Charles W Greer

Charles W Greer
McGill University | McGill · Department of Natural Resource Sciences

Ph.D.

About

663
Publications
62,350
Reads
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13,588
Citations
Introduction
Charles W Greer works at the National Research Council Canada in the Energy, Mining and Environment Research Centre. He is also and Adjunct Professor in the Department of Natural Resource Sciences, McGill University. Charles does research in biodegradation and bioremediation of environmental pollutants, biotechnology, microbial ecology, microbiology and environmental genomics.
Additional affiliations
September 2014 - present
Université de Sherbrooke
Position
  • Professor (Associate)
November 1992 - present
McGill University
Position
  • Professor (Associate)
March 1987 - present
National Research Council Canada
Position
  • Group Leader

Publications

Publications (663)
Article
Draft whole-genome sequences of a coculture are presented. One component was a polar cyanobacterium, Leptolyngbya sp. strain Cla-17. The second was a heterotrophic bacterium, Flavobacterium saccharophilum , found in the phycosphere of the cyanobacterium.
Article
Growing concerns over the risk of accidental releases of oil into the marine environment have emphasized our need to improve both oil spill preparedness and response strategies. Among the available spill response options, dispersants offer the advantages of breaking oil slicks into small oil droplets and promoting their dilution, dissolution, and b...
Article
The biodegradation of dispersed crude oil in the ocean is relatively rapid (a half-life of a few weeks). However, it is often much slower on shorelines, usually attributed to low moisture content, nutrient limitation, and higher oil concentrations in beaches than in dispersed plumes. Another factor may be the increased salinity of the upper interti...
Preprint
In shotgun metagenomics (SM), the state of the art bioinformatic workflows are referred to as high resolution shotgun metagenomics (HRSM) and require intensive computing and disk storage resources. While the increase in data output of the latest iteration of high throughput DNA sequencing systems can allow for unprecedented sequencing depth at a mi...
Article
Full-text available
Oil spills in coastal waters can have devastating impacts on local ecosystems, from the microscopic base through to mammals and seabirds. Increasing transport of diluted bitumen, has led to concerns about how this novel product might impact coastal ecosystems. A mesocosm study determined that the type of diluent and the season can affect the concen...
Article
Full-text available
The neurotoxic alkaloid β-N-methyl-amino-l-alanine (BMAA) and related isomers, including N-(2-aminoethyl glycine) (AEG), β-amino-N-methyl alanine (BAMA), and 2,4-diaminobutyric acid (DAB), have been reported previously in cyanobacterial samples. However, there are conflicting reports regarding their occurrence in surface waters. In this study, we e...
Article
Natural attenuation is an important process for oil spill management in marine environments. Natural attenuation affects the fate of oil by physical, chemical, and biological processes, which include evaporation, dispersion, dissolution, photo-oxidation, emulsification, oil particle aggregation, and biodegradation. This review examines the cumulati...
Article
Full-text available
Greenhouse gas (GHG) emissions from Arctic permafrost soils create a positive feedback loop of climate warming and further GHG emissions. Active methane uptake in these soils can reduce the impact of GHG on future Arctic warming potential. Aerobic methane oxidizers are thought to be responsible for this apparent methane sink, though Arctic represen...
Article
The global increase in marine transportation of dilbit (diluted bitumen) can increase the risk of spills, and the application of chemical dispersants remains a common response practice in spill events. To reliably evaluate dispersant effects on dilbit biodegradation over time, we set large-scale (1500 mL) microcosms without nutrients addition using...
Article
Sea ice loss is opening shipping routes in Canada's Northwest Passage, increasing the risk of an oil spill. Harnessing the capabilities of endemic microorganisms to degrade oil may be an effective remediation strategy for contaminated shorelines; however, limited data exists along Canada's Northwest Passage. In this study, hydrocarbon biodegradatio...
Article
Oil spilled in the Arctic may drift into ice-covered areas and become trapped until the ice melts. To determine if exposure to oil during freezing may have a priming effect on degradation of the oil, weathered dispersed oil (2-3 mg/L) was frozen into solid ice for 200 days at -10 °C, then melted and incubated for 64 days at 4 °C. No degradation was...
