Your fermentation works in the flask. We make it work at scale.

Yes. Confidentiality is the starting point of every project at Deltra Labs, not an afterthought. We sign a mutual non-disclosure agreement before any technical discussion begins — this includes before you share strain identity, fermentation data, process parameters, or any business context. If you prefer to have an NDA in place before even the first exploratory call, that is not a problem. We sign first, then talk.  All results, process data, fermentation protocols, analytical data, and intellectual property generated during your project are fully and exclusively yours. Deltra Labs retains no rights, licences, or claims to any project output. Your organisms are handled in dedicated containment that is kept physically separate from other client work. All project correspondence, data files, and deliverables are stored securely and are never shared with third parties.  Upon project completion, all biological material belonging to you — production strains, seed cultures, intermediate samples — is returned, transferred to a storage facility of your choice, or destroyed according to your written instructions. The mutual NDA remains in force for the full term agreed in the contract, typically five years from project close. For clients working in sensitive sectors such as speciality chemicals, pharmaceuticals, or food ingredients, we are experienced in working under the confidentiality standards those industries require.

We run fermentation development and optimisation up to 10 L on site, which covers the full range of laboratory and small pilot-scale work needed to develop a robust, documented bioprocess. This includes shake flask screening, bench-top bioreactor runs from 1 L to 10 L, fed-batch strategy development, media optimisation using design of experiments, and process parameter studies for pH, dissolved oxygen, temperature, and feeding profiles.  For campaigns at larger scale — typically 50 L to 300 L and beyond — we coordinate with trusted partner facilities and act as your single point of contact throughout. This means you do not need a separate commercial relationship with a pilot plant, and the process knowledge and documentation built during the in-house development phase is transferred directly without information loss. We attend the first scale-up runs at partner facilities when needed and provide on-site technical support during the transfer.  The deliverable for any scale-up phase is a complete scale-up transfer package: a fully documented process protocol with all critical parameters and their acceptable ranges, media formulation and preparation instructions, inoculation procedure, feeding strategy, monitoring and control logic, and a summary of scale-up considerations specific to your organism and product — including oxygen transfer, mixing, foam control, and heat removal. The goal is that a competent fermentation team at any receiving facility can run the process successfully from the documentation alone.

Yes, and we actively prefer it. Existing data — even incomplete or preliminary data — tells us what has already been tried, what works, and where the current bottlenecks are. That context saves time and prevents us from repeating work you have already done.  We regularly start from a wide range of starting points. Some clients arrive with a fully documented shake-flask protocol and clean baseline performance data, ready to move directly into bioreactor development. Others have early exploratory fermentation results from a few experimental conditions, a rough understanding of the optimal pH and temperature range, and a target titer they want to reach. Others come with only a production strain and a target compound, no fermentation data at all, and need the process to be built entirely from scratch. All of these are valid starting points.  If you have existing data, send it ahead of the intro call. We will review it beforehand so the call is focused on what matters — the gap between where you are now and where you need to be — rather than on background that can be covered in writing. If you have no existing process data at all, we start with strain characterisation and basic growth studies to establish the biological baseline before any optimisation work begins.  The intro call is the right place to align on the best starting point for your specific situation. There is no minimum amount of data required to reach out.

