Q120580033
Dotaz
Zobrazit nápovědu
Changes in the abundance of bacteria and fungi and in the composition of bacterial communities during primary succession were investigated in a brown coal mine deposit area near Sokolov, the Czech Republic, using phospholipid fatty acids analysis, microarray and 16S rRNA gene sequencing. The study considered a chronosequence of sites undergoing spontaneous succession: 6-, 12-, 21- and 45-year-old and a 21-year-old site revegetated with Alnus glutinosa. During succession, organic carbon and the total nitrogen content increased while the pH and the C/N ratio decreased. Microbial biomass and bacterial diversity increased until 21 years and decreased later; bacteria dominated over fungi in the initial and late phases of succession. Bacterial community composition of the 6-year-old site with no vegetation cover largely differed from the older sites, especially by a higher content of Gammaproteobacteria, Cyanobacteria and some Alphaproteobacteria. Bacteria belonging to the genera Acidithiobacillus, Thiobacillus and related taxa, the CO(2) and N(2) fixers, dominated the community at this site. In the later phases, bacterial community development seemed to reflect more the changes in soil nutrient content and pH than vegetation with a decrease of Actinobacteria and an increase of Acidobacteria. The site revegetated with A. glutinosa resembled the 45-year-old primary succession site and exhibited an even lower pH and C/N ratio, indicating that recultivation is able to accelerate soil development.
- MeSH
- Acidobacteria MeSH
- Actinobacteria genetika růst a vývoj MeSH
- Alphaproteobacteria genetika růst a vývoj MeSH
- Bacteria klasifikace genetika růst a vývoj MeSH
- biodiverzita MeSH
- biomasa MeSH
- DNA bakterií analýza MeSH
- dusík analýza metabolismus MeSH
- fylogeneze MeSH
- geny rRNA MeSH
- houby genetika růst a vývoj MeSH
- molekulární sekvence - údaje MeSH
- monitorování životního prostředí MeSH
- půda chemie MeSH
- půdní mikrobiologie MeSH
- RNA ribozomální 16S genetika MeSH
- sekvence nukleotidů MeSH
- sinice genetika růst a vývoj MeSH
- těžba uhlí MeSH
- uhlí MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Ergosterol, a biomarker of living saprotrophic fungi, was obtained from soil by microwave-assisted extraction and determined by GC-MS-MS, HPLC, and GC-FID. The GC-MS-MS technique was used to monitor fungal biomass in the soils differently impacted by overwintering cattle. The amount of ergosterol in soil increased from 0.93 ± 0.34 to 29.28 ± 3.07 ?g g?1 of soil. The detection limits in GC-MS-MS and HPLC methods were ca. ten times lower than in GC-FID. Whereas GC-MS-MS is the best method for monitoring the complex sterol profile in the environment, the selective MS-MS mode allowed the determination of ergosterol in complex matrices by elimination of coeluting peaks. The enrichment of cattleimpacted soils in non-fungal sterols (campesterol, stigmaserol and ß-sitosterol) and stanols (ergostanol, sitostanol) was due to digested plant materials and rumen microflora, suggesting significant biochemical changes in the pasture soils under study.
The molecular diversity of Archaea in a bat guano pile in Cave Domica (Slovakia), temperate cave ecosystem with significant bat colony (about 1600 individuals), was examined. The guano pile was created mainly by an activity of the Mediterranean horseshoe bat (Rhinolophus euryale) and provides a source of organic carbon and other nutrients in the oligotrophic subsurface ecosystem. The upper and the basal parts of guano surface were sampled where the latter one had higher pH and higher admixture of limestone bedrock and increased colonization of invertebrates. The relative proportion of Archaea determined using CARD-FISH in both parts was 3.5-3.9 % (the basal and upper part, respectively). The archaeal community was dominated by non-thermophilic Crenarchaeota (99 % of clones). Phylogenetic analysis of 115 16S rDNA sequences revealed the presence of Crenarchaeota previously isolated from temperate surface soils (group 1.1b, 62 clones), deep subsurface acid waters (group 1.1a, 52 clones) and Euryarchaeota (1 clone). Four of the analyzed sequences were found to have little similarity to those in public databases. The composition of both archaeal communities differed, with respect to higher diversity of Archaea in the upper part of the bat guano pile. High diversity archaeal population is present in the bat guano deposit and consists of both soil- and subsurface-born Crenarchaeota.
- MeSH
- Archaea genetika izolace a purifikace klasifikace MeSH
- biodiverzita MeSH
- Chiroptera mikrobiologie MeSH
- DNA archebakterií genetika MeSH
- ekosystém MeSH
- feces chemie mikrobiologie MeSH
- financování organizované MeSH
- fylogeneze MeSH
- molekulární sekvence - údaje MeSH
- ribozomální DNA genetika MeSH
- RNA ribozomální 16S genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Geografické názvy
- Slovenská republika MeSH
Membrane fluidity adaptation to the low growth temperature in Bacillus subtilis involves two distinct mechanisms: (1) long-term adaptation accomplished by increasing the ratio of anteiso- to iso-branched fatty acids and (2) rapid desaturation of fatty acid chains in existing phospholipids by induction of fatty acid desaturase after cold shock. In this work we studied the effect of medium composition on cold adaptation of membrane fluidity. Bacillus subtilis was cultivated at optimum (40 degrees C) and low (20 degrees C) temperatures in complex medium with glucose or in mineral medium with either glucose or glycerol. Cold adaptation was characterized by fatty acid analysis and by measuring the midpoint of phospholipid phase transition T(m) (differential scanning calorimetry) and membrane fluidity (DPH fluorescence polarization). Cells cultured and measured at 40 degrees C displayed the same membrane fluidity in all three media despite a markedly different fatty acid composition. The T(m) was surprisingly the highest in the case of a culture grown in complex medium. On the contrary, cultivation at 20 degrees C in the complex medium gave rise to the highest membrane fluidity with concomitant decrease of T(m) by 10.5 degrees C. In mineral media at 20 degrees C the corresponding changes of T(m) were almost negligible. After a temperature shift from 40 to 20 degrees C, the cultures from all three media displayed the same adaptive induction of fatty acid desaturase despite their different membrane fluidity values immediately after cold shock.
