Selecting a cGMP Microbial Fermentation CDMO: Key Capabilities & Considerations

Microbial fermentation remains one of the most established platforms for microbial drug substance manufacturing, used to produce recombinant proteins, vaccine antigens, and enzyme therapeutics. Sponsors evaluating a CDMO for microbial fermentation typically look for process development expertise, scalable fermentation capacity, and robust quality systems, the foundation for carrying a program from development through GMP manufacture.

BioCina's Adelaide facility has more than 30 years of E. coli-based microbial fermentation experience and has cloned and expressed 100+ microbial products. The site covers strain onboarding, upstream process development, fermentation, recovery, and purification through to QC testing and QA batch release, with refolding available for programs expressed as inclusion bodies, under a quality system licensed by the Australian TGA and aligned with FDA and EMA expectations.

Capacity constraints, batch-to-batch yield variability, and regulatory scrutiny shape most decisions around microbial biologics manufacturing. Process design plays a critical role in controlling these risks.

It starts before fermentation, at the construct level. BioCina designs multiple variants of the target protein across different vector backbones, solubility tags, affinity tags, and signal peptides, then clones and transforms each construct into the respective E. coli host strains. Multiple clones are screened for each variant and host combination through small-scale shake flask growth and expression studies at 20 to 50 mL, identifying the best-performing clone to carry forward into process development. For programs that call for additional data at this stage, screening can be extended to 1 L fermentation scale.

With a lead clone selected, BioCina applies a Quality by Design (QbD) approach to microbial process development. Fermentation studies at 1 L scale are run in a design of experiments (DoE) format, evaluating critical process parameters such as media composition, induction strategy, fed-batch profile, and dissolved oxygen control to establish robust control strategies for scale-up and GMP manufacture.

Fermentation scale-up carries real technical risk: oxygen transfer, agitation, mixing time, and heat transfer all shift with vessel size. BioCina’s fermentation platform is designed to progressively characterize and align process parameters and control strategies across scales, from development through GMP manufacture, reducing scale-up risk as programs advance.

E. coli fermentation is the foundation of BioCina’s bacterial expression systems, supporting programs across K-12 and B strain backgrounds. The organism has historically been used to produce nearly 30% of approved recombinant therapeutic proteins. [2] Beyond E. coli, the platform supports Streptococcus pneumoniae and Salmonella enterica for vaccine antigen programs, both well-established organisms for whole-cell and antigen-carrier vaccines. [3] Yeast expression systems, including Pichia pastoris and Saccharomyces cerevisiae, are available at development scale for programs where glycosylation or secretion requirements make E. coli a less ideal fit. [4]

Programs with an established expression system do not need to start over. BioCina works directly with client-supplied host strains, cell banks, and expression vectors, building process development around the system the client already has. Before any material is received, the client provides evidence of its identity, purity, and integrity. Host strains and cell banks are checked for viability, purity, and bacteriophage contamination, along with plasmid sequence integrity for recombinant cell lines, while vectors and plasmid constructs are checked against sequence and purity data. This is done either by reviewing the client’s test certificates and reports or by testing samples at external laboratories.

The platform has produced bulk drug substance and intermediates across recombinant proteins, vaccine antigens, growth hormones, enzymes, and antibody fragments, including scFv, diabody, and nanobody formats. It also supports multiepitope and whole-cell recombinant vaccine programs. For example, BioCina has developed a nanobody and a diabody for two different oncology clients.

Microbial fermentation is best suited to proteins that do not need mammalian-style post-translational modification, including those expressed as inclusion bodies. Where a program requires complex glycosylation, a mammalian platform is often a better starting point.

Downstream processing is tailored to the expression system and product, with recovery and purification strategies designed for both soluble intracellular product and inclusion bodies, while controlling process-related impurities such as host cell protein and residual DNA. [5] Continuous cell lysis releases intracellular product from fermentation campaigns up to 500 L, and continuous-flow centrifugation supports cell harvesting and inclusion body recovery. For programs expressed as inclusion bodies, BioCina’s 3,000 L refold tank, the largest protein refolding capacity at any Australian CDMO, supports refolding at scale. Large-diameter chromatography column systems then support scale-up of established purification trains from development through commercial-scale campaigns.

BioCina structures its fermentation platform as a single continuum spanning process development through commercial supply, so a program does not need to change manufacturing partners as the program advances.

CDMOs running fermentation trains across separate facilities, or under separate ownership structures, introduce an inter-site technology transfer step each time a program moves between scales. Keeping development, scale-up, and GMP manufacturing within the same site reduces the need for inter-site transfer and simplifies knowledge continuity as programs progress.

BioCina's Adelaide site holds an active TGA manufacturing licence for clinical and commercial biological drug substance manufacturing, along with a TGA contract testing licence covering biological, chemical, physical, and molecular testing. The site's operating history includes taking a biologic product from clinical development through to commercial-scale manufacturing, and its manufacturing SOPs and quality framework have been successfully inspected by the US FDA with zero observations. BioCina has maintained a record free of critical GMP observations across subsequent inspections.

Australia's GMP framework is based on the PIC/S Guide to GMP, and the TGA also adopts relevant international scientific guidelines while maintaining regulatory cooperation with major international authorities. BioCina's GMP documentation is generated within this internationally aligned framework, supporting programs intended for submission across multiple jurisdictions.

Quality oversight is applied on a phase-appropriate basis, with QC testing and QA batch release before disposition, and method qualification and validation requirements increasing as programs progress toward commercial manufacture. QP batch release is available for EU-bound programs.

Microbial drug substance manufactured in Adelaide transfers to BioCina's sterile fill-finish facility in Perth. A single project management team coordinates the program from fermentation through finished, released drug product. This integrated model simplifies coordination between drug substance and drug product manufacturing, reducing technology-transfer interfaces and handoff risk as programs progress toward commercial supply.

Moving a therapeutic program from drug substance to drug product manufacturing often introduces scheduling delays, technical handoff risk, and regulatory complexity. BioCina reduces multi-vendor friction by managing both stages across our two-site network. By connecting cGMP microbial fermentation in Adelaide directly with sterile drug product fill-finish in Perth, clients get a single accountable partner and a streamlined supply chain from bulk drug substance to finished vial or syringe. The same E. coli fermentation platform also supports plasmid DNA (pDNA) manufacturing, extending that same integrated network to sponsors with pDNA programs in their pipeline.