Every fermentation process development project at Deltra Labs starts from first principles, the underlying physics and physics that govern how a microorganism converts a carbon source into biomass, a target product, or both. Understanding these principles at the start of a project is what determines whether the final process is robust, scalable, and economically viable, or whether it works on a good day in the flask and fails under real production conditions.Starting from physical and biological first principlesAt its most fundamental level, fermentation is the conversion of a carbon source — glucose, sucrose, molasses, glycerol, methanol, CO2 or a more complex substrate — into microbial biomass and, in many cases, a target compound. The rate and efficiency of this conversion is governed by the interplay between the organism's metabolic capacity, the availability of nutrients and oxygen, the physical environment of the bioreactor, and the inhibitory or stimulatory effects of the product itself. Process development at Deltra Labs begins by mapping these interactions for the specific organism and product combination before any optimisation experiments are designed.Aerobic processes — biomass, growth rate, and oxygen transferFor aerobic fermentation processes, growth rate and oxygen transfer rate are typically the two primary limiting factors that define the operating envelope of the process. Oxygen is sparingly soluble in fermentation broth — approximately 7 to 8 mg/L at 30°C under atmospheric pressure — and is consumed rapidly by actively growing aerobic microorganisms. When oxygen demand exceeds the oxygen transfer capacity of the bioreactor, dissolved oxygen drops, metabolism shifts, unwanted byproducts accumulate, and yield collapses. Designing a fermentation process that reliably delivers sufficient oxygen to the culture across the full growth trajectory — from inoculation through the exponential phase to the production or harvest phase — is one of the central engineering challenges in aerobic bioprocess development.This is particularly relevant for biomass production processes, where the target product is the cell mass itself — as in the production of single-cell protein, baker's yeast, probiotic organisms, or microbial inoculants for agricultural applications. In these processes, maximising the specific growth rate while maintaining adequate dissolved oxygen, avoiding overflow metabolism, and minimising the heat generated by rapid growth are the dominant process design objectives. Alternatively, fed-batch operation with controlled substrate feeding is also important in many processes to avoid substrate inhibition or the Crabtree effect in organisms such as yeast that produce ethanol aerobically when glucose concentrations are high. The oxygen transfer rate, characterised by the volumetric mass transfer coefficient kLa, must be matched to the oxygen uptake rate of the culture at each stage of the fermentation. Agitation speed, aeration rate, bioreactor geometry, and broth rheology — which is significantly affected by cell density and, in the case of filamentous fungi, by the morphology of the mycelium — all influence kLa and must be considered together when developing the aeration and feed strategy.For biomass-directed aerobic processes, the economic value of the product is typically lower per kilogram than for speciality fermentation products. This means that process economics are strongly driven by volumetric productivity — how much product is produced per litre of bioreactor volume per hour — and by the efficiency of the downstream processing train. A high biomass titer in the bioreactor is only economically useful if the downstream separation, concentration, and drying steps can process it efficiently and at acceptable cost. For this reason, we consider downstream processing implications — broth filterability, centrifugation behaviour, and product stability — during the upstream development phase rather than treating them as a separate downstream problem.Secondary metabolite processes — shifting from growth to productionWhen the target product is a secondary metabolite rather than biomass, the process logic changes fundamentally. Secondary metabolites are compounds that microorganisms produce not for growth but in response to specific physiological states, often triggered by nutrient limitation or environmental stress. Designing a fermentation process for secondary metabolite production therefore means designing a process that first grows the organism efficiently to the desired cell density and then deliberately triggers the metabolic shift from growth to production.The nature of the trigger depends on the product and the organism. For oleaginous yeasts and algae producing lipids, fats, and single-cell oils, nitrogen limitation is the classical induction strategy — when the nitrogen source is depleted while carbon is still available, carbon flux is redirected from biosynthesis of new cellular material into triacylglycerol accumulation. Yarrowia lipolytica, Lipomyces starkeyi, Rhodotorula species, and oleaginous Chlorella strains all respond to nitrogen limitation with significantly elevated lipid titres, and the ratio of carbon to nitrogen in the medium at the point of limitation is one of the most critical process parameters to optimise. For auxotrophic cultivated microalgae specifically, light availability and light penetration through the culture — both of which decrease as cell density increases — add an additional dimension to the process that is not present in heterotrophic fermentation.For other secondary metabolites — polyketides, non-ribosomal peptides, organic acids, pigments, vitamins, biosurfactants, and many enzyme products — mineral limitation or specific precursor limitation is often the relevant trigger. Phosphate limitation is used in several antibiotic and secondary metabolite fermentations. Magnesium, iron, manganese, and zinc concentrations are known to regulate secondary metabolism in a range of filamentous fungi and actinomycetes, including Streptomyces species producing antibiotics and other bioactive compounds. The specific mineral that acts as the regulatory signal varies by organism and pathway, and identifying the relevant limitation as part of the process development programme is part of the work Deltra Labs does during the scoping and development phases.Fed-batch strategy is central to secondary metabolite process design. The carbon feed rate must be calibrated to maintain the desired physiological state — typically a specific growth rate below the maximum, combined with the relevant nutrient limitation — while avoiding carbon starvation on one hand and overflow metabolism and byproduct accumulation on the other. Developing a reliable fed-batch profile, whether based on a fixed feeding schedule, an exponential feed, or a feedback-controlled strategy based on dissolved oxygen or carbon dioxide evolution rate, is typically one of the core deliverables of a secondary metabolite process development project.Anaerobic fermentation — product inhibition and toleranceAnaerobic fermentation processes operate without oxygen and are used for a range of industrially important products including ethanol, lactic acid, acetic acid, butyric acid, succinic acid, butanol, and a range of other organic acids and solvents. The defining challenge of anaerobic fermentation that distinguishes it from aerobic processes is product inhibition — the phenomenon whereby the product itself becomes toxic to the producing organism at concentrations that are often well below the economically target concentration.Ethanol inhibition in Saccharomyces cerevisiae is the classic example — at concentrations above approximately 10 to 12% v/v, ethanol disrupts membrane integrity, reduces enzyme activity, and ultimately arrests fermentation before the available sugar is consumed. Industrial bioethanol strains have been selected and improved over decades to push this tolerance threshold higher. Lactic acid inhibition in lactic acid bacteria operates through a combination of product toxicity and pH drop — as lactic acid accumulates and pH falls, growth and production rates decrease significantly, which is why industrial lactic acid fermentations are typically run with pH control through base addition to maintain productivity. Butyric acid, acetic acid, and similar short-chain fatty acids are inhibitory at even lower concentrations and present significant process development challenges for the organisms that produce them.Dealing with product inhibition in anaerobic fermentation process development involves several strategies that Deltra Labs evaluates depending on the organism and product. These include strain-level tolerance improvement through classical mutagenesis or adaptive laboratory evolution — selecting for variants that maintain productivity at higher product concentrations — as well as process-level strategies such as continuous removal of the inhibitory product through in-situ product recovery, or integrated membrane separation. The mass balance of the anaerobic process — the stoichiometric relationship between substrate consumed, product formed, and carbon dioxide or hydrogen released — also constrains the theoretical maximum yield and must be understood before realistic productivity targets can be set.How this translates into a project at Deltra LabsFor any new fermentation development project, the starting point is a characterisation phase in which we establish the biological baseline of the organism under defined conditions — growth kinetics, oxygen uptake rate, substrate consumption rate, and initial product formation profile. This data defines the physiological operating window for the process and informs the design of the fed-batch strategy, the oxygen transfer requirements, and the nutrient limitation approach if secondary metabolite production is the goal. The process is then developed iteratively in controlled bioreactor experiments, with each experiment designed to answer a specific question about the process rather than to screen conditions exhaustively. Go/no-go milestones are built into the project structure so that the decision to continue, adjust the strategy, or close the project is always based on data rather than optimism.