Article
Full-text available
Anthropogenic activities release large amounts of nitrogen (N) and phosphorus (P) nutrients into the environment. Sources of nutrients include surface and sub-surface runoffs from agricultural practices with the application of chemical fertilizers and manure as well as combined sewer overflows (CSOs). Nutrient runoffs contribute to the eutrophicati...
Article
Microbial communities are an important aspect of overall riverine ecology; however, appreciation of the effects of anthropogenic activities on unique riverine microbial niches, and how the collection of these samples affects the observed diversity and community profile is lacking. We analyzed prokaryotic and eukaryotic communities from surface wate...
Article
Full-text available
Douglas Channel and the adjacent Hecate Strait (British Columbia, Canada) are part of a proposed route to ship diluted bitumen (dilbit). This study presents how two types of dilbit naturally degrade in this environment by using an in situ microcosm design based on dilbit-coated beads. We show that dilbit-associated n-alkanes were microbially biodeg...
Article
Heavy crude oil (HCO) pollution has gained global attention, but traditional bioremediating practices demonstrate limited effectiveness. This study developed magnetic nanoparticles decorated bacteria (MNPB) using an oil-degrading and biosurfactant-producing Rhodococcus erythropolis species and identified a novel access-dispersion-recovery strategy...
Article
It is thought that modern wheat genotypes have lost their capacity to associate with soil microbes that would help them acquire nutrients from the soil. To test this hypothesis, ten ancestral and modern wheat genotypes were seeded in a field experiment under low fertilization conditions. The rhizosphere soil was collected, its DNA extracted and sub...
Article
Biosurfactant-based dispersants (BBDs) may be more effective, cost-efficient and environmentally friendly than dispersants currently used for oil spill response. An improved understanding of BBD performance is needed to advance their development and commercial use. In this study, the ability of four BBDs, i.e. sufactins, trehalose lipids, rhamnolip...
Article
Full-text available
Climate change, the opening of the northwest passage, the production and transportation of oil reserves in addition to the large size and number of ocean-going vessels, are putting all Canada's oceans at an elevated risk for an oil spill. Responses to marine oil spills include physical (skimming and recovery), chemical (dispersants, herders) and bi...
Article
Full-text available
1141488 Production of bitumen from oil sands is predicted to rise over the next decade. Some of this increased production will be transported to coastal areas for export. While some product will be transported via rail, the majority is likely to be transported through pipelines as diluted bitumen. This unconventional oil product is a mixture of the...
Article
The salinity of the upper parts of seashores can become higher than seawater due to evaporation between tidal inundations. Such hypersaline ecosystems, where the salinity can reach up to eight-fold higher than that of seawater (30-35 g/L), can be contaminated by oil spills. Here we investigate whether such an increase has inhibitory effects on oil...
Article
Drinking water producers continuously develop innovative treatment processes to effectively remove organic micropollutants from raw water. Biological ion-exchange (BIEX) water treatment is one of these new techniques under development and showing great potential. In order to investigate if biodegradation is highly involved in such a removal techniq...
Article
Full-text available
Purpose Mining activities have negative effects on soil characteristics and can result in low pH, high heavy metal content, and limited levels of essential nutrients. A tailings storage area located in northwestern Québec showed natural colonization by plants from the adjacent natural environment. The objective of the study was to determine the mai...
Article
Full-text available
Alkane biosynthesis by polar cyanobacteria has not yet been reported. We present here the draft whole-genome sequence of an alkane-synthesizing polar cyanobacterium, Pseudanabaena biceps strain O-153. The genes coding for the two key enzymes involved in the alkane biosynthetic pathway were found contiguously in the genome.
Article
Full-text available
Plant-microbe associations are increasingly recognized as an inextricable part of plant biology and biogeochemistry. Microbes play an essential role in the survival and development of plants, allowing them to thrive in diverse environments. The composition of the rhizosphere soil microbial communities is largely influenced by edaphic conditions and...
