Teaching bioprocess engineering to undergraduates: Multidisciplinary hands-on training in a one-week practical course

Abstract

Bioprocess engineering is a highly interdisciplinary field of study which is strongly benefited by practical courses where students can actively experience the interconnection between biology, engineering, and physical sciences. This work describes a lab course developed for 2nd year undergraduate students of bioprocess engineering and related disciplines, where students are challenged with a real-life bioprocess-engineering application, the production of recombinant protein in a fed-batch process. The lab course was designed to introduce students to the subject of operating and supervising an experiment in a bioreactor, along with the analysis of collected data and a final critical evaluation of the experiment. To provide visual feedback of the experimental outcome, the organism used during class was Escherichia coli which carried a plasmid to recombinantly produce enhanced green fluorescent protein (eGFP) upon induction. This can easily be visualized in both the bioreactor and samples by using ultraviolet light. The lab course is performed with bioreactors of the simplest design, and is therefore highly flexible, robust and easy to reproduce. As part of this work the implementation and framework, the results, the evaluation and assessment of student learning combined with opinion surveys are presented, which provides a basis for instructors intending to implement a similar lab course at their respective institution.

Keywords: bioprocess engineering; bioreactor; biotechnology; laboratory exercise.

Figure 1

Overview of the general schedule, teaching units, and appropriate teaching methods.

Figure 2

The bioreactor and peripherals used during the lab course. (a) Peristaltic precision feed‐pump. (b) Bottle with feed solution on a scale. (c) Bioreactor with 1. glass vessel and stirrer, 2. acid/base feeding, 3. sampling valve, 4. exhaust gas analyzer.

Figure 3

Exemplary results from online and offline monitoring of the process. Online data are available for pO₂, x_O2, x_CO2, and the amount of acid and base added for adjustment of pH. Offline measurements as absolute values are provided for biomass, glucose, and acetate. Different modes of operation are indicated by orange vertical lines which indicate the transitions from batch phase (t = 0–6.5 h) to first fed‐batch (t = 6.5–10.5 h) and second fed‐batch (t = 10.5–30 h). Stirrer speed has been adjusted from 400 rpm to 500 rpm by process control software to enhance oxygen transfer to the culture broth at t = 3.5 h (indicated by a star), which results in a rise in pO₂ of no significance to the determination of substrate depletion. Biomass growth in the second fed‐batch is approximated by assuming exponential growth with µ = 0.1 h⁻¹ (dark green, solid line).

Figure 4

eGFP‐fluorescence at the end of the fermentation. (a) eGFP‐producing bacteria can easily be visualized in the glass vessel of the bioreactor by using UV light. (b) The process of eGFP‐production during the fermentation becomes apparent by comparing frozen cell‐pellets under UV light.

Figure 5

Student perception on their learning experience during the lab course. Presented data have been collected within the frame of the official evaluation of higher education at the Karlsruhe Institute of Technology (KIT), in a program established at all universities of the German state of Baden‐Wuerttemberg. Evaluation data were collected anonymously in written form on the last day of the lab‐course. The amount of students participating in the study were 57 (2012), 59 (2013), and 62 (2014), respectively.