Cirsium Biosciences is creating the next generation of manufacturing technologies for viral vector production. Our novel plant-based platform solves the existing problems of speed, flexibility, scalability, and safety in viral vector manufacturing while dramatically reducing production costs. Our goal is to enable global and equitable access to life-changing genetic therapies.

Position Overview

We are seeking a Fermentation Specialist with hands-on expertise in the cultivation and scale-up of Agrobacterium tumefaciens for use in plant-based biologics production via agroinfiltration. The ideal candidate will have experience in bioreactor/ fermentation process development and scale-up using both shake flasks and bioreactor systems, within regulated environments such as GLP and/or GMP.

This role will be critical to the upstream production of bacterial cultures used in whole-plant agroinfiltration platforms for the expression of therapeutic high-value biologics including AAVs.

Key responsibilities

• Design, execute, and optimize fermentation processes for Agrobacterium tumefaciens and/or related Gram-negative bacterial species.

• Prepare and maintain seed stocks, perform inoculations, and manage fermentations in shake flasks and bench-to-pilot scale bioreactors.

• Monitor and control key fermentation parameters (e.g., pH, DO, temperature, agitation, feed strategy) to ensure culture health and target biomass/YOD.

• Support the upstream process team and the downstream purification team, as necessary.

• Contribute to process transfer, scale-up, and documentation for GMP-readiness, working closely with quality and regulatory teams.

• Maintain accurate and timely records of experiments, batch records, and SOPs in accordance with GLP/GMP expectations.

• Participate in troubleshooting and root cause analysis for process deviations or batch failures.

• Collaborate cross-functionally with molecular biology, plant biology, and manufacturing teams.

Qualifications

• Bachelor’s/Master’s degree in Microbiology, Biotechnology, Chemical Engineering, or a related life science field.
• 3–5 years of industry experience in bacterial fermentation process development or manufacturing biologics.
• Experience working with Agrobacterium tumefaciens.
• Candidates with relevant experience with Bioreactors using mammalian and/or insect cells may be considered.
• Familiarity with plant-based biologics production platforms, especially agroinfiltration, is highly desirable.
• Experience operating bioreactor systems (e.g., Distek, Sartorius, Eppendorf) and associated software.
• Working knowledge of aseptic technique, microbial physiology, and bioanalytics (OD600, plating, CFU/mL, etc.).
• General experience of upstream and downstream workflow and optimization related to the production of a biologic in plants/mammalian/yeast/insect cells is highly desirable.
• Experience in GLP and/or GMP-compliant environments is strongly preferred.
• Detail-oriented with strong problem-solving and organizational skills.
• Ability to manage multiple tasks and prioritize effectively in a fast-paced environment.
• Strong communication skills and ability to work in a collaborative, multidisciplinary team.
• Self-motivated and capable of working independently when needed.