of food, especially fresh and minimally processed food products. Nowadays, the use of bacteriophages as potential biological control agents in microbiological food safety and preservation is a promising strategy. The aim of the study was the isolation and comprehensive characterization of novel bacteriophages with lytic activity against saprophytic bacterial microflora of minimally processed plant-based food products, such as mixed leaf salads. From 43 phages isolated from municipal sewage, four phages, namely Enterobacter phage KKP 3263, Citrobacter phage KKP 3664, Enterobacter phage KKP 3262, and Serratia phage KKP 3264 have lytic activity against Enterobacter ludwigii KKP 3083, Citrobacter freundii KKP 3655, Enterobacter cloacae KKP 3082, and Serratia fonticola KKP 3084 bacterial strains, respectively. Transmission electron microscopy (TEM) and whole-genome sequencing (WGS) identified Enterobacter phage KKP 3263 as an Autographiviridae, and Citrobacter phage KKP 3664, Enterobacter phage KKP 3262, and Serratia phage KKP 3264 as members of the Myoviridae family. Genome sequencing revealed that these phages have linear double-stranded DNA (dsDNA) with sizes of 39,418 bp (KKP 3263), 61,608 bp (KKP 3664), 84,075 bp (KKP 3262), and 148,182 bp (KKP 3264). No antibiotic resistance genes, virulence factors, integrase, recombinase, or repressors, which are the main markers of lysogenic viruses, were annotated in phage genomes. Serratia phage KKP 3264 showed the greatest growth inhibition of Serratia fonticola KKP 3084 strain. The use of MOI 1.0 caused an almost 5-fold decrease in the value of the specific growth rate coefficient. The phages retained their lytic activity in a wide range of temperatures (from −20 °C to 50 °C) and active acidity values (pH from 4 to 11). All phages retained at least 70% of lytic activity at 60 °C. At 80 °C, no lytic activity against tested bacterial strains was observed. Serratia phage KKP 3264 was the most resistant to chemical factors, by maintaining high lytic activity across a broader range of pH from 3 to 11. The results indicated that these phages could be a potential biological control agent against saprophytic bacterial microflora of minimally processed plant-based food products.     

Maximum oil film pressure and temperature of two‐iobe journal bearings with different bush profiles

This paper presents data on the maximum oil film pressure and temperature of two‐lobe journal bearings with different bore profiles. A bearing with a cylindrical non‐continuous bore profile, and another with a pericycloid continuous profile have been evaluated. For an assumed relative length of the bearings, and parallel orientation of the journal and bearing axes, the minimum values of oil film thickness, maximum pressure values, and temperatures of the oil film have been determined. The calculations were carried out on the assumption of an adiabatic oil film and a static equilibrium position of the journal.     

Isomerization of 4-Bromo-2-methyl-5-nitro-1-phenacylimidazoles into 5-Bromo-2-methyl-4-nitro-1-phenacylimidazoles

4-Bromo-2-methyl-5-nitro-1-phenacylimidazoles ( 1a-e ) dissolved in EtOH in presence of sodium bicarbonate (or without it) heated under reflux were isomerized into 5-bromo-2-methyl-4-nitro-1-phenacylimidazoles ( 5a-e ). The structures of 5a-e were assigned using SFORD (Single Frequency Off Resonance Decoupling) and COLOC (Correlation Spectroscopy for Long Range Coupling) NMR techniques. A conceivable mechanism of isomerization is discussed.     

β-Casomorphin-7 isolated from Brie cheese

Peptide extract from Brie cheese was examined. The opioid peptide was isolated from the extract. Its amino acid composition and N- and C-terminal amino acids were determined. Based on these analyses, the isolated peptide was assumed to correspond to β-casomorphin-7 (Tyr-Pro-Phe-Pro-Gly-Pro-IIe). The opioid activity was measured by examining the effects of peptide extract and isolated opioid peptide on the motor activity of isolated rabbit intestine. © 1999 Society of Chemical Industry     

Potential of Trichoderma harzianum and Its Metabolites to Protect Wheat Seedlings against Fusarium culmorum and 2,4-D

