Antibacterial Activity of a Novel Oligosaccharide from Streptomyces californics against Erwinia carotovora subsp. Carotovora

The present study aims to characterize and predict models for antibacterial activity of a novel oligosaccharide from Streptomyces californics against Erwinia carotovora subsp. carotovora using an adaptive neuro-fuzzy inference system and an artificial neural network. The mathematical predication models were used to determine the optimal conditions to produce oligosaccharide and determine the relationship between the factors (pH, temperature, and time). The characteristics of the purified antibacterial agent were determined using ultraviolet spectroscopy (UV/Vis), infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (¹H- and ¹³C-NMR), and mass spectrometry (MS). The best performances for the model were 39.45 and 35.16 recorded at epoch 1 for E. carotovora Erw₅ and E. carotovora EMCC 1687, respectively. The coefficient (R²) of the training was more than 0.90. The highest antimicrobial production was recorded after 9 days at 25 °C and a pH of 6.2, at which more than 17 mm of the inhibition zone was obtained. The mass spectrum of antimicrobial agent (peak at R.T. = 3.433 of fraction 6) recorded two molecular ion peaks at m/z = 703.70 and m/z = 338.30, corresponding to molecular weights of 703.70 and 338.30 g/mol, respectively. The two molecular ion peaks matched well with the molecular formulas C₂₉H₅₃NO₁₈ and C₁₄H₂₆O₉, respectively, which were obtained from the elemental analysis result. A novel oligosaccharide from Streptomyces californics with potential activity against E. carotovora EMCC 1687 and E. carotovora Erw₅ was successfully isolated, purified, and characterized.     

Promoting Effect of Soluble Polysaccharides Extracted from Ulva spp. on Zea mays L. Growth

Seaweeds can play a vital role in plant growth promotion. Two concentrations (5 and 10 mg/mL) of soluble polysaccharides extracted from the green macroalgae Ulva fasciata and Ulva lactuca were tested on Zea mays L. The carbohydrate and protein contents, and antioxidant activities (phenols, ascorbic, peroxidase, and catalase) were measured, as well as the protein banding patterns. The soluble polysaccharides at 5 mg/mL had the greatest effect on the base of all of the parameters. The highest effects of soluble polysaccharides on the Zea mays were 38.453, 96.76, 4, 835, 1.658, 7.462, and 38615.19, mg/mL for carbohydrates, proteins, phenol, µg ascorbic/mL, mg peroxidase/g dry tissue, and units/g tissue of catalase, respectively. The total number of protein bands (as determined by SDS PAGE) was not changed, but the density of the bands was correlated to the treatments. The highest band density and promoting effect were correlated to 5 mg/mL soluble polysaccharide treatments extracted from Ulva fasciata in Zea mays, which can be used as a biofertilizer.     

Apis mellifera syriaca Venom: Evaluation of Its Anticoagulant Effect,Proteolytic Activity,and Cytotoxicity along with Its Two Main Compounds—MEL and PLA2—On HeLa Cancer Cells

Bee venom (BV) is one of the most remarkable natural products that has been a subject of studies since ancient times. Recent studies have shown that Apis mellifera syriaca venom possesses antibacterial as well as cytotoxic effects on cancer cell lines. The venom contains a variety of bioactive molecules—mainly melittin (MEL) and phospholipase A2 (PLA2), as well as other compounds that are not well characterized. In this work, we continue the biological characterization of A. mellifera syriaca venom by testing its anticoagulant effect on human plasma using the prothrombin time (PT) test, as well as assessing its proteolytic activity. In addition, the cytotoxicity of the crude venom—and of its two main components, MEL and PLA2—was tested on HeLa cancer cell lines for the first time. The results obtained showed the capacity of A. mellifera syriaca venom to increase clotting time, thereby proving its anticoagulant effect. Moreover, the venom did not demonstrate a significant proteolytic activity unless administrated at concentrations ≥ 5 mg/mL. Finally, we showed that crude A. mellifera syriaca venom, along with MEL, exhibit a strong in vitro cytotoxic effect on HeLa cancer cell lines, even at low concentrations. In summary, our findings could serve as a basis for the development of new natural-based drug candidates in the therapeutic field.     

Unique divisibility in Abelian groups

Acta Mathematica Hungarica -     

Off-axis-Gaussian beam intensity in random medium

The receiver intensity profile of an off-axis-Gaussian beam travelling in random medium is formulated. By examining the related exponential terms of this intensity expression, the rules governing the receiver plane displacements are deduced. Off-axis-Gaussian beam is characterized by introducing into a Gaussian beam, complex displacement parameters that exhibit transverse source coordinate dependent attenuation and phase shifts. Our results are applied to turbulent horizontal links. Intensity plots describing the dependence on the source and propagation parameters both on the source and the receiver planes are provided. Even though the normalized intensities of the off-axis-Gaussian beam having the same source sizes but differing displacements in x- and y-directions may look the same on the source plane, they will differentiate after propagation. The views from the progress of an off-axis-Gaussian beam along the turbulent link length show that a source displaced beam will act according to rules set by related exponential terms. An asymmetrical (ellipsoidal) off-axis-Gaussian beam will initially be converted into symmetric (circular) shape at the intermediate link lengths, then it will start to expand in the other direction, thus reverting to an ellipsoid shape whose major axis is now along the transverse coordinate opposite to that of the source plane.     

Temperature, H2 loading and ultra violet irradiation effects in germanosilicate optical fibers: laser spectroscopy measurements

The effects of heat-treatment and ultraviolet (UV) light at 325 nm on virgin and hydrogen loaded germanosilicate optical fibers have been investigated by using laser spectroscopy technique. The luminescence band around 650 nm is sensitive to heat treatment. The hydrogen reloading of the hydrogen loaded fibers subsequent to heat treatment showed a new emission band around 570 nm. The irradiated fibers have an emission band around 383 nm which was not detected in hydrogen loaded fibers.