Effects of Magnetic Field on Phenol Biodegradation and Cell Physiochemical Properties of Rhodococcus erythropolis

Using phenol-degrading Rhodococcus erythropolis cells, the stimulative effect of a homogenous electromagnetic field (EMF) (magnetic induction 10–130 mT) on the growth and utilization of phenol (0.3–1.2 g/L) was investigated. Similarly, the EMF effect was tested on a R. erythropolis biofilm formation, which was found to increase the cell adhesion abilities significantly. Detected magnetic stimulation of cell adhesion disposition was supplemented with the results of cell surface hydrophobicity and chemical composition analysis.     

An insight into the genetic polymorphism among European populations of Lactuca serriola assessed by AFLP

Prickly lettuce (Lactuca serriola) is world-wide distributed and very variable species generally considered as a progenitor of the cultivated lettuce (Lactuca sativa). Altogether, 50 populations of L. serriola were characterized by means of amplified fragment length polymorphism (AFLP) and by isozyme analysis. Relationships among individuals and populations were examined by applying the unweighted pair-group method with the arithmetic averages (UPGMA) clustering algorithm, principal coordinate analysis (PCA) and the Nei's gene diversity index. The studied set of populations split into three main groups based on the AFLP polymorphism analysis. The first group contained L. sativa (control). The second group comprised two L. serriola accessions; one of them was identified as L. serriola f. integrifolia and the other as a mixture of two L. serriola forms. The largest and the most diverse third group contained the remaining L. serriola accessions. The population clustering corresponded approximately to their geographical distribution in Europe. At least five distinct geographic groups were recognised: 1) Northern European; 2) Slovenian; 3) very heterogeneous Central and Western European (mostly north of the Alps); 4) Mediterranean; 5) prevalence of L. serriola f. integrifolia, mostly comprising accessions from the United Kingdom and the Netherlands. This study showed that accessions originating in various eco-geographical conditions of Europe differ significantly in their genetic and protein polymorphism, as well as in morphology. Some European L. serriola populations (e.g. from Scandinavia and United Kingdom/British Isles/) seems to be isolated and homogeneous; in contrast, populations occurring in Central Europe are very diverse and genetically overlapping.     

Comparison of aragonitic molluscan shell proteins

Acidic macromolecules, as a nucleation factor for mollusc shell formation, are a major focus of research. It remains unclear, however, whether acidic macromolecules are present only in calcified shell organic matrices, and which acidic macromolecules are crucial for the nucleation process by binding to chitin as structural components. To clarify these questions, we applied 2D gel electrophoresis and amino acid analysis to soluble shell organic matrices from nacre shell, non-nacre aragonitic shell and non-calcified squid shells. The 2D gel electrophoresis results showed that the acidity of soluble proteins differs even between nacre shells, and some nacre (Haliotis gigantea) showed a basic protein migration pattern. Non-calcified shells also contained some moderately acidic proteins. The results did not support the correlation between the acidity of soluble shell proteins and shell structure.     

Immobilization of yeast cells onto hydroxyalkyl methacrylate gels modified by spacers of different lengths

Summary The potential of hydroxyalkyl methacrylate gel as a support for yeast cell immobilization by covalent attachment was investigated with respect to the length of spacer used and the manner of its activation. Saccharomyces paradoxus cells were immobilized successfully onto glutaraldehyde activated glycyl-, -alanyl-and -aminocaproyl-derivatives of the above mentioned gel modified with hexamethylenediamine. Results suggest that covalent attachment via spacer is strongly influenced by cell surface characteristics.     

Nitrous acid deamination of conformationally inverted aminodeoxyhexopyranoses

Nitrous acid deamination of 2-amino-1,6-anhydro-2-deoxy-β-D-glucopyranose (1) in the presence of weakly acidic, cation-exchange resin gave 1,6:2,3-dianhydro-β-D-mannopyranose (3) and 2,6-anhydro-D-mannose (6), characterized, respectively, as the 4-acetate of 3 and the per-O-acetylated reduction product of 6, namely 2,3,4,6- tetra-O-acetyl-1,5-anhydro-D-mannitol, obtained in the ratio of 7:13. Comparative deaminatior of the 4-O-benzyl derivative of 1 led to similar qualitative results. Deamination of 3-amino-1,6-anhydro-3-deoxy-β-D-glucopyranose gave 1,6:2,3- and 1,6:3,4-dianhydro-β-D-allopyranose (13 and 16), characterized as the corresponding acetates, obtained in the ratio of 31:69, as well as the corresponding p-toluenesulfonates. Deamination of 4-amino-1,6-anhydro-4-deoxy-β-D-glucopyranose and of its 2-O-benzyl derivative gave the corresponding 1,6:3,4-D-galacto dianhydrides as the only detectable products. 2,5-Anhydro-D-glucose, characterized as the 1,3,4,6-tetra-O- acetyl derivative of the corresponding anhydropolyol, was obtained in 39% yield from the same deamination reaction performed on 2-amino-1,6-anhydro-2-deoxy-β-D- mannopyranose (24). In 90% acetic acid, the nitrous acid deamination of 24, followed by per-O-acetylation, gave only 1,3-4-tri-O-acetyl-2,5-anhydro-α-D-glucoseptanose. In the case of 1,6-anhydro-3,4-dideoxy-3,4-epimino-β-D-altropyranose, only the corresponding glycosene was formed, namely, 1,6-anhydro-3,4-dideoxy-β-D-threo--hex-3-enopyranose.     

Conformation of free and ribosome bound rRNAs from E.coli

The effect of protein moiety on the conformation of 16S and 23S RNA of the $\text{E.}\text{coli}$ ribosome has been studied by circular dichroic spectroscopy. Both rRNAs possess a comparable net content of ordered secondary structure which remains unchanged after association with ribosomal proteins into “core” particles or into complete 30S and 50S subunits, respectively. However, differences found in the stability and the cooperativity of melting of free and protein-associated rRNAs imply protein-caused variations in the distribution of the intramolecular hairpin stems and loops and/or changes in long range tertiary interactions which appear to be different for both rRNAs. While 23S RNA is maximally stabilized on the large subunit by the full set of proteins, 16S RNA on the complete small subunit shows lower stability but higher cooperativity in melting.     

Herpetomonas ztiplika n. sp. (Kinetoplastida: Trypanosomatidae): a parasite of the blood-sucking biting midge Culicoides kibunensis Tokunaga, 1937 (Diptera: Ceratopogonidae)

Herein, we describe the first case of a natural infection of biting midges by a kinetoplastid protozoan. Flagellates from a female Culicoides kibunensis captured in a bird's nest were introduced into culture and characterized by light and electron microscopy. However, because the morphological data were inconclusive, the novel endosymbiont-free trypanosomatid was assigned into Herpetomonas primarily on the basis of the 18S and 5S ribosomal RNA (rRNA) gene sequences.