I am a truly applied microbiologist (40 years spent into the laboratory) who loves to develop all kinds of bioprocesses, from lab to industrial scale, as well as I like very much to do on-site demonstrations of the NRC's straw/fiber processing line that I have used to produce technical grade flax and hemp fibers for biocomposites and textile applications. Recently, I joined a group of researchers dedicated to the conception (design) of eco-friendly materials. I am the one who run composting trials using a unique lab facility.
The degradation of toxic aromatic compounds, such as benzene, toluene and xylenes (BTX) in gaseou... more The degradation of toxic aromatic compounds, such as benzene, toluene and xylenes (BTX) in gaseous effluents was studied in a modular biofilter. The reactor was made of two columns separated by a grid. Each column was filled with a mixture of a commercial composted chicken manure and peat moss blend. The effluent gas was prehumidified and the temperature of the bed was maintained around 23{degrees}C. The biofilter was operated at a superficial gas velocity ranging from 10 to 100 m{sup 3}m{sup -2}h{sup 1} and at BTX organic load up to 90 g m{sup -3}h{sup -1}. Special attention was paid to the influence of the superficial gas velocity and the organic load on the filter bed`s elimination capacity. The bed hydrodynamic was also studied in order to determine the gas phase dispersion parameter. The performance and operational criteria of the biofilter were analyzed on the basis of water activity and water content. Respiration (i.e. CO{sub 2} production and O{sub 2} consumption) of the filter bed throughout a biofiltration experiment was followed using a radio-respirometric test and a respirometer.
The uptake of carbohydrate and nitrate by Catharanthus roseus cell suspension cultures was studie... more The uptake of carbohydrate and nitrate by Catharanthus roseus cell suspension cultures was studied in relation to biomass production in shake flasks. Biomass production was similar when using either 6, 12, 18, or 24 mM nitrate as the nitrogen source and 20 g L−1 sucrose as the carbon source. In all cases, maximum biomass production was reached when carbohydrates were entirely consumer by the cells. Apparent biomass yields, YX/S and YX/N were 0.49 g biomass g−1 glucose equivalent and 0.23 g biomass mmol−1 nitrate, respectively. The determination of the cellular carbon‐to‐nitrogen ration (C/N ration) resulted in the identification of three district growth phases: an active growth phase, and accumulation phase, and a biomass decline phase (endogenous metabolism). The onset of the last two phases was correlated with nitrate and sugar of the last two phases was correlated with nitrate and sugar exhaustion, respectively. Balanced stoichiometric equations describing the active growth and accumulation phases were proposed based on elemental composition and ash content of the biomass. The stoichiometric equation related to the accumulation phase predicts that the available sugars are stored as starch‐ and lipid‐like materials.
The effect of a nonionic surfactant (Tween 80) on 2,4,6-trinitrotoluene (TNT) mineralization by t... more The effect of a nonionic surfactant (Tween 80) on 2,4,6-trinitrotoluene (TNT) mineralization by the white-rot fungus Phanerochaete chrysosporium strain BKM-F-1767, was investigated in a liquid culture at 20, 50, and 100 mg TNT·L-1. The presence of 1% (w/v) Tween 80, at 20 mg·L-1 TNT, added to a 4-d-old culture, allowed the highest TNT mineralization level, that is 29.3% after 24 d, which is two times more than the control culture, without Tween 80 (13.9%). The mineralization of TNT resumed upon additional Tween 80 supplementation, consequently, 39.0% of the TNT was respired on day 68. Orbital agitation of the fungal culture was found detrimental to TNT mineralization, with or without Tween 80 in the culture medium. The surfactant also stimulated the growth of P. chrysosporium without any notable effect on either the glycerol consumption rate or the extracellular LiP and MnP activity levels. Respirometric assays highlighted some differences between the oxygen uptake rate of the fungal culture supplemented with or without Tween 80. Key words: 2,4,6-trinitrotoluene, TNT, surfactant, white-rot fungus, Phanerochaete chrysosporium, lignin peroxidase, manganese peroxidase.