Article
Hypersaline environments are found around the world, above and below ground, and many are exposed to hydrocarbons on a continuous or a frequent basis. Some surface hypersaline environments are exposed to hydrocarbons because they have active petroleum seeps while others are exposed because of oil exploration and production, or nearby human activiti...
Article
Full-text available
As ice extent in the Arctic is declining, oil and gas activities will increase, with higher risk of oil spills to the marine environment. To determine biotransformation of dispersed weathered oil in newly formed ice, oil dispersions (2–3 ppm) were incubated in a mixture of natural seawater and frazil ice for 125 days at −2 °C. Dispersed oil in seaw...
Article
Full-text available
Intestinal microbial communities from 362 anadromous Arctic char (Salvelinus alpinus) from the high Arctic Kitikmeot region, Nunavut, Canada, were characterized using high‐throughput 16S rRNA gene sequencing. The resulting bacterial communities were compared across four seasonal habitats that correspond to different stages of annual migration. Arct...
Article
Full-text available
Manufactured Zn oxide nanoparticle (ZnO-NP) are extensively used world-wide in personal care and industrial products and are important contaminants of aquatic environments. To understand the overall impact of ZnO-NP contamination on aquatic ecosystems, investigation of their toxicity on aquatic biofilms is of particular consequence, given biofilms...
Article
Heavy crude oil transportation over land is increasing, yet the ecological impacts of spills, particularly of diluted bitumen, in freshwater environments remain poorly understood. We simulated spills of diluted bitumen in 1400 L land-based mesocosms containing water and sediments from a boreal, oligotrophic lake and monitored the response of natura...
Article
Mining activities have significant environmental impacts, such as the production of acid mine drainage and the typical absence of vegetation on mine tailings whose absence can facilitate the migration of metals to adjacent ecosystems. We investigated the metal and metalloid composition of plants and substrates on, and near a former gold mine site t...
Article
Transformative advances in metagenomics are providing an unprecedented ability to characterize the enormous diversity of microorganisms and invertebrates sustaining soil health and water quality. These advances are enabling a better recognition of the ecological linkages between soil and water, and the biodiversity exchanges between these two reser...
Article
Full-text available
There is public concern about the behaviour of spilled diluted bitumen (dilbit) in marine and estuarine waters. We provide a preliminary assessment of the results of laboratory experiments and models, in the context of environmental conditions in the coastal waters of British Columbia. Most dilbit spilled within this region would likely float at th...
Article
Increased economic activity in the Arctic may increase the risk of oil spills. Yet, little is known about the degradation of oil spills by solar radiation and the impact of nutrient limitation on oil biodegradation under Arctic conditions. We deployed adsorbents coated with thin oil films for up to 4 months in a fjord in SW Greenland to simulate an...
Chapter
Since the 2010 Deepwater Horizon oil well blowout in the Gulf of Mexico, there has been renewed interest in the biology of oil-degrading bacterial communities. One of the research focuses of our group is to use nucleic acid sequencing-based approaches to investigate the potential of indigenous bacteria to naturally metabolize hydrocarbons in the co...
Poster
Ice algae play a critical role in primary production and serve as part of the base of the polar food web. An emerging group of ice-binding proteins produced by bacteria has recently been discovered that enables bacteria to adhere to the surface of ice as well as photosynthetic diatoms. In terms of ecological significance, this symbiotic process inv...
Article
Full-text available
Microcystis is a genus of freshwater cyanobacteria, which causes harmful blooms in ecosystems worldwide. Some Microcystis strains produce harmful toxins such as microcystin, impacting drinking water quality. Microcystis colony morphology, rather than genetic similarity, is often used to classify Microcystis into morphospecies. Yet colony morphology...
Article
Microbial metabolism of the thawing organic carbon stores in permafrost results in a positive feedback loop of greenhouse gas emissions. CO2 and CH4 fluxes and the associated microbial communities in Arctic cryosols are important in predicting future warming potential of the Arctic. We demonstrate that topology had an impact on CH4 and CO2 flux at...
