Sue Harrison
University of Cape Town, Chemical Engineering, Faculty Member
- I am professor in Chemical Engineering and held the 15-year term South African Research Chair in Bioprocess Engineeri... moreI am professor in Chemical Engineering and held the 15-year term South African Research Chair in Bioprocess Engineering at the University of Cape Town since 2008. With 30 years’ experience as an academic at the University of Cape Town, my profile is balanced between teaching, postgraduate supervision, research and management and leadership at the research centre / institute, departmental, faculty and university level. My research profile in bioprocess engineering research is focused on microbial systems, studying microbial physiology, the biological response to stress incurred in process systems, process kinetics, productivity and product induction. These are key to the configuring of bioprocesses across a range of applications, from the production of biochemical products and fine chemicals through the beneficiation of minerals ores using biohydrometallurgy to waste processing and remediation. My work spans recombinant microbial systems through to mixed microbial communities, with a strong interest in microbial ecology and the relationship between community composition, metabolic function and process performance. I have a strong interest in bioprocess design and integrated process systems, an example of which is the waste biorefinery as an important element of the circular economy. I seek to use an integrated understanding of biological and engineering interactions within these systems in their design with particular focus on energy efficiency and maximising resource productivity. I focus on sustainable processes, specifically the role of bioprocesses in enhancing sustainability of the process industry and seek to maintain a balance between fundamental studies, applied engineering science and engaged scholarship. Through inter- and transdisciplinary research, I focus on wicked problems in the context of sustainable development of mineral resources and water sensitive systems. I am director of the Centre for Bioprocess Engineering Research and was the founding director of UCT’s interdisciplinary research institute Future Water and a founding member of the Minerals to Metals initiative at UCT, building strong teams of complementary researchers. Currently I hold the position of Deputy Vice-Chancellor: Research and Internationalisation at the University of Cape Town.edit
Research Interests:
With the steady advancement of medicine and the healthcare industry, the demand for recombinant biotherapeutics drugs and vaccines has increased in the last two decades. This has put substantial pressure on the biopharma industry to meet... more
With the steady advancement of medicine and the healthcare industry, the demand for recombinant biotherapeutics drugs and vaccines has increased in the last two decades. This has put substantial pressure on the biopharma industry to meet the increasing need for treatment of prevailing and new diseases. Different technologies and bioreactor designs have been developed over the years to ensure safe and economical manufacturing of biopharmaceutical products by attaining high cell densities and longevities for extended periods of time. Bioreactors are the backbone of the bioprocessing industry albeit each bioreactor design has its advantages and disadvantages. A comprehensive design suitable for wide varieties of cell lines to produce high‐yielding products with the lowest cost and risk in the shortest span of time is sought. This paper focuses on evaluating the engineering aspects of currently available bioreactor designs and their suitability for mammalian cell cultures.
Research Interests:
This collection curates content from the various CeBER Projects in Wastewater Biorefineries.
Research Interests:
This data explores the locations of potential markets for sulfide-enriched coal waste as well as how much might be applied on soil for amelioration. This then placed me in a position to estimate the transport costs for the material from... more
This data explores the locations of potential markets for sulfide-enriched coal waste as well as how much might be applied on soil for amelioration. This then placed me in a position to estimate the transport costs for the material from their source coal mines to destination regions. The ability of farmland to absorb the entire stream was considered as well as a first attempt at environmental costing using a carbon footprinting calculation.
Plant microbial fuel cells are a recently developed technology that exploits photosynthesis in vascular plants by harnessing solar energy and generating electrical power. In this study, the model moss species Physcomitrella patens, and... more
Plant microbial fuel cells are a recently developed technology that exploits photosynthesis in vascular plants by harnessing solar energy and generating electrical power. In this study, the model moss species Physcomitrella patens, and other environmental samples of mosses, have been used to develop a non-vascular bryophyte microbial fuel cell (bryoMFC). A novel three-dimensional anodic matrix was successfully created and characterized and was further tested in a bryoMFC to determine the capacity of mosses to generate electrical power. The importance of anodophilic microorganisms in the bryoMFC was also determined. It was found that the non-sterile bryoMFCs operated with P. patens delivered over an order of magnitude higher peak power output (2.6 ± 0.6 µW m(-2)) than bryoMFCs kept in near-sterile conditions (0.2 ± 0.1 µW m(-2)). These results confirm the importance of the microbial populations for delivering electrons to the anode in a bryoMFC. When the bryoMFCs were operated with e...