New enquiries are replied to within one working day. An intro call can typically be scheduled within a few days of first contact. The scoped project proposal is prepared after the intro call, usually within five to seven working days depending on the complexity of the project scope.  Lab work starts as soon as the project agreement is signed and any required biological material has been received and quarantine-cleared. For standard production organisms — E. coli, Corynebacterium, Saccharomyces cerevisiae, Aspergillus species, and similar well-characterised hosts — quarantine and initial characterisation typically takes one to two weeks. For novel or less-characterised organisms, this phase may be longer depending on the available literature and the biological behaviour of the strain.  For projects with a defined external deadline — a pilot campaign with a fixed date, a regulatory submission timeline, or a customer sampling commitment — contact us directly by email or phone and describe the constraint. We will give you an honest assessment of whether the timeline is achievable before the formal process begins. We do not take on projects where we believe the timeline is not realistic, because delivering incomplete or rushed results is not in your interest or ours.  The fastest route to getting started is a clear, concise first message describing your organism, your current process status, and your target outcome. That gives us enough context to prepare for the intro call and makes the first conversation substantially more productive.

Yes. Working with organisms outside the standard industrial production hosts is something we actively seek out and are well-equipped to handle. Novel isolates, organisms with limited published literature, no established fermentation protocol, and no characterised biosynthetic pathway for the target product — require a different starting approach than working with well-studied hosts such as E. coli or Saccharomyces cerevisiae, and that exploratory phase is work we find genuinely interesting.  The starting point for a novel organism project is always biological characterisation: growth kinetics across a range of pH, temperature, and dissolved oxygen conditions; carbon and nitrogen source utilisation; tolerance to relevant process stresses; and preliminary product formation under uncontrolled conditions. This characterisation phase provides the biological foundation for rational process development and gives us the data needed to design the first controlled bioreactor experiments.  We have worked with uninvestigated bacterial isolates from soil and industrial environments, wild-type yeast strains with unusual substrate utilisation profiles, and filamentous fungi producing novel secondary metabolites with no published fermentation data. In each case the process is the same: characterise first, then develop.  If you are not sure whether your organism or concept is suitable for a fermentation development project — either because the biology is uncertain, the target compound has not been produced at any scale, or because you are not sure whether the titre levels you are seeing in preliminary experiments are sufficient to justify a development programme — the intro call is the right place to discuss it. We will give you a straightforward assessment of feasibility and an honest view of the risks and unknowns before any commitment is made.

Fermentation development refers to building a production process from scratch, establishing the bioreactor protocol, media composition, feeding strategy, oxygen transfer strategy, and operating parameters for a strain that has no existing bioprocess beyond shake-flask culture. It is a longer and more exploratory process that typically begins with organism characterisation and ends with a documented, transferable and scalable bioreactor protocol. Fermentation optimisation starts from an existing process that already works at bioreactor scale and improves specific performance indicators - titer, volumetric productivity, oxygen transfer efficiency, media cost, batch-to-batch consistency, or downstream processing compatibility. Optimisation is typically faster and more targeted than development because the process framework already exists and the work focuses on specific bottlenecks. Deltra Labs works on both, and many projects combine elements of both — for example, developing the fermentation mode from batch to fed-batch as part of an optimisation campaign.

