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Oral presentations during the 6th edition of the Student Symposium of CRIBIQ.
CNETE was well-represented at the 6th edition of the CRIBIQ Student Symposium on Quebec’s Bioeconomy: Challenges, Issues, and Solutions for a Sustainable Future.
Congratulations to Bintou Sangare, Mariana Valdez Castillo, and Carlos Neto for their outstanding oral presentations and scientific contributions.
In particular, we would like to applaud Carlos for the well-deserved award he received for his brilliant oral presentation.
Below, you can explore the topics of their research projects.
Dynamic Modeling of Peptide Immobilization on Metal Surfaces
S. Sangare· A. Wilkin · S. Barnabé · M. Valdez Castillo · B. Delgado Cano · A. Avalos Ramirez
The technological development of several industrial sectors relies heavily on critical and strategic minerals (CSMs). CSMs are non-renewable natural resources. Canada has the opportunity to become a key player in the development of new technologies due to the presence of deposits containing 60 CSMs considered essential for energy transition and the communications sector. CSMs have environmental impacts throughout their life cycle and must be handled responsibly to avoid affecting ecosystems and human health. For example, during their extraction, large volumes of water are consumed, and similar volumes of wastewater containing metals are generated. Managing wastewater containing CSMs is a challenge for businesses and municipalities. To preserve natural resources for future generations, it is necessary to develop sustainable operating methods that include water treatment and CSM recycling.
For the removal of dissolved or suspended minerals in water, several studies have been conducted. Cation adsorption or fine particle adsorption is a promising technology. It has the potential to recover CSMs for recycling in the production chain. Among the types of adsorption, biosorption has several advantages. For example, adsorption materials are bio-sourced, biodegradable, and often produced from residues, resulting in a low material cost. Peptides are biomolecules that can be used to recover CSMs due to their strong affinity with metal surfaces. To develop and optimize adsorption methods, a large number of experimental tests are necessary, consuming significant time and material resources.
Molecular modeling can be used to simulate the physicochemical phenomena that occur during the recovery of particles of critical and strategic minerals (CSMs) suspended in water, approximating the experience of water-peptide-metal interactions. Once the model is constructed and validated, an infinite number of operational conditions can be simulated with great precision and in a short time. Modeling the adsorption of peptides on metal surfaces thus reduces the number of experimental trials, serving as a tool to select the most promising systems and plan well-directed experimental trials. This study demonstrates the modeling of the adsorption of a three-amino acid peptide (glutathione, GSH) on platinum metal particles, aiming to create a biocomposite that could be easily recovered by flotation. This virtual model was created using Tinker 8 software. The simulation (6000 steps) was conducted under conditions of 298 K temperature and 1 atm pressure. Each simulation step had a duration of 2 femtoseconds, and a simulation of peptide-platinum adsorption could be established in just 12 nanoseconds. The simulation results show that the peptide adsorption follows a Langmuir isotherm. The developed model will be validated and used to optimize the conditions for GSH adsorption on platinum for bio-metallurgical applications.
Valorization of whey by one-step fermentation using a co-culture of yeasts to produce biomolecules with aroma and flavor properties.
M. Valdez Castillo · S. Kaur Brar · S. Arriaga · J-F. Blais · M. Heitz · A. Avalos Ramirez
Agriculture and food processing are key industrial sectors for the economy of Quebec and Canada. Indeed, Canada is among the top 10 cheese producers in the world. In 2022, 0.5 million tons of cheese were produced in Canada, with 28% of this production located in the province of Quebec. However, cheese production generates a liquid by-product called whey; 9 kg of whey is produced per kg of cheese. Consequently, in Canada, 4.8 million tons of whey were generated in 2022. Whey mainly contains lactose and proteins, contributing to a high chemical oxygen demand (COD). Current environmental regulations require proper disposal of whey to prevent soil and water pollution. Whey can be biotransformed by yeast into ethanol and biomolecules such as 2-phenylethanol (2PE) with aroma and flavor properties. 2PE is highly sought after in various industries (food, pharmaceutical, etc.) due to its organoleptic properties. 2PE is produced by yeast through the Ehrlich metabolic pathway, with L-phenylalanine (L-Phe) being used as the precursor for 2PE.