Research Interests:
The production of acetone, butanol, and ethanol by two immobilized, sporulation-deficient (spo) Clostridium acetobutylicum P262 mutants which were held in the solventogenic phase was investigated. The spoA2 mutant, which was an... more
The production of acetone, butanol, and ethanol by two immobilized, sporulation-deficient (spo) Clostridium acetobutylicum P262 mutants which were held in the solventogenic phase was investigated. The spoA2 mutant, which was an early-sporulation mutant and did not form a forespore septum, produced higher solvent yields than did the spoB mutant which was a late-sporulation mutant and was blocked at a stage after forespore septum formation. The spoA2 mutant was also granulose and capsule negative. In a conventional batch fermentation, the wild-type strain produced 15.44 g of solvents per liter after 50 h at a productivity of 7.41 g of solvents per liter per day. The spoA2 mutant produced 15.42 g of solvents per liter at a productivity of 72.4 g of solvents per liter per day, with a retention time of 2.4 h in a continuous immobilized cell system employing a fluidized bed reactor. This represents a major advance, since the immobilization of wild-type cells showed similar increases in pr...
Research Interests:
Although it appears relatively simple in principle, the processes involved in heap bioleaching are in fact extremely complex. It is the contention of the authors that a rigorous and systematic understanding of these complexities,... more
Although it appears relatively simple in principle, the processes involved in heap bioleaching are in fact extremely complex. It is the contention of the authors that a rigorous and systematic understanding of these complexities, expressed in a comprehensive model, will enable the design of efficient and economic heap bioleach operations, not only for chalcocite/covellite/bornite based ores, but also for those
Research Interests:
Research Interests:
Research Interests:
Research Interests:
This study explored technologies for recovering energy from wastewater through production of biomass, combustion and gasification, generation of biogas, production of bioethanol, heat recovery and microbial fuel cells. A first order... more
This study explored technologies for recovering energy from wastewater through production of biomass, combustion and gasification, generation of biogas, production of bioethanol, heat recovery and microbial fuel cells. A first order desktop analysis of the potential for applying these solutions to wastewaters in South Africa revealed that 3 200 to 9 000 MWth of energy has potential for recovery, equating to at most 7% of South Africa’s current electrical power supply. Formal and informal animal husbandry, fruit and beverage industries and domestic blackwater were identified as wastewaters with the greatest potential for energy recovery. Of the reviewed technologies, anaerobic digestion shows applicability to the widest range of feedstocks. Net energy generated, reduction in pollution, and water reclamation are identified as the main benefits, but additional benefits such as certified emission reductions, fertiliser production and the production of secondary products may dictate the ...
Research Interests:
Research Interests:
Research Interests:
Research Interests: Thermodynamics, Water, Metabolism, Kinetics, Acid Mine Drainage, and 15 moreMultidisciplinary, Bioreactor, Sulfides, Sulfate reducing Bacteria, Fermentation, Bioreactors, Oxidation, Stoichiometry, Reaction Mechanism, Sulfate reduction, Residence Time, Lactic Acid, Oxidation-Reduction, Carbon Source, and Sulfates
Research Interests:
Research Interests:
Research Interests: Mechanical Engineering, Chemical Engineering, Kinetics, Biomass, Population structure, and 15 moreBioreactor, Bacteria, Fermentation, Bioprocessing, Bioreactors, Reactor, Oxidation, Chemical Engineering Science, Affinity, Residence Time, Environment, Carbon Source, fermenter, Dilution, and kinetic analysis
Thiocyanate (SCN(-) ) is a toxic compound that forms when cyanide (CN(-) ), used to recover gold, reacts with sulfur species. SCN(-) -degrading microbial communities have been studied, using bioreactors fed synthetic wastewater. The... more
Thiocyanate (SCN(-) ) is a toxic compound that forms when cyanide (CN(-) ), used to recover gold, reacts with sulfur species. SCN(-) -degrading microbial communities have been studied, using bioreactors fed synthetic wastewater. The inclusion of suspended solids in the form of mineral tailings, during the development of the acclimatized microbial consortium, led to the selection of an active planktonic microbial community. Preliminary analysis of the community composition revealed reduced microbial diversity relative to the laboratory-based reactors operated without suspended solids. Despite minor upsets during the acclimation period, the SCN(-) degradation performance was largely unchanged under stable operating conditions. Here, we characterized the microbial community in the SCN(-) degrading bioreactor that included solid particulate tailings and determined how it differed from the biofilm-based communities in solids-free reactor systems inoculated from the same source. Genome-ba...
