The Industrial Biotech Section Seminars are a series of monthly lectures from internal researchers covering all aspects of research related to industrial biotechnology.
For more information, contact Thea Jess Plesner, tjp@bce.au.dk
Speaker: Associate Professor David Bernick from University of California Santa Cruz
Title:
"Engineering the future with Synthetic Bio"
Place: Auditorium 1170-347, Ole Worms Allé 3 , 8000 Aarhus C
David Bernick is an Associate Teaching Professor of Biomolecular Engineering at the University of California Santa Cruz campus, USA. Across both his teaching and research, he explores topics in synthetic biology and bioinformatics, emphasizing opportunities to aid under-resourced communities and the technical challenges in support of those communities. Over the past decade, he has had the pleasure of mentoring undergraduate students in the IGEM program (International Genetically Engineered Machines). Together, they have taken on projects in biofuel development, diabetes management, food insecurity, biotoxicity of water, agricultural plastic waste and access to contraceptives. Each of these areas share the larger goal of supporting our planet while normalizing sustained access to a flourishing life experience.
Dr. Bernick will discuss recently published (view paper) work to produce Exendin-4 with a consumable microbial chassis to improve access to this GLP-1 agonist. This peptide hormone and its derivatives are useful tools in the management of some forms of diabetes caused by insulin regulatory deficiency (link to paper). He will also discuss the IGEM program as a focus for undergraduate education for those interested in bioengineering, bioinformatics and other translational professions.
David Bernick
Associate Teaching Professor
Biomolecular Engineering
University of California
Santa Cruz, Ca
dbernick@ucsc.edu
Speakers: Bekir Engin Eser & Frederik Vig Benfeldt
Titles:
"Expanding the Toolbox of Fatty Acid Hydratases: A Thermostable Hydratase from Marinitoga piezophila with a Low Temperature Optimum and Unique Regioselectivity"
"Multi-enzyme/whole cell catalytic production of short-medium chain diols and diacids"
Place: Gustav Wieds Vej 10C, 8000 Aarhus C, Building 3130, Room 303.
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1st Speaker : Bekir Engin Eser
Title: Expanding the Toolbox of Fatty Acid Hydratases: A Thermostable Hydratase from Marinitoga piezophila with a Low Temperature Optimum and a Unique Regioselectivity
Abstract: Fatty Acid Hydratases (FAHs) catalyze the addition of water to unsaturated fatty acids to generate hydroxy fatty acids (HFAs) as products. Since HFAs have diverse application areas from materials and cosmetics industries and possess beneficial bioactivities, their benign enzymatic synthesis from abundant oils has attracted a lot of attention in the recent decade. One common challenge with biocatalytic conversions, including FAHs, is the stability of enzymes towards process conditions. Thus, we looked at Nature to find thermostable FAHs and characterized FAH ortholog from the thermostable and piezophilic organism Marinitoga piezophile. As expected, MpFAHY showed high thermostability, retaining over 90 % of its activity even after 30-min incubation at 70 °C. However, interestingly, the enzyme showed the highest activity at a much lower assay temperature of 20 °C, with sharp decreases above and below this temperature. This might indicate a physiological function of the enzyme, e.g. being part of a cold adaptation mechanism of the organism, which normally lives at 45-70 °C. Moreover, the purified enzyme requires NaCl to be active, consistent with the living habitat of its source organism. Another interesting property of the enzyme was its unique regioselectivity. MpFAHY was able to produce a mixture of 10-OH and 13-OH products from linoleic acid, with 13-OH being the preferred product, which is not a common property of wild-type FAHs.
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2nd Speaker: Frederik Vig Benfeldt
Title: Multi-enzyme/whole cell catalytic production of short-medium chain diols and diacids
Abstract: The rising issue of plastic pollution and the limited motivation for mechanical recycling urges the academia and industry to develop the technologies that enable close- or open- loop recycling and upcycling. To address this, the ACTPAC project seeks to develop a practical method to transform chemically inert C-C backboned plastic waste, specifically polyethylene (PE), into high-value monomers and biochemicals.One of the pivotal challenges in this transformation is the biotransformation of alkanes into α,ω-alkandiols and diacids, particularly due to the difficulty in directing C-H oxy-functionalization at the least reactive terminal positions. The ACTPAC project aims to utilize the unique capabilities of Cytochrome P450 (CYP450) enzymes to overcome this challenge. Our strategy involves screening and characterization of promising CYP153A orthologs capable of hydroxylating and oxidizing medium length alkanes into α, ω-diols and diacids. Engineering of selected CYP153A enzymes to fine-tune their specificity and activity towards targeted substrates through computational methods and machine learning algorithms. Lastly, scale-up is aimed to be conducted in large-scale bioreactors, with a focus on enhancing efficiency, cofactor regeneration, and fine-tuning reaction conditions to maximize yields.
Speakers: Laura Munoz, Susmit Chakraborty & Timothé Philippon
Title: Relevance of H2 consumption characteristics for acetogenic and methanogenic bioelectrochemical CO2 reduction
Place: Gustav Wieds Vej 10C, 8000 Aarhus C, Building 3130, Room 303.
