Degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) by fungi originating from Vietnam.

Three different fungi were tested for their ability to degrade 2,4-dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid and for the role of laccases and cytochromes P450-type in this process. We studied a white-rot fungus Rigidoporus sp. FMD21, which has a high laccase activity, for its efficiency to degrade these herbicides.

Molecular mechanisms of zinc toxicity in the potworm Enchytraeus crypticus, analysed by high-throughput gene expression profiling.

Zinc (Zn) is known to be relatively toxic to some soil-living invertebrates including the ecologically important enchytraeid worms. To reveal the molecular mechanisms of zinc toxicity we assessed the gene expression profile of Enchytraeus crypticus (Enchytraeidae), exposed to the reproduction effect concentrations EC and EC, over 4 consecutive days, using a high-throughput microarray (species customized). Three main mechanisms of toxicity to Zn were observed: 1) Zn trafficking (upregulation of zinc transporters, a defence response to regulate the cellular zinc level), 2) oxidative stress (variety of defence mechanisms, triggered by Reactive Oxygen Species (ROS)), and 3) effects on the nervous system (possibly the primary lesion explaining the avoidance behaviour and also why enchytraeids are relatively susceptible to Zn).

Elucidating fungal Rigidoporus species FMD21 lignin-modifying enzyme genes and 2,3,7,8-tetrachlorodibenzo-p-dioxin degradation by laccase isozymes.

White-rot fungus Rigidoporus sp. FMD21 is a lignin-modifying enzyme producing fungus that can degrade dioxin. Extracellular enzymes from FMD21 include laccase and manganese peroxidase which are promising enzymes for myco-remediation because of their wide substrate specificity and mild catalysis conditions.

Characterization of 2,3,7,8-tetrachlorodibenzo-p-dioxin biodegradation by extracellular lignin-modifying enzymes from ligninolytic fungus.

Ligninolytic fungi secrete extracellular lignin-modifying enzymes (LME) that degrade plant polymers for fungal nutrition but that are, because of their broad substrate specificity, also applicable for the degradation of many hazardous pollutants. Laccase is one of the most well characterized LME and is involved in the removal and degradation of recalcitrant aromatic compounds with or without the assistance of laccase-mediators. The Ligninolytic fungus Rigidoporus sp.

Species-specific transcriptomic responses in Daphnia magna exposed to a bio-plastic production intermediate.

Hydroxymethylfurfural (HMF) is a plant-based chemical building block that could potentially substitute petroleum-based equivalents, yet ecotoxicological data of this compound is currently limited. In this study, the effects of HMF on the reproduction and survival of Daphnia magna were assessed through validated ecotoxicological tests. The mechanism of toxicity was determined by analysis of transcriptomic responses induced by exposure to different concentrations of HMF using RNA sequencing.

Population-specific transcriptional differences associated with freeze tolerance in a terrestrial worm.

is a terrestrial earthworm widespread along the coasts of northern Europe and the Arctic. This species tolerates freezing of body fluids and survives winters in a frozen state. Their acclimatory physiological mechanisms behind freeze tolerance involve increased fluidity of membrane lipids during cold exposure and accumulation of cryoprotectants (glucose) during the freezing process.

Draft Genome Sequence of VU-DES13, Isolated from (Collembola: Entomobryidae).

We present here the draft genome of VU-DES13, which was isolated from the midgut of the soil-living springtail Previous research revealed the presence of gene clusters for the biosynthesis of various secondary metabolites, including β-lactam antibiotics, in the host's genome. The genome data are discussed in the light of the antimicrobial properties against fungi and oomycetes and a high level of β-lactam resistance of the isolate.

Mechanisms of phenanthrene toxicity in the soil invertebrate, Enchytraeus crypticus.

Polycyclic aromatic hydrocarbons (PAHs) continue to cause environmental challenges as a result of their release into the environment by a great variety of anthropogenic activities and their accumulation in soils. Studies were conducted on the toxicological effect of the model PAH phenanthrene using the soil invertebrate model Enchytraeus crypticus at the individual, tissue, and molecular levels. Animals were exposed for 2 d and 21 d to phenanthrene concentrations corresponding to the (previously estimated) 3-wk effective concentration, 10% (EC10) and EC50 for effects on reproduction.

Combined Transcriptomics Analysis for Classification of Adverse Effects As a Potential End Point in Effect Based Screening.

