Matching Items (14)
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- All Subjects: Metabolic Engineering
- All Subjects: Renewable Energy
- Creators: Chemical Engineering Program
- Member of: Barrett, The Honors College Thesis/Creative Project Collection
Description
Fossil fuels have been the primary source of energy in the world for many decades. However, they are among the top contributors of the greenhouse gas emissions in the atmosphere. The objective of this research was to produce a more environmentally friendly biofuel from Algae-Helix and Salicornia biomasses. Experiments were conducted using a hydrothermal liquefaction (HTL) technique in the HTL reactor to produce biofuel that can potentially replace fossil fuel usage. Hydrothermal Liquefaction is a method used to convert the biomass into the biofuels. HTL experiments on Algae-Helix and Salicornia at 200°C-350°C and 430psi were performed to investigate the effect of temperature on the biocrude yield of the respective biomass used. The effect of the biomass mixture (co-liquefaction) of Salicornia and algae on the amount of biocrude produced was also explored. The biocrude and biochar (by-product) obtained from the hydrothermal liquefaction process were also analyzed using thermogravimetric analyzer (TGA). The maximum biocrude yield for the algae-helix biomass and for the Salicornia biomass were both obtained at 300°C which were 34.63% and 7.65% respectively. The co-liquefaction of the two biomasses by 50:50 provided a maximum yield of 17.26% at 250°C. The co-liquefaction of different ratios explored at 250°C and 300°C concluded that Salicornia to algae-helix ratio of 20:80 produced the highest yields of 22.70% and 31.97%. These results showed that co-liquefaction of biomass if paired well with the optimizing temperature can produce a high biocrude yield. The TGA profiles investigated have shown that salicornia has higher levels of ash content in comparison with the algae-helix. It was then recommended that for a mixture of algae and Salicornia, large-scale biofuel production should be conducted at 250℃ in a 20:80 salicornia to algae biocrude ratio, since it lowers energy needs. The high biochar content left can be recycled to optimize biomass, and prevent wastage.
ContributorsLuboowa, Kato Muhammed (Co-author) / Laideson, Maymary (Co-author) / Deng, Shuguang (Thesis director) / Nielsen, David (Committee member) / Chemical Engineering Program (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Cyanobacteria have the potential to efficiently produce L-serine, an industrially important amino acid, directly from CO2 and sunlight, which is a more sustainable and inexpensive source of energy as compared to current methods. The research aims to engineer a strain of Cyanobacterium Synechococcus sp. PCC 7002 that increases L-serine production by mutating regulatory mechanisms that natively inhibit its production and encoding an exporter. While an excess of L-serine was not found in the supernatant of the cell cultures, with further fine tuning of the metabolic pathway and culture conditions, high titers of L-serine can be found. With the base strain engineered, the work can be extended and optimized by deleting degradation pathways, tuning gene expression levels, optimizing growth conditions, and investigating the effects of nitrogen supplementation for the strain.
ContributorsAbed, Omar (Author) / Nielsen, David (Thesis director) / Jones, Christopher (Committee member) / Chemical Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The field of bioprocess engineering has become an increasingly popular route to produce chemicals and fuels in a sustainable fashion. Bioprocessing is an interdisciplinary field that joins chemical engineering, metabolic engineering, and synthetic biology to tackle problems that will arise from the ongoing use of products derived from non-renewable resources. This study will overlook two effective tools that are widely used in the bioprocessing field. The first tool that was studied was strain optimization for biochemical production. This involves genetic manipulation of microbial hosts to create strains that are more efficient at producing the desired products. The second tool that was studied was adaptive laboratory evolution which is used to enhance overall cellular fitness. Enhancing the overall fitness and efficiency of these microbial production factories, allows for innovation and growth in the biochemical industry. Creating sustainable and renewable solutions for both specialty and commodity chemicals.
Strain optimization was specifically studied by enhancing inorganic carbon uptake in synechococcus sp. 7002. It is desired to have both high flux and high affinity transport for the rapid and efficient uptake of HCO3- for enhanced cell growth. The results found that the regulatory gene for carbon transporters in synechococcus genome was successfully deleted. Increasing the toxicity limits of 2-Phenylethanol was done by using adaptive laboratory evolution (ALE). ALE is a widely used practice in biotechnology studies to gain insights on mechanisms of molecular evolution and to better define the functionality of microbial cell factories. It was found that after growing E. coli BW25113 under selective conditions the genome evolved for a higher fitness medium with an increased concentration of 2-Phenylethanol. Overall, two key tools used in bioprocess engineering were successful studied to gain a better insight on the future of biochemical production industry.
Strain optimization was specifically studied by enhancing inorganic carbon uptake in synechococcus sp. 7002. It is desired to have both high flux and high affinity transport for the rapid and efficient uptake of HCO3- for enhanced cell growth. The results found that the regulatory gene for carbon transporters in synechococcus genome was successfully deleted. Increasing the toxicity limits of 2-Phenylethanol was done by using adaptive laboratory evolution (ALE). ALE is a widely used practice in biotechnology studies to gain insights on mechanisms of molecular evolution and to better define the functionality of microbial cell factories. It was found that after growing E. coli BW25113 under selective conditions the genome evolved for a higher fitness medium with an increased concentration of 2-Phenylethanol. Overall, two key tools used in bioprocess engineering were successful studied to gain a better insight on the future of biochemical production industry.
ContributorsSteeber, Gavin Lyle (Author) / Nielsen, David (Thesis director) / Jones, Christopher (Committee member) / Chemical Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Flavonoids are important biomolecules with a variety of pharmaceutical and agricultural applications. Currently, isolating these compounds is done by plant extraction, however this process is hindered by large land and energy requirements. Previous groups have aimed to overcome these challenges by engineering microbes to produce these important compounds, however this is largely bottlenecked by the lack of intercellular malonyl-CoA availability. To remedy this, the genes matB and matC have been identified as coding for malonyl-CoA synthase and a putative dicarboxylate carrier protein, respectively. Other works have successfully engineered two variants, Streptomyces coelicolor and Rhizobium trifolii, of these genes into Escherichia coli, however this has yet to be accomplished in Gram-positive Corynebacterium glutamicum. Additionally, other groups have neglected to attempt tuning these genes with respect to one another by inserting in front of different inducible promoters. This study has successfully assembled two plasmids containing the Streptomyces coelicolor and Rhizobium trifolii variants of both matB and matC. Preliminary fermentations and GCMS results confirmed that little to none naringenin was produced without the matB-matC module. Additionally, preliminary fermentations revealed that the DelAro1 and DelAro3 strains can be used to reduce metabolism of aromatics like naringenin.
ContributorsRonstadt, Jason (Author) / Varman, Arul (Thesis director) / Nielsen, David (Committee member) / Liu, Fang (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor)
Created2022-05