Department Calendar of Events

BioZone will be hosting Professor Amanda Wright, from the Department of Human Health and Nutritional Sciences, at the University of Guelph on Thursday, February 24th from 3 pm – 4:30 pm.

Abstract

Functional foods deliver health benefits beyond basic nutrition. Natural health product (NHP) is the Canadian regulatory term for over-the-counter supplements that contain health-promoting molecules derived from foods, e.g., vitamins, minerals, herbals, probiotics. Together, these product categories encompass so much of the science and technology surrounding foods and nutrition. Our group works at the food-nutrition interface to support the evidence-basis for a variety of functional foods and NHPs. We have specialized interests in dietary lipids and in understanding how the structure of foods and food ingredients influences bioavailability and metabolic response, mediated by events in the gastrointestinal tract.

For example, what role does triacylglycerol crystallinity play in determining postprandial lipemia and what does this mean for saturated fatty acids? This talk will discuss our application of in vitro digestion and human research methods to relate emulsion properties to gastric microstructure, emptying, and postprandial satiety and lipemia (a risk factor for cardiometabolic diseases) to highlight the benefits of integrated food-nutrition research. Examples drawing on other functional foods will also be presented. Foods have always been functional. Focusing specifically on food structure and applying a physical property lens to what happens in the gastrointestinal tract paves the way for better understanding the nuanced relationships between foods and health, and ultimately to realize the potential for efficacious functional foods and NHPs.

Bridging the gap between microbiology and chemistry in built environments

Prof. Sarah Haines, Assistant Professor
Department of Civil & Mineral Engineering
University of Toronto

We spend the majority of our time indoors where the built environment has important implications for human health, particularly for those with asthma. Asthma disproportionately impacts low-socioeconomic communities due to poor quality housing associated with mold and moisture exposure. One of the main exposures to mold in housing is through the resuspension of floor dust. Microbes grow in carpet dust at elevated relative humidity conditions and release microbial volatile organic compounds (mVOCs). However, we do not know how the influence of moisture may drive species composition and chemical emissions from microbes in dust and on common building materials. Understanding
these interactions in the indoor environment is the next frontier in environmental engineering and has the potential to lead to substantial improvements in public health.

Utilizing cutting edge techniques, my work has ranged from collecting dust in carpet from homes in Ohio to analyzing dust particles from the International Space Station. Ultimately, results from my work have demonstrated that microbial growth can be quantitatively modeled in buildings, and for the first time demonstrated interactions between chemicals and microbes in house dust under elevated relative humidity conditions. My future work will link climate change, social justice, and viruses to contribute to healthy indoor environments.

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External members were required to register to receive the link and passcode. Registration closed at 9am on March 7.

Desmond Moser, Western

Host: Prof. Jane Howe

The characterization of long-lived minerals, including natural metal deposits of copper, and their corrosion behaviours is an area of shared interest among geo- and materials scientists. This is particularly true in regard to transdisciplinary efforts to improve the design of multi-barrier Deep Geological Repositories for spent nuclear fuel. Examples of our application of micro- and nano-characterization techniques (e.g. EBSD, SIMS, Atom Probe Tomography) will be presented for a range of geomaterials including > 4 billion-year-old weakly-radioactive minerals in Martian meteorites and 1 billion-year-old copper from Earth.

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Professor Desmond Moser has spent most of his career unraveling the evolution of ancient planetary crusts using weakly radioactive and highly resilient microminerals. Increasingly his group is directing their expertise to help understand all aspects of the long-lived natural materials important to designing multi-barrier Deep Geological Repositories for spent nuclear fuel.

Prof. Moser conducts solid Earth and planetary science research using Western’s nationally unique Zircon and Accessory Phase Laboratory (ZAPLab). Micromineral crystal growth and deformation analysis (e.g. CL, EBSD) is integrated with field mapping, microchemical (EDS, WDS), petrologic and mass spectrometry measurements (radiogenic and stable isotopes) at Western and partner institutes. His active projects investigate meteorites, crustal cross-sections, kimberlite xenoliths, sedimentary basins and impact structures in the Americas, Africa and Europe. His ZAPLab team is advancing our knowledge of the timing and nature of processes that form and modify planetary crusts and ore deposits while advancing the growing sub-discipline of accessory mineral science.

