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Martin Krsek

Publications and source records attributed to Martin Krsek.

3 recordsLinked to original sources

Chemical composition and antibacterial activity of the essential oil and the gum of Pistacia lentiscus Var. chia.

The essential oil and gum of Pistacia lentiscus var. chia, commonly known as the mastic tree, are natural antimicrobial agents that have found extensive uses in medicine in recent years. In this work, the chemical composition of mastic oil and gum was studied by GC-MS, and the majority of their components was identified. alpha-Pinene, beta-myrcene, beta-pinene, limonene, and beta-caryophyllene were found to be the major components. The antibacterial activity of 12 components of mastic oil and the oil itself was evaluated using the disk diffusion method. Furthermore, attempts were made to separate the essential oil into different fractions in order to have a better picture of the components responsible for its antibacterial activity. Several trace components that appear to contribute significantly to the antibacterial activity of mastic oil have been identified: verbenone, alpha-terpineol, and linalool. The sensitivity to these compounds was different for different bacteria tested (Escherichia coli, Staphylococcus aureus, and Bacillus subtilis), which suggests that the antibacterial efficacy of mastic oil is due to a number of its components working synergistically. The establishment of a correlation between the antibacterial activity of mastic oil and its components was the main purpose of this research. Mastic gum was also examined, but it proved to be more difficult to handle compared to the essential oil.

Acyclic Monoterpenes↗

Soil invertebrates disrupt carbon flow through fungal networks.

Annual carbon flux through soil respiration is ten times greater than fossil fuel combustion, but its component parts are poorly understood because they are the product of complex multitrophic interactions between soil organisms. A major component of carbon flux from plants to soil occurs through networks of symbiotic arbuscular mycorrhizal fungi. Here, using 13CO2 pulse labeling, we show that natural densities of the numerically dominant fungal feeding invertebrate Protaphorura armata (order Collembola) reduces 13C enrichment of mycorrhizosphere respiration by 32%. Our findings emphasize the importance of multitrophic interactions in regulating respiration of recent plant photosynthate from soil.

Animals↗

Resolving functional diversity in relation to microbial community structure in soil: exploiting genomics and stable isotope probing.

The microbial ecology of soil still presents a challenge to microbiologists attempting to establish the ways in which bacteria and fungi actively metabolise substrates, link into food webs and recycle plant and animal remains and provide essential nutrients for plants. Extraction and in situ analysis of rRNA has enabled identification of active taxa, and detection of mRNA has provided an insight into the expression of key functional genes in soil. Recent advances in genomic analysis and stable isotope probing are the first steps in resolving the linkage between structure and function in microbial communities.

Bacteria↗