Article
Full-text available
Climate warming and subsequent permafrost thaw may result in organic carbon and nutrient stores being metabolized by microbial communities, resulting in a positive feedback loop of greenhouse gas (GHG) soil emissions. As the third most important GHG, understanding nitrous oxide (N 2 O) flux in Arctic mineral ice-wedge polygon cryosols and its relat...
Article
Water tracks in the Antarctic Dry Valleys are dark linear features of increased soil moisture that flow downslope over the spring and summer, providing a source of moisture in a cold-arid desert. They are typically sourced from melting snow, ground ice, and deliquescence (Levy et al., 2011 ). This research presents the first in-depth study of the a...
Article
Surficial application of waste glycerol (WG)for enhanced bioremediation was tested in situ at an old military range site to address hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)contaminated groundwater. This treatment was effective in inducing strong reducing conditions (range: −4 to −205 mV)and increasing the concentrations of organic carbon (from...
Article
Full-text available
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 w...
Article
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 ea...
Article
Full-text available
Many plants have natural partnerships with microbes that can boost their nitrogen (N) and/or phosphorus (P) acquisition. To assess whether wheat may have undiscovered associations of these types, we tested if N/P-starved Triticum aestivum show microbiome profiles that are simultaneously different from those of N/P-amended plants and those of their...
Preprint
Full-text available
Microcystis is a genus of freshwater cyanobacteria which causes harmful blooms in ecosystems worldwide. Some Microcystis strains produce harmful toxins such as microcystin, impacting drinking water quality. Microcystis colony morphology, rather than genetic similarity, is often used to classify Microcystis into morphospecies. However, colony morpho...
Preprint
Full-text available
Many plants have natural partnerships with microbes that can boost their nitrogen (N) and/or phosphorus (P) acquisition. To assess whether wheat may have undiscovered associations of these types, we tested if N/P-starved Triticum aestivum show microbiome profiles that are simultaneously different from those of N/P-amended plants and those of their...
Article
Full-text available
Canola is one of the most economically important crops in Canada, and the root and rhizosphere microbiomes of a canola plant likely impact its growth and nutrient uptake. The aim of this study was to determine whether canola has a core root microbiome (i.e., set of microbes that are consistently selected in the root environment), and whether this i...
Data
Biodiversity indices [Chao1, Simpson's reciprocal (Simpson R), and evenness] of archaeal assemblages based on the operational taxonomic units (OTUs) of 16S rRNA fragments. The figure shows the comparisons between crops (left) and canola treatments (right). The canola treatments were canola grown as recommended (Can_RE), canola fertilized at 150% of...
Data
The raw sequencing counts of each sample for bacteria, fungi and archaea by MiSeq Sequencing.
Data
Rarefaction curves based on Good's coverage per sample of (A) bacterial 16S rRNA, (B) fungal internal transcribed spacer (ITS), and (C) archaeal 16S rRNA libraries.
Data
Biodiversity indices [Chao1, Simpson's reciprocal (Simpson R), and evenness] of fungal assemblages based on the operational taxonomic units (OTUs) of internal transcribed spacer (ITS) fragments. The figure shows the comparisons between crops (left) and canola treatments (right). The canola treatments were canola grown as recommended (Can_RE), canol...
Data
Soil properties at each location.
Data
Significance of the relationships between the bacterial and fungal core/eco microbiomes, as determined by co-inertia analysis.
Data
Comparison of the bacterial core microbiome of canola from this study with bacterial taxa considered important in other studies.
Data
Maximum likelihood phylogenetic tree based on 175 bases of the archaeal 16S ribosomal RNA (rRNA) fragments. The branch length is proportional to the number of substitutions per site.
Data
Co-inertia analysis showing the relationship between bacterial and fungal core and eco microbiomes in (A) the rhizosphere of pea and (B) the roots of wheat. For each crop, the top graph is the projection of both bacterial and fungal operational taxonomic units (OTUs) onto the co-inertia plane. The cumulative projective inertias for the first two ax...
Data
Agronomic variables of (A) canola emergence counts, (B) post-spray weed count, and (C) canola yield. The canola treatments were canola grown as recommended (Can_RE), canola fertilized at 150% of the recommended rate (Can_HF), and canola seeded at 150% of the recommended rate (Can_HD).