View the complete 2021-22 LLE schedule

Questions? Please contact Delicia Ansalem, Communications Officer & External Relations Liaison delicia.ansalem@utoronto.ca

External members are required to register to receive the link and passcode. Registration closed at 9am on March 21.

Co-hosted with the Institute for Water Innovation (IWI)

Benny Freeman, University of Texas at Austin

Host: Prof. Jay Werber

Charged polymer membranes are widely used for water purification applications involving control of water and ion transport, such as reverse osmosis and electrodialysis.  Efforts are also underway worldwide to harness separation properties of such materials for energy generation in related applications such as reverse electrodialysis and pressure retarded osmosis.  Additional applications, such as energy recovery ventilation and capacitive deionization, rely on polymer membranes to control transport rates of water, ions, or both.  Improving membranes for such processes would benefit from more complete fundamental understanding of the relation between membrane structure and ion sorption, diffusion and transport properties in both cation and anion exchange membrane materials. Ion-exchange membranes often contain strongly acidic or basic functional groups that render the materials hydrophilic, but the presence of such charged groups also has a substantial impact on ion (and water) transport properties through the polymer.

We are exploring the influence of polymer backbone structure, charge density, and water content on ion transport properties.  Results from some of these studies will be presented, focusing on transport of salt, primarily NaCl, through various neutral, positively charged and negatively charged membranes via concentration gradient driven transport (i.e., ion permeability) and electric field driven transport (i.e., ionic conductivity).  One long-term goal is to develop and validate a common framework to interpret data from both electrically driven and concentration gradient driven mass transport in such polymers and to use it to establish structure/property relations leading to rational design of membranes with improved performance.

Ion sorption and permeability data were used to extract salt diffusion coefficients in charged membranes.  Concentrations of both counter-ions and co-ions in the polymers were measured via desorption followed by ion chromatography or flame atomic absorption spectroscopy.  Salt permeability, sorption and electrical conductivity data were combined to determine individual ion diffusion coefficients in neutral, cation exchange and anion exchange materials. Manning’s counter-ion condensation models and the Mackie/Meares model were used to correlate and, in some cases, predict the experimental data.
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Professor Benny Freeman is the William J. (Bill) Murray, Jr. Endowed Chair of Engineering in the Chemical Engineering department at The University of Texas at Austin.  He is a professor of Chemical Engineering and has been a faculty member for 30 years.  He completed graduate training in Chemical Engineering at the University of California, Berkeley, earning a Ph.D. in 1988.  In 1988 and 1989, he was a postdoctoral fellow at the Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI), Laboratoire Physico-Chimie Structurale et Macromoléculaire in Paris, France.  Dr. Freeman was a member of the chemical engineering faculty at NC State University from 1989 – 2002, and he has been a professor of chemical engineering at The University of Texas at Austin since 2002.  Dr. Freeman’s research is in polymer science and engineering and, more specifically, in mass transport of small molecules in solid polymers.  His research group focuses on structure/property correlation development for desalination and gas separation membrane materials, new materials for hydrogen separation, natural gas purification, carbon capture, and new materials for improving fouling resistance in liquid separation membranes. He leads the Center for Materials for Water and Energy Systems (M-WET), a DOE Energy Frontier Research Center and serves as Challenge Area Leader for Membranes in the National Alliance for Water Innovation (NAWI), a five-year, DOE sponsored Energy-Water Desalination Hub to address critical technical barriers needed to radically reduce the cost and energy of water purification.

His research is described in more than 450 publications and 30 patents/patent applications.  He has co-edited 5 books on these topics.  He has won a number of awards, including a Fulbright Distinguished Chair in Disruptive Separations (2017), Fellow of the North American Membrane Society (NAMS) (2017), the Distinguished Service Award from the Polymeric Materials: Science and Engineering (PMSE) Division of the American Chemical Society (ACS) (2015), Joe J. King Professional Engineering Achievement Award from The University of Texas (2013), American Institute of Chemical Engineers (AIChE) Clarence (Larry) G. Gerhold Award (2013), Society of Plastics Engineers International Award (2013), Roy W. Tess Award in Coatings from the PMSE Division of ACS (2012), the ACS Award in Applied Polymer Science (2009), AIChE Institute Award for Excellence in Industrial Gases Technology (2008), and the Strategic Environmental Research and Development Program Project of the Year (2001).  He is a Fellow of the AAAS, AIChE, ACS, and the PMSE and IECR Divisions of ACS.  He has served as chair of the PMSE Division of ACS, chair of the Gordon Research Conference on Membranes: Materials and Processes, President of the North American Membrane Society, Chair of the Membranes Area of the Separations Division of the AIChE, and Chair of the Separations Division of AIChE. His research has served as the basis for several startup companies, including Energy-X and NALA Systems.

