Magnetite-based nanoparticles and nanocomposites for recovery of overloaded anaerobic digesters.

The effect of magnetite nanoparticles and nanocomposites (magnetite nanoparticles impregnated into graphene oxide) supplement on the recovery of overloaded laboratory batch anaerobic reactors was assessed using two types of starting inoculum: anaerobic granular sludge (GS) and flocculent sludge (FS). Both nanomaterials recovered methane production at a dose of 0.27 g/L within 40 days in GS.

Use of an automated respirometer for in situ chemical oxidation (ISCO) activator type and concentration selection.

In situ chemical oxidation (ISCO) is a popular remediation technique for hydrocarbon-contaminated soil and groundwater. A range of oxidising agents and activators are available for ISCO; however, selection is usually based on contaminant destruction which is time-consuming and impacted by sample heterogeneity based on 1-10 g sample contaminant analysis. In this paper, we demonstrate the use of an automated respirometer, measuring CO production, as a rapid and reliable approach for activator type and concentration selection.

Effect of initial moisture content and sample storage duration on compost stability using the ORG0020 dynamic respiration test.

Biological tests are widely used to assess composting process status and finished material stability. Although compost stability is known to be influenced by moisture content (MC) and storage duration, there is a lack of data supporting boundary limits for standardised testing. Using the ORG0020 dynamic respiration test we assessed the stability of materials from different commercial composting sites processing only green waste or mixed green and food waste.

Aerosol and bioaerosol particle size and dynamics from defective sanitary plumbing systems.

Aerosols are readily transported on airstreams through building sanitary plumbing and sewer systems, and those containing microbial pathogens (known as bioaerosols) are recognized as contributors to infection spread within buildings. When a defect occurs in the sanitary plumbing system that affects the system integrity, a cross-transmission route is created that can enable the emission of bioaerosols from the system into the building. These emission occurrences are characterized as short-burst events (typically <1 min in duration) which make them difficult to detect and predict.

Assessment of the use of compost stability as an indicator of alkane and aromatic hydrocarbon degrader abundance in green waste composting materials and finished composts for soil bioremediation application.

Green waste composting materials and finished composts were collected from different commercial ex situ composting sites all treating source segregated green waste feedstocks. Stability of each material was determined using the standard ORG0020 dynamic respiration test. To assess whether stability could be used as an indicator for the potential suitability of green waste composting materials and finished composts as amendments for soil bioremediation, comparison was made with alkane and aromatic hydrocarbon degrader abundance determined using a quantitative PCR (qPCR) approach.

Systems biology approach to elucidation of contaminant biodegradation in complex samples - integration of high-resolution analytical and molecular tools.

We present here a data-driven systems biology framework for the rational design of biotechnological solutions for contaminated environments with the aim of understanding the interactions and mechanisms underpinning the role of microbial communities in the biodegradation of contaminated soils. We have considered a multi-omics approach that employs novel in silico tools to combine high-throughput sequencing data (16S rRNA amplicons) with chemical data including high-resolution analytical data generated by comprehensive two-dimensional gas chromatography (GC × GC). To assess this approach, we have considered a matching dataset with both microbiological and chemical signatures available for samples from two former manufactured gas plant sites.

Natural marine bacteria as model organisms for the hazard-assessment of consumer products containing silver nanoparticles.

Scarce information is available regarding the fate and toxicology of engineered silver nanoparticles (AgNPs) in the marine environment, especially when compared to other environmental compartments. Hence, the antibacterial activity of the NM-300 AgNPs (OECD programme) and a household product containing colloidal AgNPs (Mesosilver) was investigated using marine bacteria, pure cultures and natural mixed populations (microcosm approach). Bacterial susceptibility to AgNPs was species-specific, with Gram negative bacteria being more resistant than the Gram positive species (NM-300 concentration used ranged between 0.

Batch anaerobic digestion of deproteinated malt whisky pot ale using different source inocula.

A novel process has been developed for the selective removal of protein from pot ale with recovered protein holding potential as a value-added by-product for the whisky industry. The purpose of this work was to assess the effect of deproteination on pot ale physicochemical characterisation and anaerobic digestion (AD) treatment. Pot ales were taken from five malt whisky distilleries and tested untreated, after centrifugation/filtration and after deproteination at laboratory or pilot scale.

Toxicity Testing of Pristine and Aged Silver Nanoparticles in Real Wastewaters Using Bioluminescent .

Impact of aging on nanoparticle toxicity in real matrices is scarcely investigated due to a lack of suitable methodologies. Herein, the toxicity of pristine and aged silver nanoparticles (Ag NPs) to a bioluminescent bioreporter was measured in spiked crude and final wastewater samples (CWs and FWs, respectively) collected from four wastewater treatment plants (WWTPs). Results showed lower toxicity of pristine Ag NPs in CWs than in FWs.

Pathogen cross-transmission via building sanitary plumbing systems in a full scale pilot test-rig.

The WHO Consensus Document on the epidemiology of the SARS epidemic in 2003, included a report on a concentrated outbreak in one Hong Kong housing block which was considered a 'super-spreading event'. The WHO report conjectured that the sanitary plumbing system was one transmission route for the virus. Empty U-traps allowed the aerosolised virus to enter households from the sewerage system.

Variability in physical contamination assessment of source segregated biodegradable municipal waste derived composts.

Physical contaminants (glass, metal, plastic and 'other') and stones were isolated and categorised from three finished commercial composts derived from source segregated biodegradable municipal waste (BMW). A subset of the identified physical contaminant fragments were subsequently reintroduced into the cleaned compost samples and sent to three commercial laboratories for testing in an inter-laboratory trial using the current PAS100:2011 method (AfOR MT PC&S). The trial showed that the 'other' category caused difficulty for all three laboratories with under reporting, particularly of the most common 'other' contaminants (paper and cardboard) and, over-reporting of non-man-made fragments.