We develop and optimise fermentation processes for bacteria including E. coli, Bacillus subtilis, Corynebacterium glutamicum, Streptomyces species, and lactic acid bacteria. For yeasts, we work with Saccharomyces cerevisiae, Pichia pastoris (Komagataella phaffii), Yarrowia lipolytica, Kluyveromyces marxianus, and related species. For filamentous fungi, we work with Aspergillus, Penicillium, Trichoderma, and Rhizopus species. We also work with novel and uninvestigated isolates on a case-by-case basis. If you are working with an organism not listed here, contact us — we evaluate each case individually and will give you an honest assessment of feasibility during the intro call.

We work with batch, fed-batch, repeated batch fermentation and continuous fermentation formats. Fed-batch is the most commonly used mode for industrial production processes and forms the core of most of our development projects. We design feeding strategies based on the specific metabolic demands of the organism and the kinetics of the target product — including growth-coupled production, non-growth-associated production, and two-stage strategies where biomass accumulation and production are separated. We use design of experiments (DoE) approaches to systematically explore and optimise media composition, feeding profiles, and process parameters, which allows us to identify the critical variables efficiently without running an excessive number of experiments.

A scale-up transfer package is the complete set of documentation needed for another facility — a contract manufacturer, pilot plant, or internal production site — to reproduce your fermentation process at larger scale without loss of performance. It includes the optimised bioreactor process protocol with all operating parameters and their acceptable ranges; the media formulation with all component concentrations, and preparation instructions; the inoculation procedure from frozen stock through seed culture to production bioreactor; the feeding strategy including feed composition, timing, and control logic; the monitoring and control strategy including critical process parameters, alarm limits, and intervention criteria; a summary of scale-up considerations including oxygen transfer, mixing, foam control, and heat removal; and a summary of the development history so the receiving team understands the rationale behind key process decisions. The goal is that a competent fermentation team at the receiving facility can run the process successfully without requiring Deltra Labs on-site, though we offer optional transfer support and can attend the first scale-up runs if needed.

Yes. Fermentation troubleshooting is a standalone service at Deltra Labs and one of the most common reasons clients contact us. Processes stop performing as expected for a variety of reasons, changes in raw material quality or supplier, contamination events, strain drift after extended propagation, equipment changes such as a new bioreactor vessel or sensor type, changes in water quality, or gradual shifts in process conditions that individually seem minor but collectively affect performance. We approach troubleshooting systematically: reviewing your historical performance data to identify exactly when and where performance diverged from baseline, forming specific hypotheses about probable causes, designing targeted experiments to test those hypotheses, and implementing and validating solutions. We work with your existing data and your existing process — we do not require you to start over.

Yes. Downstream processing, the recovery, clarification, extraction, and purification of the target product from the fermentation broth, is available as a standalone service or as part of an integrated bioprocess development project. We take an integrated upstream-downstream view as a matter of principle, because fermentation and recovery are not independent processes and the overall mass balance is considered important.Decisions made during fermentation development — broth viscosity, cell density, product localisation (intracellular versus extracellular), pH, and osmolarity — directly affect the difficulty and cost of downstream processing. A fermentation process optimised solely for titer at the bioreactor stage can create significant problems in the recovery train that eliminate the economic benefit of the titer gain. By considering downstream implications during upstream development, we help clients avoid this common and costly mistake.The downstream processing unit operations we work with cover the full recovery train from fermentation broth to concentrated or partially purified product. For biomass separation, we work with centrifugation, decanting, and (cross-flow) filtration — the choice between them depends on the organism morphology, broth rheology, and the target product's location. Filamentous fungi and mycelial organisms, for example, require different separation strategies than bacterial or yeast fermentation broths due to the viscosity and filterability of the biomass.For intracellular products — enzymes, pigments, lipids, or other compounds retained within the cell — cell disruption is required before recovery can begin. We have experience with bead milling including dyno milling, high-pressure homogenisation, and enzymatic lysis, and we select the disruption method based on the robustness of the target molecule, the required throughput, and the downstream purification steps that follow. Cell disruption conditions significantly affect product yield and quality and are optimised as an integral part of the recovery process.Product concentration and initial purification steps we work with include cross-flow filtration and ultrafiltration for enzyme concentration and buffer exchange, precipitation strategies for proteins and organic acids, liquid-liquid extraction for hydrophobic compounds, and adsorption-based methods for selective recovery. For enzyme products specifically, we develop concentration and stabilisation protocols that maintain activity through the recovery process and meet the titre and purity specifications required for the intended application.The scope of downstream processing support is defined during the project proposal phase. For clients who need a complete integrated process — from bioreactor to concentrated, characterised product — we scope the upstream and downstream phases together and design them to work as a single system. For clients who already have a working recovery process and need only upstream development, we take the existing downstream constraints into account when optimising the fermentation. And for clients who have a working fermentation and need only the recovery process developed or improved, downstream processing is available as a standalone engagement.