HydroQual Laboratories Ltd

Calgary, Canada

HydroQual Laboratories Ltd

Calgary, Canada
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Harding M.W.,Innovotech Inc. | Olson M.E.,Innovotech Inc. | Howard R.J.,Alberta Agriculture and Rural Development | Marques L.L.R.,HydroQual Laboratories Ltd.
Acta Horticulturae | Year: 2011

Biofilms are communities of microorganisms growing within a self-produced extracellular polymeric matrix, and in association with a surface. Cells within a biofilm frequently have measurable, or observable, phenotypes that are distinct from comparable cells growing in more solitary or free-floating (planktonic) conditions. For example, cells within a biofilm are frequently able to survive antibiotic or biocide treatments that are lethal to comparable planktonic cells. Descriptions of biofilms formed by phytopathogenic bacteria and fungi have confirmed that, in some cases, plant disease management strategies may need to be effective against biofilms. Development of high through-put technologies, such as the MBEC" and BEST" plate assays for rapid culturing and assessment of microbial biofilms, have greatly accelerated the ability to screen for anti-biofilm compounds and treatments. Furthermore, use of these assays has facilitated characterizations of cell populations and growth stages within biofilm development for single and mixed species biofilms. Technology and information developed through this type of biofilm research has significant potential to support the identification and development of novel, effective biocontrol strategies. American Society for Testing Materials. 2010. WK25570 - New Test Method for Testing Disinfectant Efficacy against Pseudomonas aeruginosa Biofilm using the MBEC P&G Assay.


Harding M.W.,Alberta Agriculture and Rural Development | Daniels G.D.,Alberta Agriculture and Rural Development | Howard R.J.,Alberta Agriculture and Rural Development | Marques L.L.R.,HydroQual Laboratories Ltd. | And 3 more authors.
Acta Horticulturae | Year: 2014

For many pathogenic microbes, biofilm formation is a critical component of the disease cycle and is required for pathogenicity or full virulence. Recent innovation in in vitro biofilm reactors has allowed high throughput evaluation and testing of chemical treatments against microbial biofilms. For example, the BESTTM Assay is a versatile and specialized biofilm reactor capable of culturing bacterial and fungal biofilms in a replicated, high throughput, multi-well format. The microorganism forms a biofilm on the surfaces of pegs extending into liquid media contained within the microtitre plate wells. Additionally, planktonic cells also grow within the media in each well which allows simultaneous growth of biofilms and planktonic cultures within the wells of each reactor. Comparisons and evaluations of microbial biofilms on different surface materials can also be performed. For example, the bacterial ring rot pathogen Clavibacter michiganensis subsp. sepedonicus was studied in the BESTTM Assay to determine the conditions that promote growth in the biofilm form, the sensitivities of biofilm and planktonic cells to biocides, and the effects of biocide concentrations, exposure times and substrate types on efficacy. Technologies such as the BESTTM Assay excel at efficacy testing of chemical and biological agents being screened or developed for control of plant diseases, including postharvest diseases. Plant pathology research, phenotype screening, evaluating and formulating biological control products and protocols often ignore the critical aspect of biofilm potential. As a result, biofilm biology remains uncharacterized or unconfirmed for many plant-pathogen interactions and for most biocontrol agents. Biofilm reactors, such as the BESTTM Assay, provide technology for characterizing and evaluating these important issues.


Golby S.,University of Calgary | Ceri H.,University of Calgary | Gieg L.M.,University of Calgary | Chatterjee I.,University of Calgary | And 2 more authors.
FEMS Microbiology Ecology | Year: 2012

Bitumen extraction from the oil sands of Alberta has resulted in millions of cubic meters of waste stored on-site in tailings ponds. Unique microbial ecology is expected in these ponds, which may be key to their bioremediation potential. We considered that direct culturing of microbes from a tailings sample as biofilms could lead to the recovery of microbial communities that provide good representation of the ecology of the tailings. Culturing of mixed species biofilms in vitro using the Calgary Biofilm Device (CBD) under aerobic, microaerobic, and anaerobic growth conditions was successful both with and without the addition of various growth nutrients. Denaturant gradient gel electrophoresis and 16S rRNA gene pyrotag sequencing revealed that unique mixed biofilm communities were recovered under each incubation condition, with the dominant species belonging to Pseudomonas, Thauera, Hydrogenophaga, Rhodoferax, and Acidovorax. This work used an approach that allowed organisms to grow as a biofilm directly from a sample collected of their environment, and the biofilms cultivated in vitro were representative of the endogenous environmental community. For the first time, representative environmental mixed species biofilms have been isolated and grown under laboratory conditions from an oil sands tailings pond environment and a description of their composition is provided. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved 79 1 January 2012 10.1111/j.1574-6941.2011.01212.x Research Article Research Articles © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.


Golby S.,University of Calgary | Ceri H.,University of Calgary | Marques L.L.R.,HydroQual Laboratories Ltd. | Turner R.J.,University of Calgary
Microbial Ecology | Year: 2014

Here, we used an in vitro biofilm approach to study metal resistance and/or tolerance of mixed-species biofilms grown from an oil sand tailings pond in northern Alberta, Canada. Metals can be inhibitory to microbial hydrocarbon degradation. If microorganisms are exposed to metal concentrations above their resistance levels, metabolic activities and hydrocarbon degradation can be slowed significantly, if not inhibited completely. For this reason, bioremediation strategies may be most effective if metal-resistant microorganisms are used. Viability was measured after exposure to a range of concentrations of ions of Cu, Ag, Pb, Ni, Zn, V, Cr, and Sr. Mixed-species biofilms were found to be extremely metal resistant; up to 20 mg/L of Pb, 16 mg/L of Zn, 1,000 mg/L of Sr, and 3.2 mg/L of Ni. Metal mineralization was observed by visualization with scanning electron microscopy with metal crystals of Cu, Ag, Pb, and Sr exuding from the biofilms. Following metal exposure, the mixed-species biofilms were analyzed by molecular methods and were found to maintain high levels of species complexity. A single species isolated from the community (Rhodococcus erythropolis) was used as a comparison against the mixed-community biofilm and was seen to be much less tolerant to metal stress than the community and did not biomineralize the metals. © 2013 Springer Science+Business Media New York.


Tannenbaum L.V.,U.S. Army | Oosterbroek L.N.,HydroQual Laboratories Ltd. | Caro-Riano H.,HydroQual Laboratories Ltd.
Human and Ecological Risk Assessment | Year: 2015

ABSTRACT: With contaminated terrestrial sites always being multiple decades old before they first submit to health risk assessments for humans and ecological receptors, there is great opportunity for soils to elicit markedly lesser chemical toxicity than would be expected. Soil aging and weathering foster various physico-chemical processes that reduce the toxic potency or bioavailability of sequestered chemicals. Because only brand new and unadulterated chemicals with seemingly maximum potencies are used in animal dosing that supports toxicity factor derivation, measured chemical concentrations in soil can be misleading, producing exaggerated risk and hazard outcomes. We sought to determine the extent to which toxicity reduction occurs in experimentally amended soils, working with large soil volumes exposed to the unimpeded ambient condition for a calendar year. A broad toxicity testing matrix for two chemicals (i.e., multiple test species, endpoints, effect level concentrations, and soil types), found species’ responses in contaminated soils to be indistinguishable from those in control soil 80% and 98% of the time for the inorganic and organic compounds used, respectively; a case in point was lead with a soil concentration of 11,000 mg/kg. The results suggest that incorporating a toxicity reduction term is an indispensable task when deriving toxicity factors. © 2015, Copyright © Taylor & Francis Group, LLC.

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