Wheat is a critically important crop. The application of fungi, such as Trichoderma harzianum, to protect and improve crop yields could become an alternative solution to synthetic chemicals. However, the interaction between the fungus and wheat in the presence of stress factors at the molecular level has not been fully elucidated. In the present work, we exposed germinating seeds of wheat (Triticum aestivum) to the plant pathogen Fusarium culmorum and the popular herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in the presence of T. harzianum or its extracellular metabolites. Then, the harvested roots and shoots were analyzed using spectrometry, 2D-PAGE, and MALDI-TOF/MS techniques. Although F. culmorum and 2,4-D were found to disturb seed germination and the chlorophyll content, T. harzianum partly alleviated these negative effects and reduced the synthesis of zearalenone by F. culmorum. Moreover, T. harzianum decreased the activity of oxidoreduction enzymes (CAT and SOD) and the contents of the oxylipins 9-Hode, 13-Hode, and 13-Hotre induced by stress factors. Under the influence of various growth conditions, changes were observed in over 40 proteins from the wheat roots. Higher volumes of proteins and enzymes performing oxidoreductive functions, such as catalase, ascorbate peroxidase, cytochrome C peroxidase, and Cu/Zn superoxide dismutase, were found in the Fusarium-inoculated and 2,4-D-treated wheat roots. Additionally, observation of the level of 12-oxo-phytodienoic acid reductase involved in the oxylipin signaling pathway in wheat showed an increase. Trichoderma and its metabolites present in the system leveled out the mentioned proteins to the control volumes. Among the 30 proteins examined in the shoots, the expression of the proteins involved in photosynthesis and oxidative stress response was found to be induced in the presence of the herbicide and the pathogen. In summary, these proteomic and metabolomic studies confirmed that the presence of T. harzianum results in the alleviation of oxidative stress in wheat induced by 2,4-D or F. culmorum.     

Calmodulin as Ca2+-Dependent Interactor of FTO Dioxygenase

FTO is an N⁶-methyladenosine demethylase removing methyl groups from nucleic acids. Several studies indicate the creation of FTO complexes with other proteins. Here, we looked for regulatory proteins recognizing parts of the FTO dioxygenase region. In the Calmodulin (CaM) Target Database, we found the FTO C-domain potentially binding CaM, and we proved this finding experimentally. The interaction was Ca²⁺-dependent but independent on FTO phosphorylation. We found that FTO–CaM interaction essentially influences calcium-binding loops in CaM, indicating the presence of two peptide populations—exchanging as CaM alone and differently, suggesting that only one part of CaM interacts with FTO, and the other one reminds free. The modeling of FTO–CaM interaction showed its stable structure when the half of the CaM molecule saturated with Ca²⁺ interacts with the FTO C-domain, whereas the other part is disconnected. The presented data indicate calmodulin as a new FTO interactor and support engagement of the FTO protein in calcium signaling pathways.     

Some aspects of isotactic polypropylene crystallization in an ethylene–propylene–diene rubber matrix

Crystallization of isotactic polypropylene (iPP) in an ethylene–propylene–diene rubber matrix (EPDM), crosslinked with dicumyl peroxide (DCP), has been studied. A discrepancy concerning the degree of crystallinity of the blends determined using different experimental techniques, has been discovered and an effort to explain it is made. iPP was found to recrystallize in EPDM in a manner, depending on the amount of plastomer added. Nucleation, being predominantly homogeneous for ‘pure’ iPP, becomes predominantly hetero-geneous for its blends with EPDM. The smaller the polypropylene content the more a defect crystalline phase is formed. The defects, as well as an orientation were shown to be responsible for the higher, in comparison with other methods, degree of crystallinity determined by wide-angle X-ray scattering. ©1997 SCI     

Acute Effect of Caffeine on the Synthesis of Pro-Inflammatory Cytokines in the Hypothalamus and Choroid Plexus during Endotoxin-Induced Inflammation in a Female Sheep Model

This study was designed to determine the effect of acute caffeine (CAF) administration, which exerts a broad spectrum of anti-inflammatory activity, on the synthesis of pro-inflammatory cytokines and their receptors in the hypothalamus and choroid plexus (ChP) during acute inflammation caused by the injection of bacterial endotoxin—lipopolysaccharide (LPS). The experiment was performed on 24 female sheep randomly divided into four groups: control; LPS treated (iv.; 400 ng/kg of body mass (bm.)); CAF treated (iv.; 30 mg/kg of bm.); and LPS and CAF treated. The animals were euthanized 3 h after the treatment. It was found that acute administration of CAF suppressed the synthesis of interleukin (IL-1β) and tumor necrosis factor (TNF)α, but did not influence IL-6, in the hypothalamus during LPS-induced inflammation. The injection of CAF reduced the LPS-induced expression of TNF mRNA in the ChP. CAF lowered the gene expression of IL-6 cytokine family signal transducer (IL6ST) and TNF receptor superfamily member 1A (TNFRSF1) in the hypothalamus and IL-1 type II receptor (IL1R2) in the ChP. Our study on the sheep model suggests that CAF may attenuate the inflammatory response at the hypothalamic level and partly influence the inflammatory signal generated by the ChP cells. This suggests the potential of CAF to suppress neuroinflammatory processes induced by peripheral immune/inflammatory challenges.