15 research outputs found

    Enhancing students’ digital skills through a Biotechnology & Bioprocessing module designed for chemical engineers

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    The transformation of the chemical engineering profession is occurring in response to the industry needs of the rapidly-developing bioeconomy and biosector across Europe. To meet these requirements, a new Biotechnology and Bioprocessing module has been designed and offered to Chemical Engineering undergraduates at Aston University, UK. This module bridges chemical engineering and biosciences disciplines, providing students with new skills and knowledge to better understand the opportunities available to chemical engineering professionals within the biosector. Here, we evaluate how the use of digital technologies enhances the student’s learning experience using a range of innovative learning activities delivered in a digital environment. The student’s and author’s perceptions are evaluated, and future improvements identified. This module will contribute to preparing graduates for a successful career in the highly competitive landscape of the bioeconomy and biosector. This pedagogical approach prepares graduates for, hybrid and remote study and working patterns and; changing industrial and digital learning demands

    Development of a simple intensified fermentation strategy for growth of Magnetospirillum gryphiswaldense MSR-1:Physiological responses to changing environmental conditions

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    The development of a simple pH-stat fed-batch fermentation strategy for the production of Magnetospirillum gryphiswaldense MSR-1 and magnetosomes (nanoscale magnetic organelles with biotechnological applications) is described. Flow cytometry was exploited as a powerful analytical tool for process development, enabling rapid monitoring of cell morphology, physiology and polyhydroxyalkanoate production. The pH-stat fed-batch growth strategy was developed by varying the concentrations of the carbon source (lactic acid) and the alternative electron acceptor (sodium nitrate) in the feed. Growth conditions were optimized on the basis of biomass concentration, cellular magnetism (indicative of magnetosome production), and intracellular iron concentration. The highest biomass concentration and cellular iron content achieved were an optical density at 565 nm of 15.5 (equivalent to 4.2 g DCW·L−1) and 33.1 mg iron·g−1 DCW, respectively. This study demonstrates the importance of analyzing bacterial physiology during fermentation development and will potentially aid the industrial production of magnetosomes, which can be used in a wide range of biotechnology and healthcare applications

    Production of microbial lipids utilizing volatile fatty acids derived from wastepaper: A biorefinery approach for biodiesel production

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    Volatile fatty acids (VFAs) derived from organic wastes are being considered as low-cost feedstock for microbial lipid production as a valuable alternative to plant derived oils/biodiesel. In this study, VFAs were produced from anaerobic open culture fermentation of wastepaper and subsequently, used as a feedstock for lipid production by Cryptococcus curvatus. Total VFAs, yield and productivity achieved from waste office paper (WOP) and waste newspaper (WNP) were 17.3 and 10.2 g/L, 0.17 and 0.10 g/g TS, and 0.86 and 0.51 g/L/day, respectively. Biomass, lipid content and productivity achieved utilizing VFAs derived from WOP and WNP were 4.3 and 2.9 g/L, 41.2 and 27.7% DCW, and 0.037 and 0.033 g/L/h, respectively. The dominance of fatty acids such as oleic, palmitic, stearic and linoleic acid in the lipids suggests a high level of similarity with plant/vegetable oils used for biodiesel production. Therefore, VFAs derived from wastepaper could be potentially used as feedstock to produce microbial lipids towards cost-effective production of biodiesel

    Process Intensification at the expression system level for the production of 1-phosphate aldolase in antibiotic-free E. coli fed-batch cultures

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    In order to successfully design expression systems for industrial biotechnology and biopharmaceutical applications; plasmid stability, capacity to efficiently synthesize the desired product and the use of selection markers that are acceptable to regulatory bodies are of utmost importance. In this work we demonstrate the application of a set of engineered strains – with different features namely, antibiotic vs auxotrophy marker; two-plasmids vs single plasmid expression system; expression levels of the repressor protein (LacI) and the auxotrophic marker (glyA) – in high cell density cultures to evaluate their suitability to be used in bioprocess conditions that resemble industrial production. Results revealed that the first generation of engineered strain showed a 50 % reduction in fuculose-1-phosphate aldolase (FucA) production compared to the reference system (165 ± 13 mg FucA·g-1 DCW and 806 ± 12 AU·g-1 DCW) which is commercially available from QIAGEN and uses an antibiotic selection marker. The over-transcription of the glyA gene was found to be a major factor responsible for the metabolic burden leading to the decrease in FucA yield. The second- and third-generation of E. coli strains presented an increase in FucA production, being 202 ± 18 mg-1 FucA·g-1 DCW and 1176 ± 19 AU·g-1 DCW, and 1322 ± 19 AU·g-1 DCW and 245 ± 13 mg-1 FucA·g-1 DCW, respectively. Both strains presented a fitness improvement after tuning the expression levels of the glyA gene and the deletion of the ampicillin resistance gene (bla) from the plasmid were carried out, respectively. The third-generation expression system is antibiotic-free, autotrophy-selection based and single-plasmid and is capable to produce FucA at similar levels compared to the original commercial expression system. Hence, our expression system possesses advantageous features compared to the commercial one and proved to have the potential to become an attractive platform for the production of recombinant proteins in a wide range of industrial biotechnology applications