Research Interests:
Research Interests:
Semi-passive remediation systems have the potential to treat low-volume, sulphate-rich, mining impacted waters in a cost-effective and sustainable way. This paper describes the proof of concept evaluation of a hybrid linear flow channel... more
Semi-passive remediation systems have the potential to treat low-volume, sulphate-rich, mining impacted waters in a cost-effective and sustainable way. This paper describes the proof of concept evaluation of a hybrid linear flow channel reactor, capable of sustaining efficient biological sulphate reduction and partial oxidation of the sulphide product to elemental sulphur. Key elements include the presence of a sulphate-reducing microbial community, immobilised onto carbon fibres and the rapid development of a floating biofilm at the air-liquid interface. The biofilm consists of heterotrophic species and autotrophic sulphide oxidisers. It impedes oxygen mass transfer into the bulk volume and creates a suitable pH-redox microenvironment for partial sulphide oxidation. Demonstration of the concept was successful, with near complete reduction of the sulphate in the feed (1 g/l), effective management of the sulphide generated (95-100% removal) and recovery of a portion of the sulphur by...
Gold ore processing uses cyanide (CN(-) ), which often results in large volumes of thiocyanate- (SCN(-) ) contaminated wastewater requiring treatment. Microbial communities can degrade SCN(-) and CN(-) , but little is known about their... more
Gold ore processing uses cyanide (CN(-) ), which often results in large volumes of thiocyanate- (SCN(-) ) contaminated wastewater requiring treatment. Microbial communities can degrade SCN(-) and CN(-) , but little is known about their membership and metabolic potential. Microbial-based remediation strategies will benefit from an ecological understanding of organisms involved in the breakdown of SCN(-) and CN(-) into sulfur, carbon and nitrogen compounds. We performed metagenomic analysis of samples from two laboratory-scale bioreactors used to study SCN(-) and CN(-) degradation. Community analysis revealed the dominance of Thiobacillus spp. whose genomes harbor a previously unreported operon for SCN(-) degradation. Genome-based metabolic predictions suggest that a large portion of each bioreactor community is autotrophic, relying not on molasses in reactor feed, but using energy gained from oxidation of sulfur compounds produced during SCN(-) degradation. Heterotrophs, including a ...
Research Interests:
Phage typically have small genomes and depend on their bacterial hosts for replication. DNA sequenced from many diverse ecosystems revealed hundreds of huge phage genomes, between 200 kbp and 716 kbp in length. Thirty-four genomes were... more
Phage typically have small genomes and depend on their bacterial hosts for replication. DNA sequenced from many diverse ecosystems revealed hundreds of huge phage genomes, between 200 kbp and 716 kbp in length. Thirty-four genomes were manually curated to completion, including the largest phage genomes yet reported. Expanded genetic repertoires include diverse and new CRISPR-Cas systems, tRNAs, tRNA synthetases, tRNA modification enzymes, translation initiation and elongation factors, and ribosomal proteins. Phage CRISPR-Cas systems have the capacity to silence host transcription factors and translational genes, potentially as part of a larger interaction network that intercepts translation to redirect biosynthesis to phage-encoded functions. In addition, some phage may repurpose bacterial CRISPR-Cas systems to eliminate competing phage. We phylogenetically define major clades of huge phage from human and other animal microbiomes, oceans, lakes, sediments, soils and the built enviro...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Multiple mini-column reactors, loaded with identically constructed ore samples representing grab samples of a larger heap, were used to study the behaviour of solution tracers to elucidate solution diffusion, dispersion and transport. The... more
Multiple mini-column reactors, loaded with identically constructed ore samples representing grab samples of a larger heap, were used to study the behaviour of solution tracers to elucidate solution diffusion, dispersion and transport. The tracers were either introduced to the ore bed as a pulse, included during agglomeration of the ore or introduced to the system by submerging the ore bed. These methods of tracer introduction allowed for the characterisation of flow interchange in unsteady state systems. The resulting concentration-time distribution curves were analysed to allow characterisation of flow dispersion and diffusion, which facilitates exchange between the fast flowing and largely stagnant liquid phases. Preliminary results support the presence of distinct stagnant and flowing regions within the agglomerated ore bed. Agglomeration with the tracer promotes increased retention on the ore; potentially enhancing microbial transport via increased solution exchange after the in...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Engineering, Technology, Protein adsorption, High Pressure, Chromatography, and 15 moreBiotechnology, Adsorption, Homogenization, Biological Sciences, Saccharomyces cerevisiae, Diffusion, Hydrodynamics, Solubility, Microorganism, Particle Size, DBC, RTD, Particle Size Distribution, C, and Static Electricity
Research Interests:
Research Interests:
Research Interests:
Research Interests:
The energy efficiency of the cell disruption process for the recovery of intracellular proteins depends on the physical strength of the cell wall of the microorganism and on the intracellular location of the target enzymes, also the way... more
The energy efficiency of the cell disruption process for the recovery of intracellular proteins depends on the physical strength of the cell wall of the microorganism and on the intracellular location of the target enzymes, also the way in which the stress is applied (effectiveness). Heat ...