Temporal dynamics of hot desert microbial communities reveal structural and functional responses to water input.

The temporal dynamics of desert soil microbial communities are poorly understood. Given the implications for ecosystem functioning under a global change scenario, a better understanding of desert microbial community stability is crucial. Here, we sampled soils in the central Namib Desert on sixteen different occasions over a one-year period.

Pseudomonas putida biofilm dynamics following a single pulse of silver nanoparticles.

Pseudomonas putida mono-species biofilms were exposed to silver nanoparticles (Ag NPs) in artificial wastewater (AW) under hydrodynamic conditions. Specifically, 48 h old biofilms received a single pulse of Ag NPs at 0, 0.01, 0.

Static, dynamic and inoculum augmented respiration based test assessment for determining in-vessel compost stability.

The purpose of this work was to evaluate compost (and related industry) stability tests given recent large-scale changes to feedstock, processing techniques and compost market requirements. Five stability tests (ORG0020, DR4, Dewar self-heating, oxygen update rate (OUR) and static respiration) were evaluated on composts from ten in-vessel composting sites. Spearman rank correlation coefficients were strong for the ORG0020, OUR and DR4 (both CO2 and O2 measurement), however, OUR results required data extrapolation for highly active compost samples.

Shifts in the metabolic function of a benthic estuarine microbial community following a single pulse exposure to silver nanoparticles.

The increasing use of silver nanoparticles (AgNPs) as a biocidal agent and their potential accumulation in sediments may threaten non-target natural environmental bacterial communities. In this study a microcosm approach was established to investigate the effects of well characterized OECD AgNPs (NM-300) on the function of the bacterial community inhabiting marine estuarine sediments (salinity 31‰). The results showed that a single pulse of NM-300 AgNPs (1 mg L(-1)) that led to sediment concentrations below 6 mg Ag kg(-1) dry weight inhibited the bacterial utilization of environmentally relevant carbon substrates.

Silver, zinc oxide and titanium dioxide nanoparticle ecotoxicity to bioluminescent Pseudomonas putida in laboratory medium and artificial wastewater.

Bacteria based ecotoxicology assessment of manufactured nanoparticles is largely restricted to Escherichia coli bioreporters in laboratory media. Here, toxicity effects of model OECD nanoparticles (Ag NM-300K, ZnO NM-110 and TiO2 NM-104) were assessed using the switch-off luminescent Pseudomonas putida BS566::luxCDABE bioreporter in Luria Bertani (LB) medium and artificial wastewater (AW). IC50 values ∼4 mg L(-1), 100 mg L(-1) and >200 mg L(-1) at 1 h were observed in LB for Ag NM-300K, ZnO NM-110 and TiO2 NM-104, respectively.

Two dimensional interferometric optical trapping of multiple particles and Escherichia coli bacterial cells using a lensed multicore fiber.

Two dimensional interferometric trapping of multiple microspheres and Escherichia coli has been demonstrated using a multicore fiber lensed with an electric arc fusion splicer. Light was coupled evenly into all four cores using a diffractive optical element. The visibility of the fringes and also the appearance of the lattice can be altered by rotating a half wave-plate.

CO₂ and O₂ respiration kinetics in hydrocarbon contaminated soils amended with organic carbon sources used to determine catabolic diversity.

Multiple substrate induced respiration (MSIR) assays which assess the response of soils to carbon source amendment are effective approaches to determine catabolic diversity of soils. Many assays are based on a single short term (<6 h) time point measurement and usually limited to CO2 production only. However, repeated measurements of both CO2 and O2 simultaneously can provide additional valuable information.

Potential benefit of surfactants in a hydrocarbon contaminated soil washing process: fluorescence spectroscopy based assessment.

Soil washing is an ex situ soil remediation treatment process. The purpose of soil washing is to clean the major gravel and sand fractions, concentrating contamination into the fine silt and clay fractions. The addition of surfactants can improve the efficiency of this method.

Mycorrhization helper bacteria: a case of specificity for altering ectomycorrhiza architecture but not ectomycorrhiza formation.

Mycorrhization helper bacteria (MHB), isolated from phylogenetically distinct ectomycorrhizal symbioses involving Lactarius rufus, Laccaria bicolor or Suillus luteus, were tested for fungus specificity to enhance L. rufus-Pinus sylvestris or L. bicolor-P.

Importance of mycorrhization helper bacteria cell density and metabolite localization for the Pinus sylvestris-Lactarius rufus symbiosis.

Mycorrhization helper bacteria, Paenibacillus sp. EJP73 and Burkholderia sp. EJP67, were used to study the importance of bacterial inoculum dose and bacterial derived soluble and volatile metabolites localization for enhancing mycorrhiza formation in the Pinus sylvestris-Lactarius rufus symbiosis, using a laboratory based microcosm.

A soil-based microbial biofilm exposed to 2,4-D: bacterial community development and establishment of conjugative plasmid pJP4.

A soil suspension was used as a source to initiate the development of microbial communities in flow cells irrigated with 2,4-dichlorophenoxyacetic acid (2,4-D) (25 microg ml(-1)). Culturable bacterial members of the community were identified by 16S rRNA gene sequencing and found to be members of the genera Pseudomonas, Burkholderia, Collimonas and Rhodococcus. A 2,4-D degrading donor strain, Pseudomonas putida SM1443 (pJP4::gfp), was inoculated into flow cell chambers containing 2-day old biofilm communities.