    A scalable biomanufacturing platform for bacterial magnetosomes

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    An integrated scalable platform for fermentative production and downstream processing of bacterial magnetosome products is advanced. Long magnetosome chains, high cellular magnetism, and low numbers of polyhydroxyalkanoate granules were obtained during the exponential growth phase of a two-stage continuous high cell density fermentation of M. gryphiswaldense MSR-1. Centrifugally concentrated 20% (w/v) suspensions of exponential phase cells were disrupted with high efficiency (~92%) in a single pass through a Constant Systems Cell Disruptor operated at 10 kpsi, releasing ~75% of the cellular iron. Magnetosomes were recovered in partially purified form from crude whole cell disruptates by rotor-stator high-gradient magnetic separation. Further purification/polishing was achieved by magnetically enhanced density separation in an aqueous micellar two-phase system (a new technique developed in this work as a low-cost alternative to sucrose gradient ultracentrifugation). The unoptimised 4-step process delivered highly purified magnetosomes (ca. 50 and 80-fold with respect to polyhydroxyalkanoate and protein) in >50% yield, with no evidence of crystal coat damage, acceptable reduction (~35%) in median magnetosome chain length, and magnetic properties (pot-bellied hysteresis loop, coercivity = 9.8 mT, ‘squareness’ = 0.32) expected of isolated magnetosome chains. Though demonstrated in batch mode, the platform displays potential for end-to-end continuous manufacture of future magnetosome-based products

    Process integration for efficient conversion of cassava peel waste into polyhydroxyalkanoates

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    Polyhydroxyalkanoates (PHA) are biodegradable polyesters that can be produced from renewable resources. However, PHA biomanufacturing is costly compared to petrochemical-based plastics. A promising solution consists of using cassava (Manhiot esculenta) waste, abundant biomass in developing countries, as a carbon source for PHA production. This study involved characterising untreated and acid-hydrolysed cassava peel (CP) to confirm the degradation of polysaccharides into fermentable sugars after pre-treatment. A chemical and biological integrated process was developed, optimising the pre-treatment using a central composite design. The highest conversion of CP into reducing sugars was 97% (w/w) using 3 M H2SO4, 120 min and 90 ºC. The ability of Cupriavidus necator to grow on CP hydrolysate and produce PHA was screened resulting in up to OD600 15.8 and 1.5 g/L of PHA (31% (gPHA/gDCW)). Flow cytometry allowed rapid, simple, and high-throughput assessment of PHA content. These findings pave the way for developing a biorefinery platform for PHA production from cassava waste

    Bioinformatic characterization of a triacylglycerol lipase produced by Aspergillus flavus isolated from the decaying seed of Cucumeropsis mannii