A biological system to treat volatile hydrocarbon-contaminated gases generated during in situ bio... more A biological system to treat volatile hydrocarbon-contaminated gases generated during in situ bioventing and air sparging of subsurfaces contaminated with gasoline was field-tested. The system consisted of an air/water separator, a trickling filter, and a biofilter in series. During the field test, extensive monitoring was carried out to evaluate system performance, including the measurement of physical, chemical, biochemical, and microbiological parameters. Degradation and mineralization of volatile hydrocarbons such as benzene and toluene were demonstrated by gene probing and mineralization assays. Data collected showed an average removal of 90% of the BTX (benzene, toluene, and xylenes) and 72% for total hydrocarbons.
Abstract Pre-soaked flax stems were subjected to microwave assisted retting at different power le... more Abstract Pre-soaked flax stems were subjected to microwave assisted retting at different power levels and the effectiveness of microwave assisted retting was studied through the analysis of chemical compounds presented in the retted flax fibers processed from the stems. Response surface statistical design was used for this study with JMP® 10 software. Chemical analyses were performed by gravimetric methods to find out percentage of compounds. Cellulose, hemicellulose, lignin and pectin concentrations and the sugar content in the solution obtained after the treatment were subjected to analysis. Cellulose percentage in the fiber was increased significantly (p
... METHODS Jianzhong Yang, Marie-Josée Lorrain, Denis Rho, and Peter CK Lau ... 14. Scarff M, A... more ... METHODS Jianzhong Yang, Marie-Josée Lorrain, Denis Rho, and Peter CK Lau ... 14. Scarff M, Arnold S, Harvey L, and McNeil B. Near-infrared spectroscopy for bio-process monitoring and control: Current status and future trends. Crit Rev Biotechnol 26, 17-39 (2006). 15. ...
Applied Microbiology and Biotechnology, Nov 1, 1994
The biodegradation of the herbicide 2,4-di-chlorophenoxyacetic acid (2,4-D) by Pseudomonas cepaci... more The biodegradation of the herbicide 2,4-di-chlorophenoxyacetic acid (2,4-D) by Pseudomonas cepacia was assessed by microcalorimetry in a liquid medium and in sterilized soil at 25°C under aerobic conditions. It was found that thermograms of the rate of heat evolved versus time ( dQ/ dt versus t) can be used as a diagnostic tool to identify the time t 1 required
Applied Microbiology and Biotechnology, Feb 1, 1992
Sanguinaria canadensis L. plants were harvested from a local forest and calli were initiated from... more Sanguinaria canadensis L. plants were harvested from a local forest and calli were initiated from leaf explants. The production of benzophenanthridine alkaloids (i.e. sanguinarine, sanguilutine, sanguirubine, chelerythrine, chelilutine and chelirubine) by S. canadensis cell grown in modified B5 and IM2 media was compared to the alkaloid content of rhizomes. Sanguinarine accounted for approximately 80% of the total alkaloid content of cultured cells (1.3%, g g-1) while sanguinarine and sanguirubine accounted for 70% of rhizome alkaloids (9.0%, g g-1). Sanguinarine, chelirubine and chelerythrine were the only known alkaloids detected in cultured S. canadensis cells. Maximum alkaloid production of cultures performed using B5 medium, containing half the original nitrate concentration, was observed following extracellular nitrate and sugar depletion. The scale-up of this culture was successfully performed in a 2-1 immobilization bioreactor. The consumption of sugar and nitrate as well as the oxygen (OTR) and carbon dioxide (CTR) transfer rates of the immobilized cell culture were monitored for 15 days. The maximum sugar and nitrate consumption rates were 1.8 g l-1 per day and 2.3 mM per day respectively. The maximum OTR and CTR of the immobilized cell culture were 0.8 mmol O2 l-1 h-1 and 0.95 mmol CO2 l-1 h-1 respectively. The sanguinarine yield of this culture reached 1.0% based on biomass dry weight (g g-1 dw) by day 15.
