Abstract

Mass spectrometry allows rapid and reliable identification and characterisation

of proteins and peptides in snake venoms. With the increasing availability

of transcriptomic and genomic data, there is a growing database of protein sequences

that is essential for protein identification. Snake venoms are analysed using a multi- dimensional proteomic approach known as ‚venomics‘. Proteins are first separated by

one- or two-dimensional gel electrophoresis or reversed-phase liquid chromatography.

The individual protein spots or fractions are digested enzymatically and the resulting

peptides are analysed by mass spectrometry. The proteins are identified by comparing

the mass spectra of the peptides with those in the database. High-performance mass

spectrometers allow the analysis of venoms even without prior separation of the protein

mixture. We have analysed the protein composition (proteome) of two European snake

venoms of greatest medical interest, the nose-horned viper ( Vipera a. ammodytes ) and

the common adder ( Vipera b. berus ). The nose-horned viper is the most venomous

European snake. Although its bite is rarely fatal, a human wictim often needs to be

observed in hospital and treated with an antivenom. The adder is the most widespread

European venomous snake and its bite causes milder symptoms than the bite of the

nose-horned viper in most cases. To explain the observed differences in the effects of the

two venoms at the molecular level, a proteomic study was performed. We also analysed

the proteome of the venom of the meadow viper ( Vipera ursinii ), the most threatened

snake species in Europe. It does not pose a threat to humans. In the wild, it feeds mainly

on insects, while in captivity it is fed on mice. A comparison of the proteome of the

venom of snakes in the wild and snakes in captivity showed clear differences. Thus,

the composition of snake venom is diet-dependent. Mass spectrometry is also a very

useful tool in the characterisation of antivenoms (antivenomics) to determine their

specificity and neutralising power.

Keywords

antivenomics, common adder, mass spectrometry, meadow viper, nose-horned viper, proteomics, snake venom, venomics, Vipera s. ammodytes , Vipera b. berus , ( Vipera ursinii )

Abstract

This contribution discusses the optical properties of different structures

of some herbaceous understorey plant species from temperate deciduous and mixed

forests. These forests are marked by annual dynamics of radiation level that is related

to the vegetation cycle of forest trees. During winter and early spring, the understorey

is exposed to full solar radiation, while later in the growing season radiation is limited

due to the closing of the tree storey. The plasticity of optical properties of photosynthetic

structures of understorey plants is directly related to their structural and biochemical

phenotypic plasticity that optimises harvesting and use of energy. The optimisation

of energy harvesting is also achieved by specific adaptations of green leaves, such

as variegation ( Pulmonaria officinalis , Cyclamen sp.), anthocyanic lower epidermis

( Cyclamen sp.), and by using structures other than green leaves for photosynthesis,

such as bracts ( Hacquetia epipactis ) and sepals ( Helleborus sp.). The optical proper ties

of these structures are similar to those of green leaves. The understanding of

optical responses of different structures contributes to the understanding of the forest

understorey functioning.

Keywords

bracts, leaves, light conditions, optical properties, sepals, temperate deciduous forest, understorey plants

Abstract

Holy water plays an important role in various religions. It is used for

baptisms, to bless people, places and objects. In Catholic churches, it is usually offered

in the holy water fonts at the entrance of the church. But it is also considered a source

of potential pathogens, such as Pseudomonas aeruginosa , Acinetobacter baumanii and

enterobacteria. To estimate the potential risk, we studied the composition and antimicrobial

resistance of bacteria in holy water from fonts and reservoirs of ten selected

Catholic churches in Ljubljana, Slovenia. Bacterial contamination of holy water from

fonts was moderate (10 2 - 10 5 CFU ml -1 ), but one to two orders of magnitude higher

than in reservoirs, probably due to frequent immersion of fingers in the water. Some

genera/species occurred only in fonts ( Acinetobacter beijerinckii , A. haemolyticus ,

Brevundimonas aurantiaca , B. mediterranea , Delftia , Kocuria , Sphingobacterium ,

Staphylococcus warneri ), while few fecal indicator bacteria were isolated. Isolated

bacteria have relatively low pathogenic potential, some of them are skin commensals.

Bacterial strains isolated in this study were susceptible to antibiotics. While according

to our results, the potential of holy water for spreading bacterial infections is modest,

to further limit the risks, water should be changed regularly, the fonts cleaned

thoroughly, and the water should not be brought in contact with the eyes, ingested or

aerosolized and inhaled.

Keywords

antibiotic resistance, bacteria, fonts, holy water, NaCl, Roman Catholic churches, pathogens

Abstract

Selection of genes that have not been horizontally transferred for prokaryote

phylogenetic studies is regarded as a challenging task. Internal transcribed spacer

of ribosomal genes (16S–23S ITS), microcystin synthetase genes ( mcy ), nitrogenase

( nifH ) and phycocyanin intergenic spacer ( PC-IGS ) are among the most used markers in

cyanobacteria. The region of the ribosomal genes has been considered stable, whereas

the nifH , mcyG and PC-IGS may have undergone horizontal transfer. To investigate

the occurrence of horizontal transfer of nifH , mcyG and PC-IGS , phylogenetic trees of

Aliinostoc strains Ay1375 and Me1355 were generated and compared. Phylogenetic

trees based on the markers were mostly congruent for PC-IGS , indicating a common

evolutionary history among ribosomal and phycocyanin genes with no evidence for

horizontal transfer of PC-IGS . Phylogenetic trees constructed from the nifH and 16S

rRNA genes were incongruent. Our results suggest that nifH has been transferred from

one cyanobacterium to another. Moreover, the low non-synonymous/synonymous mutation

ratio (Ka/Ks) was consistent with an ancient origin of the mcyG .

Keywords

16S–23S ITS, cyanobacteria, horizontal gene transfer, molecular phylogeny, phycocyanin, ribosomal genes