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    Lipases are enzymes of industrial importance responsible for the hydrolysis of ester bonds of triglycerides. A lipolytic fungus was isolated and subsequently identified based on the ITS sequence analysis as putative Aspergillus flavus with accession number LC424503. The gene coding for extracellular triacylglycerol lipase was isolated from Aspergillus flavus species, sequenced, and characterised using bioinformatics tools. An open reading frame of 420 amino acid sequence was obtained and designated as Aspergillus flavus lipase (AFL) sequence. Alignment of the amino acid sequence with other lipases revealed the presence GHSLG sequence which is the lipase consensus sequence Gly-X1-Ser-X2-Gly indicating that it a classical lipase. A catalytic active site lid domain composed of TYITDTIIDLS amino acids sequence was also revealed. This lid protects the active site, control the catalytic activity and substrate selectivity in lipases. The 3-Dimensional structural model shared 34.08% sequence identity with a lipase from Yarrowia lipolytica covering 272 amino acid residues of the template model. A search of the lipase engineering database using AFL sequence revealed that it belongs to the class GX-lipase, superfamily abH23 and homologous family abH23.02, molecular weight and isoelectric point values of 46.95 KDa and 5.7, respectively. N-glycosylation sites were predicted at residues 164, 236 and 333, with potentials of 0.7250, 0.7037 and 0.7048, respectively. O-glycosylation sites were predicted at residues 355, 358, 360 and 366. A signal sequence of 37 amino acids was revealed at the N-terminal of the polypeptide. This is a short peptide sequence that marks a protein for transport across the cell membrane and indicates that AFL is an extracellular lipase. The findings on the structural and molecular properties of Aspergillus flavus lipase in this work will be crucial in future studies aiming at engineering the enzyme for biotechnology applications

    Valorising cassava peel waste into plasticized polyhydroxyalkanoates blended with polycaprolactone with controllable thermal and mechanical properties

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    Approximately 99% of plastics produced worldwide were produced by the petrochemical industry in 2019 and it is predicted that plastic consumption may double between 2023 and 2050. The use of biodegradable bioplastics represents an alternative solution to petroleum-based plastics. However, the production cost of biopolymers hinders their real-world use. The use of waste biomass as a primary carbon source for biopolymers may enable a cost-effective production of bioplastics whilst providing a solution to waste management towards a carbon–neutral and circular plastics economy. Here, we report for the first time the production of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) with a controlled molar ratio of 2:1 3-hydroxybutyrate:3-hydroxvalerate (3HB:3HV) through an integrated pre-treatment and fermentation process followed by alkaline digestion of cassava peel waste, a renewable low-cost substrate, through Cupriavidus necator biotransformation. PHBV was subsequently melt blended with a biodegradable polymer, polycaprolactone (PCL), whereby the 30:70 (mol%) PHBV:PCL blend exhibited an excellent balance of mechanical properties and higher degradation temperatures than PHBV alone, thus providing enhanced stability and controllable properties. This work represents a potential environmental solution to waste management that can benefit cassava processing industries (or other crop processing industries) whilst developing new bioplastic materials that can be applied, for example, to packaging and biomedical engineering

    Performance and application of an open source automated magnetic optical density meter for analyzing magnetotactic bacteria

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    We present a spectrophotometer (optical density meter) combined with electromagnets dedicated to the analysis of magnetotactic bacteria. We have ensured that our system, called MagOD, can be easily reproduced by providing the source of the 3D prints for the housing, electronic designs, circuit board layouts, and microcontroller software. We compare the performance of this novel system to existing adapted commercial spectrophotometers. In addition, we demonstrate its use by analyzing the absorbance of magnetotactic bacteria as a function of their orientation with respect to the light path and their speed of reorientation after the field has been rotated by 90o. We continuously monitored the development of a culture of magnetotactic bacteria over a period of five days, and measured the development of their velocity distribution over a period of one hour. Even though this dedicated spectrophotometer is relatively simple to construct and cost-effective, a range of magnetic field-dependent parameters can be extracted from suspensions of magnetotactic bacteria. Therefore, this instrument will help the magnetotactic research community to understand and apply this intriguing micro-organism

    An open-source automated magnetic optical density meter for analysis of suspensions of magnetic cells and particles

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    We present a spectrophotometer (optical density meter) combined with electromagnets dedicated to the analysis of suspensions of magnetotactic bacteria. The instrument can also be applied to suspensions of other magnetic cells and magnetic particles. We have ensured that our system, called MagOD, can be easily reproduced by providing the source of the 3D prints for the housing, electronic designs, circuit board layouts, and microcontroller software. We compare the performance of our system to existing adapted commercial spectrophotometers. In addition, we demonstrate its use by analyzing the absorbance of magnetotactic bacteria as a function of their orientation with respect to the light path and their speed of reorientation after the field has been rotated by 90°. We continuously monitored the development of a culture of magnetotactic bacteria over a period of 5 days and measured the development of their velocity distribution over a period of one hour. Even though this dedicated spectrophotometer is relatively simple to construct and cost-effective, a range of magnetic field-dependent parameters can be extracted from suspensions of magnetotactic bacteria. Therefore, this instrument will help the magnetotactic research community to understand and apply this intriguing micro-organism
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