The degradation of toxic aromatic compounds, such as benzene, toluene and xylenes (BTX) in gaseou... more The degradation of toxic aromatic compounds, such as benzene, toluene and xylenes (BTX) in gaseous effluents was studied in a modular biofilter. The reactor was made of two columns separated by a grid. Each column was filled with a mixture of a commercial composted chicken manure and peat moss blend. The effluent gas was prehumidified and the temperature of the bed was maintained around 23{degrees}C. The biofilter was operated at a superficial gas velocity ranging from 10 to 100 m{sup 3}m{sup -2}h{sup 1} and at BTX organic load up to 90 g m{sup -3}h{sup -1}. Special attention was paid to the influence of the superficial gas velocity and the organic load on the filter bed`s elimination capacity. The bed hydrodynamic was also studied in order to determine the gas phase dispersion parameter. The performance and operational criteria of the biofilter were analyzed on the basis of water activity and water content. Respiration (i.e. CO{sub 2} production and O{sub 2} consumption) of the filter bed throughout a biofiltration experiment was followed using a radio-respirometric test and a respirometer.
The uptake of carbohydrate and nitrate by Catharanthus roseus cell suspension cultures was studie... more The uptake of carbohydrate and nitrate by Catharanthus roseus cell suspension cultures was studied in relation to biomass production in shake flasks. Biomass production was similar when using either 6, 12, 18, or 24 mM nitrate as the nitrogen source and 20 g L−1 sucrose as the carbon source. In all cases, maximum biomass production was reached when carbohydrates were entirely consumer by the cells. Apparent biomass yields, YX/S and YX/N were 0.49 g biomass g−1 glucose equivalent and 0.23 g biomass mmol−1 nitrate, respectively. The determination of the cellular carbon‐to‐nitrogen ration (C/N ration) resulted in the identification of three district growth phases: an active growth phase, and accumulation phase, and a biomass decline phase (endogenous metabolism). The onset of the last two phases was correlated with nitrate and sugar of the last two phases was correlated with nitrate and sugar exhaustion, respectively. Balanced stoichiometric equations describing the active growth and accumulation phases were proposed based on elemental composition and ash content of the biomass. The stoichiometric equation related to the accumulation phase predicts that the available sugars are stored as starch‐ and lipid‐like materials.
The effect of a nonionic surfactant (Tween 80) on 2,4,6-trinitrotoluene (TNT) mineralization by t... more The effect of a nonionic surfactant (Tween 80) on 2,4,6-trinitrotoluene (TNT) mineralization by the white-rot fungus Phanerochaete chrysosporium strain BKM-F-1767, was investigated in a liquid culture at 20, 50, and 100 mg TNT·L-1. The presence of 1% (w/v) Tween 80, at 20 mg·L-1 TNT, added to a 4-d-old culture, allowed the highest TNT mineralization level, that is 29.3% after 24 d, which is two times more than the control culture, without Tween 80 (13.9%). The mineralization of TNT resumed upon additional Tween 80 supplementation, consequently, 39.0% of the TNT was respired on day 68. Orbital agitation of the fungal culture was found detrimental to TNT mineralization, with or without Tween 80 in the culture medium. The surfactant also stimulated the growth of P. chrysosporium without any notable effect on either the glycerol consumption rate or the extracellular LiP and MnP activity levels. Respirometric assays highlighted some differences between the oxygen uptake rate of the fungal culture supplemented with or without Tween 80. Key words: 2,4,6-trinitrotoluene, TNT, surfactant, white-rot fungus, Phanerochaete chrysosporium, lignin peroxidase, manganese peroxidase.