Environmental risk assessment relies on the use of bioassays to assess the environmental impact of chemicals. Gene expression is gaining acceptance as a valuable mechanistic end point in bioassays and effect-based screening. Data analysis and its results, however, are complex and often not directly applicable in risk assessment.

Transcriptome assembly and microarray construction for Enchytraeus crypticus, a model oligochaete to assess stress response mechanisms derived from soil conditions.

Background: The soil worm Enchytraeus crypticus (Oligochaeta) is an ecotoxicology model species that, until now, was without genome or transcriptome sequence information. The present research aims at studying the transcriptome of Enchytraeus crypticus, sampled from multiple test conditions, and the construction of a high-density microarray for functional genomic studies.

Results: Over 1.

Integrating transcriptomics into triad-based soil-quality assessment.

The present study examined how transcriptomics tools can be included in a triad-based soil-quality assessment to assess the toxicity of soils from riverbanks polluted by metals. To that end, the authors measured chemical soil properties and used the International Organization for Standardization 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.

A functional isopenicillin N synthase in an animal genome.

Horizontal transfer of genes is widespread among prokaryotes, but is less common between microorganisms and animals. Here, we present evidence for the presence of a gene encoding functional isopenicillin N synthase, an enzyme in the β-lactam antibiotics biosynthesis pathway, in the genome of the soil-living collembolan species, Folsomia candida (FcIPNS). At present, this gene is only known from bacteria and fungi, as is the capacity to produce β-lactam antibiotics.

The influence of long-term copper contaminated agricultural soil at different pH levels on microbial communities and springtail transcriptional regulation.

Copper has long been applied for agricultural practises. Like other metals, copper is highly persistent in the environment and biologically active long after its use has ceased. Here we present a unique study on the long-term effects (27 years) of copper and pH on soil microbial communities and on the springtail Folsomia candida an important representative of the soil macrofauna, in an experiment with a full factorial, random block design.

Transcriptional plasticity of a soil arthropod across different ecological conditions.

Ecological functional genomics, dealing with the responses of organisms to their natural environment is confronted with a complex pattern of variation and a large number of confounding environmental factors. For gene expression studies to provide meaningful information on conditions deviating from normal, a baseline or normal operating range (NOR) response needs to be established which indicates how an organism's transcriptome reacts to naturally varying ecological factors. Here we determine the transcriptional plasticity of a soil arthropod, Folsomia candida, exposed to various natural environments, as part of a first attempt in establishing such a NOR.

The effect of soil pH and temperature on Folsomia candida transcriptional regulation.

Differences in abiotic factors like temperature and soil pH can have a significant physiological impact on soil dwelling invertebrates and may confound results in ecotoxicological testing. In this study we exposed Folsomia candida to a range of two abiotic stress treatments (pH and temperature) for 3 days and measured gene expression of a panel of nine stress response genes with real-time Q-PCR. The exposure to different pH values had a minimal effect on the expression of the nine selected genes: only V-ATPase expression was significantly increased due to decreasing pH.

Reference genes for QRT-PCR tested under various stress conditions in Folsomia candida and Orchesella cincta (Insecta, Collembola).

Background: Genomic studies measuring transcriptional responses to changing environments and stress currently make their way into the field of evolutionary ecology and ecotoxicology. To investigate a small to medium number of genes or to confirm large scale microarray studies, Quantitative Reverse Transcriptase PCR (QRT-PCR) can achieve high accuracy of quantification when key standards, such as normalization, are carefully set. In this study, we validated potential reference genes for their use as endogenous controls under different chemical and physical stresses in two species of soil-living Collembola, Folsomia candida and Orchesella cincta.

Gene expression analysis of collembola in cadmium containing soil.

Increasing concern about pollution of our environment calls for advanced and rapid methods to estimate ecological toxicity. The use of gene expression microarrays in environmental studies can potentially meet this challenge. We present a novel method to examine soil toxicity.

Collembase: a repository for springtail genomics and soil quality assessment.

Background: Environmental quality assessment is traditionally based on responses of reproduction and survival of indicator organisms. For soil assessment the springtail Folsomia candida (Collembola) is an accepted standard test organism. We argue that environmental quality assessment using gene expression profiles of indicator organisms exposed to test substrates is more sensitive, more toxicant specific and significantly faster than current risk assessment methods.