Bioprocess engineering: Sybille Ebert to teach key biotechnological skills
Every single biotechnological production process is tested in shake flasks before it is gradually scaled up to eventually produce tons of platform chemicals or biofuels in cubic-metre sized fermenters. Prof. Dr. Sybille Ebert teaches the theory and practice of bioprocess engineering in the form of lectures and practical laboratory exercises to students at the Biberach University of Applied Sciences. The trained chemist and mathematician was appointed to the endowed chair of process engineering in biotechnology in summer 2013. The professorship is part of the university’s Industrial Biotechnology bachelor degree course.
Sybille Ebert, who grew up and studied in Baden-Württemberg, has a long-standing interest in biotechnology and has always remained in the field despite switching back and forth between white (industrial) and red (pharmaceutical) biotechnology. During our interview, Ebert pointed out that the differences between white and red biotechnology are of little relevance in the field of process engineering, and that neither are that far removed from cell culture.
PhD in the traditional field of white biotechnology
Sybille Ebert studied at the University of Tübingen and moved to Stuttgart in 1997 to do her doctorate on the microbial degradation of nitroaromatics in the Institute of Microbiology led by Professor Hans-Joachim Knackmuss at the University of Stuttgart. Her doctoral thesis, which she completed in 2001, focused on the biochemistry and genetics of the microbial degradation of 2,4-dinitrophenol and picric acid, a compound that is structurally similar to TNT.
In her thesis, Ebert specifically dealt with the degradation of water-soluble picric acid, which was used as a grenade explosive during WW1. Picric acid and 2,4-dinitrophenol are highly toxic compounds and are side products of nitrobenzene production. They accumulate in wastewater. Nitrobenzene is an organic compound produced on a large scale during the production of a broad range of chemicals. Ebert succeeded in showing that the activated sludge of wastewater treatment plants that contains the bacterial genera Rhodococcus and Nocardioides is able to mineralise these pollutants.
After her doctorate, the young scientist remained at the institute and became involved in a green chemistry project focusing on the synthesis of chemical compounds for use in the textile industry. These compounds have predetermined breaking points which enables the microorganisms to degrade them effectively.
12 years in industry
In 2001, Ebert joined Roche Vitamins' research laboratories in the Swiss city of Kaiseraugst to work on the optimisation of riboflavin (vitamin B2) synthesis. In 2003, by which time she was the mother of a small child, Ebert moved from the Roche laboratories to the Institute for Systems Dynamics at the University of Stuttgart where she joined the systems biology research group run by Professor Ernst Gilles. Roche sold its vitamin business to Dutch DSM in the same year. After the birth of her second child, which meant she could only do part-time research, Ebert dropped the idea of doing a habilitation. This was basically due to the German Higher Education Framework Act which made it difficult at the time for women to combine family lives and scientific work.
In 2005, she joined Boehringer Ingelheim in Biberach where she was able to put her previous experience at Roche Vitamins to good use as a specialist for high-throughput screening in process development. At Roche Vitamins, she had primarily focused on enzymes and enzyme purification. Looking back, she regards her involvement in downstream processing as a logical continuation of her previous work.
Focusing on the entire bioprocessing chain at Rentschler
In autumn 2007, Ebert moved on to the biopharmaceutical contract manufacturer Rentschler Biotechnologie in Laupheim where she accepted a job as process manager in DSP (downstream processing) development. She was in charge of technological developments and customer projects. This also meant that she could stay in Baden-Württemberg. In 2009, she was promoted to head of bioprocess engineering.
During her time as the head of Rentschler Biotechnologie's bioprocess engineering division, Ebert developed a depth filter with absorptive properties that made purification faster and cheaper by combining two process steps into one and eliminating an expensive chromatography step. This filter was developed in cooperation with a company called 3M. She also developed ion exchanger models and, as part of BMBF-funded projects, she studied the crystallisation of proteins with regard to scalability and application in biopharmaceutical production. The latter projects were carried out in cooperation with the Department of Pharmaceutical Biotechnology at the Biberach University of Applied Sciences. Ebert's range of tasks was becoming more diverse and she eventually also became involved in upstream development.
Young academics appreciate Ebert
When Ebert found out that Biberach University of Applied Sciences were setting up an industrial biotechnology course with a professorship in process engineering, she applied and, after an evaluation period of around 12 months, was offered the position. Talking to her about why she wanted to return to academia, Ebert points out that she loves working with students. This is probably why she still has a photo on her door of the students that she taught during her time at Rentschler Biotechnologie. She is still in regular contact with most of them.
In focus: more economic production processes
Ebert focuses on two areas of major economic importance. One of these areas is the recovery and purification of proteins and other biological products, a process that is referred to in the pharmaceutical industry as downstream processing. As the downstream processing in the biotechnology and pharmaceutical industry still consumes a large proportion of all manufacturing costs, Ebert is hoping to develop new and cheaper methods and assess their applicability. The second area involves tapping new economic substrate sources in order to make biotechnological production cheaper. In industrial biotechnology, fermentation processes run with expensive broth components. And it goes without saying that this makes biological production a lot less competitive.