Eight new primer sets were designed for PCR detection of (i) mono-oxygenase and dioxygenase gene sequences involved in initial attack of bacterial aerobic BTEX degradation and of (ii) catechol 2,3-dioxygenase gene sequences responsible for meta-cleavage of the aromatic ring. The new primer sets allowed detection of the corresponding genotypes in soil with a detection limit of 10(3)-10(4) or 10(5)-10(6) gene copies g(-1) soil, assuming one copy of the gene per cell. The primer sets were used in PCR to assess the distribution of the catabolic genes in BTEX degrading bacterial strains and DNA extracts isolated from soils sampled from different locations and depths (vadose, capillary fringe and saturated zone) within a BTEX contaminated site. In both soil DNA and the isolates, tmoA-, xylM- and xylE1-like genes were the most frequently recovered BTEX catabolic genes. xylM and xylE1 were only recovered from material from the contaminated samples while tmoA was detected in material from both the contaminated and non-contaminated samples. The isolates, mainly obtained from the contaminated locations, belonged to the Actinobacteria or Proteobacteria (mainly Pseudomonas). The ability to degrade benzene was the most common BTEX degradation phenotype among them and its distribution was largely congruent with the distribution of the tmoA-like genotype. The presence of tmoA and xylM genes in phylogenetically distant strains indicated the occurrence of horizontal transfer of BTEX catabolic genes in the aquifer. Overall, these results show spatial variation in the composition of the BTEX degradation genes and hence in the type of BTEX degradation activity and pathway, at the examined site. They indicate that bacteria carrying specific pathways and primarily carrying tmoA/xylM/xylE1 genotypes, are being selected upon BTEX contamination.
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tmoA and related genes encode the alpha-subunit of the hydroxylase component of the major group (subgroup 1 of subfamily 2) of bacterial multicomponent mono-oxygenase enzyme complexes involved in aerobic benzene, toluene, ethylbenzene and xylene (BTEX) degradation. A PCR-denaturing gradient gel electrophoresis (DGGE) method was developed to assess the diversity of tmoA-like gene sequences in environmental samples using a newly designed moderately degenerate primer set suitable for that purpose. In 35 BTEX-degrading bacterial strains isolated from a hydrocarbon polluted aquifer, tmoA-like genes were only detected in two o-xylene degraders and were identical to the touA gene of Pseudomonas stutzeri OX1. The diversity of tmoA-like genes was examined in DNA extracts from contaminated and non-contaminated subsurface samples at a site containing a BTEX-contaminated groundwater plume. Differences in DGGE patterns were observed between strongly contaminated, less contaminated and non-contaminated samples and between different depths, suggesting that the diversity of tmoA-like genes was determined by environmental conditions including the contamination level. Phylogenetic analysis of the protein sequences deduced from the amplified amplicons showed that the diversity of TmoA-analogues in the environment is larger than suggested from described TmoA-analogues from cultured isolates, which was translated in the DGGE patterns. Although different positions on the DGGE gel can correspond to closely related TmoA-proteins, relationships could be noticed between the position of tmoA-like amplicons in the DGGE profile and the phylogenetic position of the deduced protein sequence.
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This report presents the highlights of the 7th European Meeting on Molecular Diagnostics held in Scheveningen, The Hague, The Netherlands, 12-14 October 2011. The areas covered included molecular diagnostics applications in medical microbiology, virology, pathology, hemato-oncology,clinical genetics and forensics. Novel real-time amplification approaches, novel diagnostic applications and new technologies, such as next-generation sequencing, PCR lectrospray-ionization TOF mass spectrometry and techniques based on the detection of proteins or other molecules, were discussed. Furthermore, diagnostic companies presented their future visions for molecular diagnostics in human healthcare.
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The denim industry faces many complex sustainability challenges and has been especially criticized for its polluting and hazardous production practices. Reducing resource use of water, chemicals and energy and changing denim production practices calls for collaboration between various stakeholders, including competing denim brands. There is great benefit in combining denim brands’ resources and knowledge so that commonly defined standards and benchmarks are developed and realized on a scale that matters. Collaboration however, and especially between competitors, is highly complex and prone to fail. This project brings leading denim brands together to collectively take initial steps towards improving the ecological sustainability impact of denim production, particularly by establishing measurements, benchmarks and standards for resource use (e.g. chemicals, water, energy) and creating best practices for effective collaboration. The central research question of our project is: How do denim brands effectively collaborate together to create common, industry standards on resource use and benchmarks for improved ecological sustainability in denim production? To answer this question, we will use a mixed-method, action research approach. The project’s research setting is the Amsterdam Metropolitan Area (MRA), which has a strong denim cluster and is home to many international denim brands and start-ups.
De recente toename in het aantal bedwantsen in de Westerse wereld leidt ertoe dat steeds meer mensen in contact komen met deze insecten. Vroege detectie is cruciaal voor een snelle bestrijding. Dit is echter lastig door de cryptische leefwijze van de bedwants, en vereist vaak destructieve maatregelen. In dit project onderzoeken HAS Hogeschool en BioMon of het haalbaar is om een bedwantsdetectiekit te ontwikkelen waarmee de aanwezigheid van bedwants DNA in ruimten bepaald kan worden door het nemen van een swab of stofzuigersample. Bovendien wordt onderzocht hoe dit product en deze dienst efficiënt op de markt gezet kan worden.
Met dit project ‘Bouwstenen voor avontuurlijk spelen’ onderzoeken we hoe avontuurlijke speelplekken effectief (her)ingericht kunnen worden om daarmee het speel- en beweeggedrag van kinderen te bevorderen. Dit doen we door het gedrag van spelende kinderen op recent ingerichte avontuurlijke speelplekken in kaart te brengen en daarmee succes- en faalfactoren en ontwerpcriteria voor avontuurlijke speelplekken te bepalen. Zo ondersteunen we de gemeenten bij het vormgeven van toekomstige interventies.