A biological system to treat volatile hydrocarbon-contaminated gases generated during in situ bio... more A biological system to treat volatile hydrocarbon-contaminated gases generated during in situ bioventing and air sparging of subsurfaces contaminated with gasoline was field-tested. The system consisted of an air/water separator, a trickling filter, and a biofilter in series. During the field test, extensive monitoring was carried out to evaluate system performance, including the measurement of physical, chemical, biochemical, and microbiological parameters. Degradation and mineralization of volatile hydrocarbons such as benzene and toluene were demonstrated by gene probing and mineralization assays. Data collected showed an average removal of 90% of the BTX (benzene, toluene, and xylenes) and 72% for total hydrocarbons.
Abstract Pre-soaked flax stems were subjected to microwave assisted retting at different power le... more Abstract Pre-soaked flax stems were subjected to microwave assisted retting at different power levels and the effectiveness of microwave assisted retting was studied through the analysis of chemical compounds presented in the retted flax fibers processed from the stems. Response surface statistical design was used for this study with JMP® 10 software. Chemical analyses were performed by gravimetric methods to find out percentage of compounds. Cellulose, hemicellulose, lignin and pectin concentrations and the sugar content in the solution obtained after the treatment were subjected to analysis. Cellulose percentage in the fiber was increased significantly (p
... METHODS Jianzhong Yang, Marie-Josée Lorrain, Denis Rho, and Peter CK Lau ... 14. Scarff M, A... more ... METHODS Jianzhong Yang, Marie-Josée Lorrain, Denis Rho, and Peter CK Lau ... 14. Scarff M, Arnold S, Harvey L, and McNeil B. Near-infrared spectroscopy for bio-process monitoring and control: Current status and future trends. Crit Rev Biotechnol 26, 17-39 (2006). 15. ...
Applied Microbiology and Biotechnology, Nov 1, 1994
The biodegradation of the herbicide 2,4-di-chlorophenoxyacetic acid (2,4-D) by Pseudomonas cepaci... more The biodegradation of the herbicide 2,4-di-chlorophenoxyacetic acid (2,4-D) by Pseudomonas cepacia was assessed by microcalorimetry in a liquid medium and in sterilized soil at 25°C under aerobic conditions. It was found that thermograms of the rate of heat evolved versus time ( dQ/ dt versus t) can be used as a diagnostic tool to identify the time t 1 required
Applied Microbiology and Biotechnology, Feb 1, 1992
Sanguinaria canadensis L. plants were harvested from a local forest and calli were initiated from... more Sanguinaria canadensis L. plants were harvested from a local forest and calli were initiated from leaf explants. The production of benzophenanthridine alkaloids (i.e. sanguinarine, sanguilutine, sanguirubine, chelerythrine, chelilutine and chelirubine) by S. canadensis cell grown in modified B5 and IM2 media was compared to the alkaloid content of rhizomes. Sanguinarine accounted for approximately 80% of the total alkaloid content of cultured cells (1.3%, g g-1) while sanguinarine and sanguirubine accounted for 70% of rhizome alkaloids (9.0%, g g-1). Sanguinarine, chelirubine and chelerythrine were the only known alkaloids detected in cultured S. canadensis cells. Maximum alkaloid production of cultures performed using B5 medium, containing half the original nitrate concentration, was observed following extracellular nitrate and sugar depletion. The scale-up of this culture was successfully performed in a 2-1 immobilization bioreactor. The consumption of sugar and nitrate as well as the oxygen (OTR) and carbon dioxide (CTR) transfer rates of the immobilized cell culture were monitored for 15 days. The maximum sugar and nitrate consumption rates were 1.8 g l-1 per day and 2.3 mM per day respectively. The maximum OTR and CTR of the immobilized cell culture were 0.8 mmol O2 l-1 h-1 and 0.95 mmol CO2 l-1 h-1 respectively. The sanguinarine yield of this culture reached 1.0% based on biomass dry weight (g g-1 dw) by day 15.
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