The present study aimed to valorize whey to produce 2PE by fermentation in the presence of 2 yeasts, Kluyveromyces marxianus and Debaryomyces hansenii. Acid whey was used as the carbon source, while the renewable nitrogen sources were hydrolyzed and non-hydrolyzed brewer’s yeast (LB).
The non-hydrolyzed LBs promoted the growth of both yeasts and the production of 2PE during flask fermentation. Fermentation was scaled up in a 2 L bioreactor to control pH and aeration, which improved 2PE production; the yield was 0.61 g2PE/gL-Phe; as for productivity (0.04 g2PE/L∙h), it turned out to be 2 times higher than those reported in the literature. In addition, the bioprocess generates a liquid effluent that requires no additional treatment, as its COD after fermentation is lower than environmental requirements. Thus, the bioprocess prevents environmental pollution and contributes to the circular economy of the dairy industry. In addition, an economic comparison was made between the use of a culture medium based on agro-industrial residues and a synthetic medium. The preliminary economic analysis was carried out considering fermentation in a 1000 L bioreactor; the price of raw materials and biobased 2PE were those associated with large quantities. The results of the analysis show that the use of a biosourced medium is economically profitable. An industrial scale-up would increase the profits and confirm that the valorization of residues has great potential in terms of sustainable development and economic relevance in rural areas.
Biopesticide potential of terpenic esters enzymatically synthesized by lipase B from Candida antarctica immobilized on magnetic cashew apple bagasse lignin.
C. Neto · B. Moerschbacher · A. Avalos Ramirez · M. Heitz · T. Rodrigues ·M. Rocha
The enzymatic biotransformation of terpenic alcohols enables the selective production of new compounds with improved bioactivity. However, only a few studies have been performed using enzymes, primarily immobilized on materials derived from natural sources. In this context, lipase B from Candida antarctica (CAL-B) was immobilized on lignin extracted from cashew apple bagasse (CAB) conjugated with magnetic nanoparticles to be used in the biotechnological synthesis of terpenic esters. Subsequently, the bioactive potential of the synthesized compounds was evaluated through in vitro and in vivo antimicrobial assays using Phaseolus vulgaris plants. The immobilization process took place predominantly by adsorption by interfacial activation followed by covalent bonds, and the enzymatic load of 5 mgPROTEIN/gSUPPORT was chosen, as it generated a biocatalyst (Lig-MNPs_CALB) with good catalytic activity (12.6 ± 0.7 U/g) and immobilization yield (71.5 ± 1.2%). Furthermore, Lig-MNPs_CALB showed excellent stability at 50 °C, maintaining 65% of its activity after 96 h of exposure, and it was more stable in heptane, retaining 49.3 ± 1.3% of its activity after 48 h. The biocatalyst obtained also showed good storage stability at 4 °C, with retention of 73% of its activity after 60 days. For the synthesis of citronellyl butyrate ester using free and immobilized CAL-B and synthetic alcohol as a substrate, the optimal esterification conditions were 50 °C, 1:1 molar ratio (alcohol:acid), 10 mgPROTEIN/mL and 200 RPM. The esterification yield was higher when catalyzed by the immobilized enzyme (Lig-MNPs_CALB), achieving 96.4 ± 2.1% compared to the yield obtained with free CAL-B (55 ± 3.9%) after 24 h of reaction. Thecatalytic activity of LigMag_CALB was maintained after 10 reactional cycles, with a citronellyl butyrate synthesis yield exceeding 95%, which makes this process promising to pectin industry. The essential oil extracted from the Cymbopogon winterianus plant was characterized and also evaluated as an alternative and low-cost source for the synthesis of terpenic esters. The major compounds present in the essential oil were citronellal, geraniol, citronellol, geranyl acetate and elemol, with emphasis on the geraniol and citronellol terpenic alcohols. Esterification reactions using LigMNPs_CALB resulted in yields above 96% for citronellyl butyrate and geranyl butyrate within 24 h of reaction, highlighting the potential of this raw material for this purpose. Additionally, the antimicrobial activity of citronellol and geraniol in its esterified form were improved, and the respective esters were also effective to reduce the incidence and severity of diseases in bean plants, which adds this valuable property to its industrial applications. Therefore, a more cost-effective approach with reduced environmental impact was developed to obtain new green products with added value.