Technology for evaluating the ability of probiotic strains to accumulate copper ions in vitro and in vivo using Bacillus bacteria.

BACKGROUND AND AIM: Microorganisms of the genus Bacillus comprising probiotics could have an antitoxic effect that is manifested in the active excretion of toxic substances from the body, as well as heavy metals. This study was conducted to assess the effects of copper ions on probiotic strains based on the members of the genus Bacillus in vitro and in vivo. MATERIALS AND METHODS: The following probiotic preparations were selected for this experiment: "Sporobacterin," "Bactisubtil," and "Vetom-2." Sporobacterin liquid, manufactured by Bakoren LLC, is based on Bacillus subtilis 534. Bactisubtil, manufactured by Marion Merrell Dow, Inc., is based on Bacillus cereus 5832. The first part of the experiment (in vitro) was conducted to assess the influence of copper ions on the growth and bioaccumulating ability of probiotic strains. The second part of the experiment (in vivo) was conducted to assess the influence of copper ions on the body of laboratory animals and to determine the ability of probiotic strains to remove copper ions from the body of laboratory animals. Statistical analysis was performed using Statistical Package for the Social Sciences, calculating the average value (M), standard deviation (s), and standard deviation error (m). p<0.05 was used to denote statistical significance. RESULTS: In the previous studies, we found the presence of pronounced sorption characteristics of representatives of both the intestinal microbiome and probiotic strains based on them. In this study, we have studied the prospects of using physiological and adaptive mechanisms of resistance of transient probiotic strains in the system of correction of the elemental status of the animal body due to excessive intake of copper ions into the body. The advantage of their use is due to not only sorption but also the high levels of elimination of complexes accumulated on the surface. Analyzing the data, we can state the following. The excessive content of copper ions inhibits the activity of all microorganisms, and the presence of CuSO4 in the nutrient medium reduces the exponential growth phase by 6 h for B. licheniformis. The analysis of data on the bioaccumulating property of the probiotic strains under study shows that B. cereus (part of Bactisubtil) had the most pronounced sorbing effect with the level of accumulation of 23.96%. CONCLUSION: We found that probiotic preparations do not affect biochemical indices of blood and biotissues (the muscle and bone tissue, and the cutaneous covering). As a result of determining the ability of Bacillus bacteria comprising the probiotics under this study to accumulate heavy metals by measuring their concentration in the tissues of laboratory animals, the preparations contribute to reducing the toxic effects of copper ions on the body. The cutaneous covering has the greatest accumulation property relative to copper ions. The most effective probiotic under this study in copper ion poisoning was Bactisubtil, and the least effective was Vetom-2.

Perception of straightness and parallelism with minimal distance information.

The ability of human observers to judge the straightness and parallelism of extended lines has been a neglected topic of study since von Helmholtz's initial observations 150 years ago. He showed that there were significant misperceptions of the straightness of extended lines seen in the peripheral visual field. The present study focused on the perception of extended lines (spanning 90° visual angle) that were directly fixated in the visual environment of a planetarium where there was only minimal information about the distance to the lines. Observers were asked to vary the curvature of 1 or more lines until they appeared to be straight and/or parallel, ignoring any perceived curvature in depth. When the horizon between the ground and the sky was visible, the results showed that observers' judgements of the straightness of a single line were significantly biased away from the veridical, great circle locations, and towards equal elevation settings. Similar biases can be seen in the jet trails of aircraft flying across the sky and in Rogers and Anstis's new moon illusion (Perception, 42(Abstract supplement) 18, 2013, 2016). The biasing effect of the horizon was much smaller when observers were asked to judge the straightness and parallelism of 2 or more extended lines. We interpret the results as showing that, in the absence of adequate distance information, observers tend to perceive the projected lines as lying on an approximately equidistant, hemispherical surface and that their judgements of straightness and parallelism are based on the perceived separation of the lines superimposed on that surface.

The new moon illusion and the role of perspective in the perception of straight and parallel lines.

In the new moon illusion, the sun does not appear to be in a direction perpendicular to the boundary between the lit and dark sides of the moon, and aircraft jet trails appear to follow curved paths across the sky. In both cases, lines that are physically straight and parallel to the horizon appear to be curved. These observations prompted us to investigate the neglected question of how we are able to judge the straightness and parallelism of extended lines. To do this, we asked observers to judge the 2-D alignment of three artificial "stars" projected onto the dome of the Saint Petersburg Planetarium that varied in both their elevation and their separation in horizontal azimuth. The results showed that observers make substantial, systematic errors, biasing their judgments away from the veridical great-circle locations and toward equal-elevation settings. These findings further demonstrate that whenever information about the distance of extended lines or isolated points is insufficient, observers tend to assume equidistance, and as a consequence, their straightness judgments are biased toward the angular separation of straight and parallel lines.

The absorption spectrum of water near 750 nm by CW-CRDS: contribution to the search of water dimer absorption.

The absorption spectrum of natural water vapour around 750 nm has been recorded with a typical sensitivity of 3 x 10(-10) cm(-1) using a cw cavity ring down spectroscopy set up based on a Ti:sapphire laser. The 13 312.4-13 377.7 cm(-1) spectral interval was chosen as it corresponds to the region where water dimer absorption was recently measured (K. Pfeisticker et al., Science, 2003, 300, 2078-2080). The line parameters (wavenumber and intensity) of a total of 286 lines of water vapor were measured by a one by one fit of the lines to a Voigt profile. For the main water isotopologue, 276 lines were measured with line intensities as weak as 5 x 10(-29) cm molecule(-1)i.e. about 50 times smaller than the weakest H(2)16O line intensities included in the 2004 edition of the HITRAN database. On the basis of the predictions of Schwenke and Partridge, all but 16 lines could be assigned to different isotopologues of water (H(2)16O, H(2)18O, and HD16O) present in natural abundance in the sample. A total of 272 energy levels of H(2)16O were determined and rovibrationally assigned to 18 upper vibrational states. Half of them had not been reported previously. The importance of the additional absorbance resulting from the observation of many new weak lines is discussed in relation to the detection of water dimer absorption and compared to the absorbance predicted by Schwenke and Partridge. The quality of the line parameters of water monomer is shown to be of crucial importance to identify the absorbance of the water dimer in the considered region.