0000000000303554
AUTHOR
Laisana Shakirova
Hydrophobicity of bacteria Zymomonas mobilis under varied environmental conditions
Abstract Changes in the cell surface hydrophobicity (CSH) of bacteria Zymomonas mobilis 113S were examined in response to varied environmental conditions (temperature and phase of growth, concentration or type of carbon source, the presence of amphiphilic compounds). The values of CSH were elevated with a decreased growth rate over the time of cultivation up to 20–22% at the stationary phase. CSH values increased proportionally with the growth of cultivation temperature and concentration of carbon source (glucose or sucrose) or amphiphilic compound (aliphatic alcohols, Tween80) in the medium. Replacement of sucrose by glucose and the presence of Tween20 in the growth medium resulted in redu…
FT-IR spectroscopic investigation of bacterial cell envelopes from Zymomonas mobilis which have different surface hydrophobicities
Abstract Changes in the cell envelope composition of bacteria Zymomonas mobilis 113S which resulted in varied cell surface hydrophobicity (CSH) were examined using FT-IR-spectroscopy and conventional methods of biochemical analysis. Significant differences in all analyses were detected between hydrophilic and hydrophobic compounds in the envelopes of Z. mobilis . A significant positive linear relationship ( P Z. mobilis and the ratio of absorbance band intensities assigned to the CH 2 and CH 3 vibrations from lipids as well as the asymmetric and symmetric stretching vibrations of these methylene and methyl groups. Differences were also seen between the ratio of band absorbances arising from…
Production of extracellular fructans by Gluconobacter nephelii P1464.
UNLABELLED Bacterial extracellular fructans, known as levans, have potential applications in food, pharmaceutical and cosmetic industries and high fructan producing strains could contribute into the cost reduction and more extensive commercial usage of them. An acetic acid bacteria (AAB) isolate P1464 was obtained from the Microbial Strain Collection of Institute of Microbiology and Biotechnology, University of Latvia and identified as Gluconobacter nephelii by DNA-DNA hybridization and the formation of extracellular fructans by this strain was confirmed. Isolated extracellular fructose polymers were characterized using FT-IR spectroscopy and the structural features of fructan appeared as s…
The effect of amphiphilic compounds on the secretion of levansucrase by Zymomonas mobilis
Abstract The effect of some aliphatic (n-butanol to n-hexadecanol) and aromatic (benzyl and phenethyl alcohols), anesthetics (procaine) and surfactants (Tween 20 to Tween 80) on the secretion of levansucrase by the levan-producing strain of Gram-negative ethanologenic bacteria Zymomonas mobilis 113S were examined in this study. During incubation of Z. mobilis cells with sucrose (10 mM) a decrease of the levansucrase activity was observed in the presence of these amphiphilic compounds concomitantly with an increase of a total amount of protein in the medium. Since none of the compounds under study had any effect on enzyme activity in vitro observed structure- and concentration-dependent rela…
Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 cell surface hydrophobicity and survival of the cells under adverse environmental conditions.
Abstract Changes in the cell surface hydrophobicity (CSH) of probiotic bacteria Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 and the survival of these cells were examined in response to varied cultivation conditions and adverse environmental conditions. An inverse linear relationship (P < 0.01) was detected between the CSH of intact L. acidophilus La5 and B. lactis Bb12 and survival of cells subjected to subsequent freezing/thawing, long-term storage or exposure to mineral and bile acids. The observed relationships were supported by significant correlations between the CSH and changes in composition of the cell envelopes (proteins, lipids and carbohydrates) of L. aci…