Factors that affect water column hydrocarbon concentrations have minor impacts on microbial responses following simulated diesel fuel spills.

Effects of season and mixing on hydrocarbon concentrations and the microbial community response was explored in a series of mesocosm experiments simulating surface spills of diesel into coastal waters. Mixing of any amount contributed to hydrocarbons entering the water column, but diesel fuel composition had a significant effect on hydrocarbon concentrations. Higher initial concentrations of aromatic hydrocarbons resulted in higher water column concentrations, with minimal differences among seasons due to high variability.

Metagenomic and metatranscriptomic responses of natural oil degrading bacteria in the presence of dispersants.

Oil biodegradation has been extensively studied in the wake of the deepwater horizon spill, but the application of dispersant to oil spills in marine environments remains controversial. Here, we report metagenomic (MG) and metatranscriptomic (MT) data mining from microcosm experiments investigating the oil degrading potential of Canadian west and east coasts to estimate the gene abundance and activity of oil degrading bacteria in the presence of dispersant. We found that the addition of dispersant to crude oil mainly favours the abundance of Thalassolituus in the summer and Oleispira in the winter, two key natural oil degrading bacteria.

Potential for Microbially Mediated Natural Attenuation of Diluted Bitumen on the Coast of British Columbia (Canada).

Western Canada produces large amounts of bitumen, a heavy, highly weathered crude oil. Douglas Channel and Hecate Strait on the coast of British Columbia are two water bodies that may be impacted by a proposed pipeline and marine shipping route for diluted bitumen (dilbit). This study investigated the potential of microbial communities from these waters to mitigate the impacts of a potential dilbit spill.

Chemical dispersants enhance the activity of oil- and gas condensate-degrading marine bacteria.

Application of chemical dispersants to oil spills in the marine environment is a common practice to disperse oil into the water column and stimulate oil biodegradation by increasing its bioavailability to indigenous bacteria capable of naturally metabolizing hydrocarbons. In the context of a spill event, the biodegradation of crude oil and gas condensate off eastern Canada is an essential component of a response strategy. In laboratory experiments, we simulated conditions similar to an oil spill with and without the addition of chemical dispersant under both winter and summer conditions and evaluated the natural attenuation potential for hydrocarbons in near-surface sea water from the vicinity of crude oil and natural gas production facilities off eastern Canada.

Comparison of Methods to Identify Pathogens and Associated Virulence Functional Genes in Biosolids from Two Different Wastewater Treatment Facilities in Canada.

The use of treated municipal wastewater residues (biosolids) as fertilizers is an attractive, inexpensive option for growers and farmers. Various regulatory bodies typically employ indicator organisms (fecal coliforms, E. coli and Salmonella) to assess the adequacy and efficiency of the wastewater treatment process in reducing pathogen loads in the final product.

Toxicogenomic effects of nano- and bulk-TiO2 particles in the soil nematode Caenorhabditis elegans.

The toxicity and toxicogenomics of selected anatase and rutile nanoparticles (NP) and bulk titanium dioxide (TiO2) particles were evaluated in the soil nematode Caenorhabditis elegans. Results indicated that bulk or nano-TiO2 particles were slightly toxic to soil nematode C. elegans, as measured by reproduction EC50 values ranging from 4 to 32 mg/L.

Analysis of the temporal expression of Trichoplusia ni single nucleopolyhedrovirus genes following transfection of BT1-Tn-5B1-4 cells.

Trichoplusia ni single nucleopolyhedrovirus (TnSNPV), a 134,394-bp double-stranded DNA group II Nucleopolyhedrovirus, is pathogenic to the lepidopteran T. ni. TnSNPV transcription is temporally regulated and divided into three promoter sequence-dependent classes (early, late and very late genes).

Dysregulated inflammatory response to Candida albicans in a C5-deficient mouse strain.

Experimental infection of inbred mouse strains with Candida albicans provides a good model system to identify host genetic determinants that regulate onset of, response to, and ultimate outcome of disseminated candidiasis. The A/J mouse strain is exquisitely sensitive to infection with C. albicans, while the C57BL/6J strain is relatively resistant, as measured by survival following intravenous injection of Candida blastospores.

Gene expression in HL60 granulocytoids and human polymorphonuclear leukocytes exposed to Candida albicans.

Candida albicans is an opportunistic human pathogen causing both superficial and disseminated diseases. It is a dimorphic fungus, switching between yeast and hyphal forms, depending on cues from its microenvironment. Hyphae play an important role in the pathogenesis of candidiasis.