View the complete 2021-22 LLE schedule

Questions? Please contact Delicia Ansalem, Communications Officer & External Relations Liaison delicia.ansalem@utoronto.ca

For more information about the series:
Contact Sofia Bonilla; sofia.bonillatobar@mail.utoronto.ca or Olan Raji; olan.raji@utoronto.ca

External members are required to register to receive the link and passcode. Registration closed at 9am on April 4.

Anne Meyer, Technical University of Denmark

Host: Prof. Emma Master

From the discovery of new enzymes for seaweed processing, over kinetic studies of plastic degrading enzymes, to engineering of glycoside hydrolases for synthesis of human milk oligosaccharides: The key point is always to understand how enzymes function in order to employ them in new processes. In this presentation I will give three examples of our recent work that relates to how new insight has led to potential new uses of enzymes and how the quest for using enzymes in new processes has led to new fundamental discoveries and/or new methods.

Example 1: Brown macroalgae is a source of particular fucose-rich polysaccharides, fucoidans, that possess a range of beneficial bioactivities such as anti-inflammatory and immune-modulatory effects. Enzymes that can selectively modify or catalyze depolymerization of fucoidans are a target of our research in order to deliver well-defined product structures that exert consistent and specific bioactivity properties. As part of this quest we have for example developed a way to stabilize fragile bacterial fucoidanases¹ and – by serendipity – discovered an unusual quaternary hexameric enzyme structure that seem to represent a novel protein thermostabilization mechanism². We also realized that a particular marine fungus, Paradendryphiella salina has adapted to thrive on brown macroalgae only by having alginate lyase encoding genes³.

Example 2: We have recently embarked on studying enzymes that can degrade plastic, notably polyethylene terephthalate (PET). During this work, we realized the critical significance of the degree of the PET crystallinity for the enzymatic rate, and realized, using scanning electron microscopy, that the PET surface looks very different after enzymatic attack dependent on the initial crystallinity of the PET substrate⁴.

Example 3: Lastly, I will like to share some protein engineering approaches we use – although not always equally successfully! – to try to get glycoside hydrolases to catalyze transglycosylation reactions. We are interested in transglycosylation technology as a way to design bioactive glycan structures, first and foremost human milk oligosaccharide mimics^5-7. In all cases, insight into how the enzymes work is a prerequisite for understanding their function in nature, and forms the foundation for developing enzyme-catalyzed processes and products for the future.

¹ doi: 10.3390/md16110422
² doi: 10.1038/s41598-021-98588-3
³ doi: 10.1038/s41598-019-48823-9
⁴ doi: 10.1016/j.nbt.2022.02.0065
⁵ doi: 10.3390/molecules24112033
⁶ doi: 10.1016/j.enzmictec.2018.04.008
⁷ doi: 10.3390/app112311493

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Anne S. Meyer is a Professor of Enzyme Technology at the Technical University of Denmark (DTU) and Head of the Protein Chemistry & Enzyme Technology Division in the Department of Biotechnology and Biomedicine (DTU Bioengineering), DTU. She is also a group leader for the Enzyme Technology group in the Division. Anne holds an MSc from the University of Copenhagen, an MSc from the University of Reading, UK (1987), and a PhD from DTU (1993). Employed at DTU since 1988 in various positions, Anne has also had two postdoc stays at The University of California, Davis. She became a Full Professor at DTU in 2006 and headed The Center for BioProcess Engineering at DTU until summer 2018, where she assumed her current role as Head of the Protein Chemistry & Enzyme Technology Division at DTU Bioengineering. She has been a visiting professor at The Department of Chemical and Biomolecular Engineering, University of Melbourne, Australia from 2017-2020.

