BENG0006 Bioprocess Analysis

• This coursework will be assessed by a submitted document showing hand-written solution to the answers to the CW brief (see next page).
• Include any assumption, basis of calculation, block flow diagram, mass balance tables, etc. Write clearly to show your working. State any assumptions and justify your answers to questions. Make your handwriting as clear and readable as possible.
• This CW is 15% of the module mark. Marks break down are provided in the CW brief.
• Gateway assessment:
• You need to pass all in-class quizzes each week (Quiz 1 to Quiz 5) to be able to access the submission portal. If you miss an in- class quiz, you will also need to complete 1 additional quiz. Quizzes are timed up to 15 minutes. See Moodle announcement, Weekly Timetable and Assessment Overview on Moodle for information about the quizzes.
• Preparing your submission:
• NOT WRITE YOUR NAME on the document. We mark these anonymously and we will know the identity of the submitter via Moodle.
• Use A4 paper, it doesn’t matter whether this is lined or not, or what colour.
• Ideally, use black or blue pens, other pen colours are fine so long as they are clear and high contrast with your paper.
• Submissions from Tablets (even paper tablets) are not allowed and will not be marked.
• not use pencils as these are sometimes difficult to read.
• [Optional] You may want to use a cover page to indicate which pages are useful for each question or sub-question in the brief.o Scan the pages using your phone and save as one PDF file (you can use Microsoft OneDrive – this is free via your UCL account, or other software). If you do not know how to do this, please contact UCL ISD: https://www.ucl.ac.uk/isd/help-support
• Submit the document via Moodle > Assessment and Submission Portals > Coursework 2
• You can submit drafts, so it is better to submit one before the deadline than submit late.
• Deadlines and late penalties: https://www.ucl.ac.uk/academic- manual/chapters/chapter-4-assessment-framework-taught- programmes/section-3-module-assessment#3.11

[Note as of 20th January 2025: This document was updated to include the marking criteria for #2 and to show the total mark is 15 which reflects the % points contribution of this coursework to the module mark. The problem set in the coursework brief is the same.]

• [6 marks] A new monoclonal antibody product (Mabs) is produced in a 10000 L stainless steel bioreactor. The product titre is 2.0 g L-1. The cell culture harvest is processed through a centrifuge (85% yield), depth filter (88% yield), affinity chromatography (98% yield), viral inactivation (98% yield), a sequence of two ion-exchange (IEX) chromatography steps (95% yield for each IEX), a viral filtration step (90% yield), a crossflow filter for concentration (90% yield), the same crossflow filter is used for diafiltration (i.e. buffer exchange) (95% yield), and finally a filtration step for bioburden reduction (95%). The concentration of the product streams after affinity chromatography, the first IEX step and the final filtration are 7.5 g L-1, 12.8 g L-1 and 100.0 g L-1, respectively.
• Draw a block diagram of the process, including relevantinformation such as volumes or product concentration, ifavailable. [1 mark]
• colleague asked if a flocculation step would be useful in this process. Explain why (or why not) this step is not needed. Limit your answer to 5 sentences max. [1 marks]
• a complete buffer exchange is achieved after exchanging 7 volumes of buffer, estimate the minimum size of buffer tank needed to supply the crossflow filter for diafiltration. [1 marks]
• the 1 dose of therapy requires 240 mg of Mabs, how many doses are produced in 1 year? Assume plant capacity enables the production of 20 batches per year. [1 mark]o Given the following additional information: a cell culture takes 2 weeks; DSP activities takes a total of 1 week and the facility operates at 48 weeks in a year; demonstrate how the addition of 1 more 10 m3 bioreactor can increase the number of doses produced by this facility without needing additional DSP equipment. [2 marks]
• [9 marks] Consider a process to recover an extracellular product expressed in microbial cells. The total fermentation broth volume is 2000 L. The cell concentration in the broth is 150 g L-1, product concentration is 2 g L-1 and the relevant impurities were measured at 0.3 g L-1. The density of similar bacterial cells can be found in [1].

The CTO of the company also want to ensure that the process is sustainableand environment-friendly. This is typically measured by the E factor, the ratioof kg waste/ kg product [2]. However, for early process steps within abioprocess sequence, it may not reflect the actual waste of the process stepas the waste steam may be recovered in further downstream steps. As asubstitute, process mass intensity offers a different metric (PMI = total massinto the process (kg)/ mass of product (kg)) [3].You manager said that if a single step centrifugation of the feed does notmeet all these requirements, then the following solutions (a) or (b) areproposed.

Reference:

1. van Hee, P., Hoeben, M.A., van der Lans, R.G.J.M. and van der Wielen, L.A.M. (2006), Strategy for selection of methods for separation of bioparticles from particle mixtures. Biotechnol. Bioeng., 94: 689-709.https://doi.org/10.1002/bit.20885

2. Sheldon, R.A., Bode, M.L, Akakios, S.G. (2022). Metrics of greenchemistry: Waste minimization, Current Opinion in Green andSustainable Chemistry,Volume 33,100569,https://doi.org/10.1016/j.cogsc.2021.100569 .

3. Jimenez-Gonzalez, C., Ponder, C.S., Broxterman, Q. B., Manley, J.B.(2011). Using the Right Green Yardstick: Why Process Mass IntensityIs Used in the Pharmaceutical Industry To Drive More SustainableProcesses. Org. Process Res. Dev. 2011, 15, 4, 912–917.https://doi.org/10.1021/op200097d