Acetogens and methanogens reduce carbon dioxide with H2 as electron donor to obtain energy. This autotrophic metabolism is of interest for CO2 valorization biotechnologies, such as gas fermentation and even more microbial electrosynthesis. Indeed, the ability of those microbes to rapidly consume H2 could enhance electrochemical H2 production, once put near an electrode performing proton reduction. This hypothesis could be important for bio-electrochemical applications if proven to be true. To test our hypothesis, we must first characterize differences in H2 consumption characteristics between available acetogenic and methanogenic strains. Understanding those differences will also aid optimal strain selection for microbial electrosynthesis.
First, we determined the H2 threshold, i.e. the H2 partial pressure at which acetogenesis or methanogenesis halts, for diverse acetogenic (1) and methanogenic strains and observed strong differences. The observed H2 thresholds suggest significant variations in bioenergetics, potentially influencing growth yields and kinetics as well.
Furthermore, we determined the H2 consumption kinetics of different acetogens over a wide range of H2 initial concentrations. Interestingly, we observed that their H2 consumption followed first-order kinetics at under-saturated H2 levels. Our results thus suggest that acetogenic conversion rates can be increased by increasing the H2 partial pressures. In addition, we found strong differences in the first-order H2 consumption coefficient. We hypothesize the kinetic differences can be in part related to different types of hydrogenases of the strains.
In addition, to predict the performance of these strains in bioelectrochemical reactors, we incorporated the H2 threshold and kinetic data into mathematical models. These models simulate the behaviour of the strains under various conditions, such as electric current input, providing useful insights to optimize H2 utilization rates and enhance process efficiency.
Overall, our comprehensive new understanding of H2 dynamics for these hydrogenotrophic strains will guide the selection of suitable biocatalysts for microbial electrosynthesis.
References
1 Munoz, L; Philips, J. No acetogen is equal: Strongly different H2 thresholds reflect diverse bioenergetics in acetogenic bacteria. Environ Microbiol 2023;25:2032–40.
Lecture by: Professor Dr.-Ing. habil. Selin Kara, Department of Biological and Chemical Engineering, Aarhus University, Denmark
Title: "Process intensification for enzymatic decarboxylations: Transitioning from lab to industrial scales”
Place: Gustav Wieds Vej 10C, 8000 Aarhus C, Building 3130, Room 303
The application of nature’s catalysts, “enzymes,” for the synthesis of chemicals is a crucial emerging field of industrial biotechnology to meet the current and future needs of our society for sustainable manufacturing of chemicals. Nature uses an elegant and efficient synthetic strategy: Coupling enzymes in multi-step pathways without intermediate isolation and purification steps with precise spatial control of catalysis. Inspired by nature, the design of multi-step biotransformations has been attracting significant attention within the biocatalysis community. The talk will introduce enzymatic decarboxylation reactions (in cascading systems), exploring the use of non-conventional media, enzyme immobilization, and different operational modes for enhancing the volumetric productivity of these biocatalytic applications.
Lecture by: Maria Florencia Bambace & Herald Wilson Ambrose
Title: "Reuterin-based biological treatment to mitigate methane emissions from pig slurry storage”
Place: Gustav Wieds Vej 10C, 8000 Aarhus C, Building 3130, Room 303.
Methane (CH4) accounts for more than 90% of farmgate greenhouse gas (GHG) emissions in pig farming, with 80% being produced during manure management. In intensive pig production, slurry is stored in manure pits under the barn floor for short term storage (1 to 6 weeks) and in outside storage tanks for longer storage periods. During this time, CH4 is emitted as a result of microbial degradation of organic substrates present in the pig feces, combined with the anaerobic conditions developed under the slurry surface, which promote the activity of methanogens. Acidification is considered a benchmark technology for mitigating CH4 emissions from stored slurry. However, there are several associated drawbacks such as safety issues in application, soil sensitivity to increased sulphur loads during land application, and inhibitory effects on biogas production. Other chemical additives raise further environmental concerns; hence the need for a biological alternative is highly sought for CH4 mitigation in slurry storage.
Biological treatments studied thus far, utilizing microbial or enzymatic additives have shown little to insignificant potential for CH4 mitigation in pig and cattle slurry storages. In this seminar talk, we will present and discuss the results of a successful biological treatment aimed at inhibiting methanogenic activity in slurry storages, conducted on a laboratory scale headspace emission setup. The biological additive involves the use of Limosilactobacillus reuteri, which in the presence of glycerol produces reuterin, a broad-spectrum antimicrobial agent. We assessed the impact of endogenously produced reuterin on CH4 emissions from pig slurry by initially introducing both L. reuteri and glycerol into the slurry, which was then stored for a period of 26 to 30 days, during which CH4 emissions were measured. We also optimized the dosage combination of L. reuteri and glycerol. Our results showed that endogenously produced reuterin reduced CH4 emissions by 74-90% compared to untreated slurry. The environmental and biological aspect of our study will be further discussed, highlighting this novel approach as a promising alternative to H2SO4 or chemical surfactant treatments for reducing methanogenic activity in pig slurry storages.
Lecture by: Nele Van Dessel, CEO from Ernest Pharmaceuticals (USA)
Title: "The use of Salmonella bacteria to treat cancer”
Place: Zoom, https://aarhusuniversity.zoom.us/j/62375855091
The microbial biotechnology course will host an online guest lecture on the use of Salmonella bacteria to treat cancer.
The guest speaker is Nele Van Dessel, CEO from Ernest Pharmaceuticals (USA), a small startup company, trying to bring this new and intriguing microbial biotechnology to the market.
