Project description:Metagenome data from soil samples were collected at 0 to 10cm deep from 2 avocado orchards in Channybearup, Western Australia, in 2024. Amplicon sequence variant (ASV) tables were constructed based on the DADA2 pipeline with default parameters.
Project description:Metal oxide nanoparticles can exert adverse effects on humans and aquatic organisms. However, the toxic effects and mechanisms of MO-NPs are not clearly understood.We investigated the toxic effects and mechanisms of copper oxide, zinc oxide, and nickel oxide nanoparticles in Danio rerio using microarray analysis.
Project description:The natural biotope of Bacillus subtilis is the upper layer of soil where it grows as a biofilm. To mimic this physiological development and study the impact of nanoparticles during the formation of a biofilm in a contaminated soil, we have studied the proteomic response of the ancestral strain Bacillus subtilis 3610, which is able to form biofilm contrary to the 168 laboratory strain. The bacteria were grown on soft agar plates containing n-ZnO, n-TiO2 or ZnSO4 metal ion.
Project description:Despite the global importance of forests, it is virtually unknown how their soil microbial communities adapt at the phylogenetic and functional level to long term metal pollution. Studying twelve sites located along two distinct gradients of metal pollution in Southern Poland revealed that both community composition (via MiSeq Illumina sequencing of 16S rRNA genes) and functional gene potential (using GeoChip 4.2) were highly similar across the gradients despite drastically diverging metal contamination levels. Metal pollution level significantly impacted microbial community structure (p = 0.037), but not bacterial taxon richness. Metal pollution altered the relative abundance of specific bacterial taxa, including Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Firmicutes, Planctomycetes and Proteobacteria. Also, a group of metal resistance genes showed significant correlations with metal concentrations in soil, although no clear impact of metal pollution levels on overall functional diversity and structure of microbial communities was observed. While screens of phylogenetic marker genes, such as 16S rRNA, provided only limited insight into resilience mechanisms, analysis of specific functional genes, e.g. involved in metal resistance, appeared to be a more promising strategy. This study showed that the effect of metal pollution on soil microbial communities was not straightforward, but could be filtered out from natural variation and habitat factors by multivariate statistical analysis and spatial sampling involving separate pollution gradients.
Project description:The toxicity of silver and zinc oxide nanoparticles is hypothesised to be mediated by dissolved metal ions and cerium dioxide nanoparticles (CeO2 NPs) are hypothesised to induce toxicity specifically by oxidative stress dependant on their surface redox state. To test these hypotheses, RNAseq was applied to characterise the molecular responses of cells to metal nanoparticle and metal ion exposures. The human epithelial lung carcinoma cell line A549 was exposed to different CeO2 NPs with different surface charges, micron-sized and nano-sized silver particles and silver ions, micron-sized and nano-sized zinc oxide particles and zinc ions, or control conditions, for 1 hour, 6 hours and 24 hours. Concentrations were the lower of either EC20 or 128 micrograms/mL. Transcriptional responses were characterised by RNAseq transcriptomics using an Illumina HiSeq2500 .
Project description:This study examined how transcriptomics tools can be included in a Triad-based soil quality assessment to assess the toxicity of soils from river banks polluted by metals. To that end we measured chemical soil properties and used the standardized ISO guideline for ecotoxicological tests and a newly developed microarray for gene expression in the indicator soil arthropod, Folsomia candida. Microarray analysis revealed that the oxidative stress response pathway was significantly affected in all soils except one. The data indicate that changes in cell redox homeostasis are a significant signature of metal stress. Finally, 32 genes showed significant dose-dependent expression with metal concentrations. They are promising genetic markers providing an early indication of the need for higher tier testing in soil quality. One of the least polluted soils showed toxicity in the bioassay that could be removed by sterilization. The gene expression profile for this soil did not show a metal-related signature, confirming that another factor than metals (most likely of biological origin) caused the toxicity. This study demonstrates the feasibility and advantages of integrating transcriptomics into Triad-based soil quality assessment. Combining molecular and organismal life-history trait’s stress responses helps identifying causes of adverse effect in bioassays. Further validation is needed for verifying the set of genes with dose-dependent expression patterns linked with toxic stress.