View the complete 2021-22 LLE schedule

Questions? Please contact Delicia Ansalem, Communications Officer & External Relations Liaison delicia.ansalem@utoronto.ca

Join SOCAAR at their next seminar on Wednesday, April 6th from 3pm-4pm!

Observing global fine-scale changes in ambient NO2 during COVID-19 lockdowns using satellites

Matthew Cooper
Physical Science Officer
Environment and Climate Change Canada

Nitrogen dioxide (NO2) is an important contributor to air pollution with serious health
effects. Many reports have shown that NO2 concentrations decreased in 2020 during COVID19 lockdowns, but these studies are limited by the availability of air quality monitoring
globally. In this talk, I will show how we use satellite observations to infer global fine
resolution (~1km) ground-level NO2 concentrations. Using these observations, we find that
mean NO2 concentrations are ~30% lower in countries with strict COVID-19 lockdowns than
in those without. I will also present case studies that compare lockdown-driven changes to
long-term NO2 trends, and show how the sensitivity of NO2 to lockdowns varied across cities,
countries, and emissions sectors.

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External members are required to register to receive the link and passcode. Registration closed at 9am on April 11.

Co-hosted with the Institute for Water Innovation (IWI)

Nathalie Tufenkji, McGill

Host: Prof. Jay Werber

The degradation of bulk plastics in the environment leads to the release of microplastics that can contaminate water supplies, agricultural fields, and foods we consume. Weathering of a single microplastic particle can yield up to billions of nanoplastics and nanoplastic pollution is expected to be ubiquitous in the environment. Nanoplastics are potentially more hazardous than microplastics because they can cross biological membranes; yet, there is little data on the occurrence, fate and impacts of nanoplastics. A key challenge in understanding the environmental burden of nanoplastics is the detection of such small, carbon-based particles in complex natural matrices such as soils.

Environmental nanoplastics are often thought of as an extension of microplastics with a distinction based on an arbitrary size cut-off, typically 100 nm or 1000 nm. In our view, in terms of environmental implications and analytical challenges, a size cut-off distinction provides little guidance. While a consensus on the precise definition of “nanoplastic” has yet to be reached, we advocate for a characteristic-based distinction between nanoplastics and microplastics. Based on existing literature and analytical methods, we present a set of characteristics, distinct from microplastics and other contaminants, that define environmental nanoplastics.

This lecture will present an overview of our work aimed at overcoming challenges to better understand the fate and impacts of nanoplastics in terrestrial and aquatic environments. I will discuss new approaches for detection of nanoplastics in complex matrices and recent advances in our understanding of the toxicity of nanoplastics.

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Nathalie Tufenkji is a Professor in the Department of Chemical Engineering at McGill University where she holds the Tier I Canada Research Chair in Biocolloids and Surfaces. She works in the area of particle-surface interactions with applications in protection of water resources, plastic pollution as well as the discovery of natural antimicrobials. Professor Tufenkji was awarded the Killam Research Fellowship, the Engineers Canada Award for the Support of Women in the Engineering Profession, the Chemical Institute of Canada Environment Award, an Early Career Research Excellence Award by the Faculty of Engineering at McGill University, the YWCA Woman of Distinction Award in Science and Technology, and the Hatch Innovation Award of the Canadian Society for Chemical Engineers. She was elected to the College of New Scholars, Artists and Scientists of the Royal Society of Canada in 2016 and the Canadian Academy of Engineering in 2020. Beyond her research and teaching roles, Professor Tufenkji also serves as Associate Director of the Brace Center for Water Resources Management at McGill and has co-chaired several major international conferences. She has also served on the editorial advisory boards of the journals Environmental Science and Technology, npj Clean Water, Water Research, Colloids and Surfaces B, Advances in Colloid and Interface Science, and Environmental Science: Nano.

View the complete 2021-22 LLE schedule

Questions? Please contact Delicia Ansalem, Communications Officer & External Relations Liaison delicia.ansalem@utoronto.ca

SAVE THE DATE! The 5th ChemE Exhibition & 36th Dinner will be held at the Delta Chelsea Hotel located at 33 Gerrard St W. Invitations have been sent to faculty, staff, students, alumni, and industry partners. If you have questions regarding how to register, please email jennifer.hsu@utoronto.ca.