Let sustained selection deliver the traits that rational design cannot reach — solvent tolerance, low-pH survival, growth on a new feedstock. Part of our Microbial Strain Engineering & Fermentation Optimization Platform.

Tolerance, robustness, and feedstock flexibility are polygenic and poorly mapped. Adaptive evolution reaches them anyway.
Surviving a lignocellulosic hydrolysate, holding productivity at low pH, or growing on a substrate the organism never encountered are traits distributed across dozens of loci. No target list exists to edit, and rational design stalls before it starts. Adaptive Laboratory Evolution sidesteps the problem: apply the pressure the process will apply, keep the population dividing, and let the fittest lineages emerge over hundreds of generations.
Creative BioMart Microbe integrates serial batch, continuous culture, automated, and specialized selection strategies into a unified adaptive evolution platform. Each campaign is assembled from a cultivation mode, a selection pressure, and a monitoring strategy chosen to match your target trait and process conditions.
Campaigns close with whole-genome resequencing of endpoint clones and populations, so you receive not only an improved strain but the mutations behind it. Those variants can then be moved into a clean production background through our Strain Directed Evolution service, or verified against a wider variant set built by Mutant Library Construction.
The result is a strain selected under the conditions it will actually face — and a documented genetic explanation for why it performs.
Every campaign is assembled from a cultivation mode, a selection pressure, and a monitoring strategy. The three choices are made together, because the wrong pairing either kills the population or lets it coast.
Serial Batch Evolution
Cultures are transferred at exponential phase into fresh selective medium, returning the population repeatedly to unrestricted growth. Growth-based transfer timing maintains synchronized physiological states across parallel lineages. Best for: tolerance traits and parallel replicate lineages.
Continuous Culture Evolution
Chemostat, turbidostat, and auxostat operation hold the population under uninterrupted selection at a steady state you define. A chemostat fixes growth rate through the dilution rate and selects on nutrient affinity; a turbidostat lets cells grow at their maximum specific growth rate under steady-state selection; an auxostat ties feed to a measured variable such as pH. Best for: substrate limitation and growth-rate maximization.
Automated Evolution Platforms
Integrated online monitoring tracks culture performance throughout the run, with feedback control adjusting selection pressure to maintain evolutionary momentum. Pressure is modulated based on population response, keeping lineages away from both extinction and stagnation across extended campaigns. Best for: long campaigns and reproducible ramp control.
Specialized Selection Strategies
The pressure itself is the design variable. We apply substrate limitation, product tolerance, temperature, pH, osmotic, oxidative and solvent stress, co-culture evolution, and multi-factor gradients that ramp two or more pressures together. Combining stresses is what separates a strain that survives one laboratory variable from one that holds up in the real fermentation. Best for: industrial robustness under combined conditions.
Mode selection determines what the population is actually competing on. The table below is the starting point for that decision during consultation.
| Mode | Operating Principle | Growth Rate | What It Selects For |
|---|---|---|---|
| Serial batch | Periodic transfer at exponential phase into fresh medium containing the selection pressure | Fluctuating — repeated lag, growth, and depletion | Fastest recovery and growth under the applied stress |
| Chemostat | Continuous feed at a fixed dilution rate; one nutrient held growth-limiting | Fixed by the dilution rate | Highest affinity for the limiting substrate |
| Turbidostat | Feed regulated by optical density feedback; nutrients kept in excess | Maximal and self-selected | Maximum specific growth rate under steady-state selection |
| Auxostat | Feed controlled by a measured culture variable such as pH or dissolved oxygen | Set by the controlled variable | Adaptation to a defined physiological set point |
| Pressure | How It Is Applied | Target Trait |
|---|---|---|
| Substrate limitation | Growth-limiting feed of the target carbon or nitrogen source in continuous culture | Uptake affinity, non-native substrate utilization |
| Product tolerance | Stepwise increase of the accumulating product in the medium | Higher end titer, reduced product inhibition |
| Temperature stress | Gradual ramp above or below the growth optimum across successive passages | Thermotolerance, reduced cooling demand at scale |
| pH stress | Progressive acidification or alkalization under buffered or auxostat control | Low-pH organic acid production, acid-resistant probiotics |
| Osmotic stress | High sugar or salt loading raised in defined increments | High-gravity fermentation, dehydration survival |
| Oxidative stress | Controlled peroxide exposure or elevated dissolved oxygen | Redox robustness, aerobic process stability |
| Solvent tolerance | Rising concentrations of alcohols, organic solvents, or hydrolysate inhibitors | Biofuel and biorefinery robustness |
| Co-culture evolution | Paired or consortium cultivation with a partner organism | Cross-feeding, community stability, syntrophic productivity |
| Multi-factor stress gradient | Two or more pressures ramped simultaneously across the campaign | Combined robustness under real process conditions |
Six stages, from initial consultation to delivering the adapted clone with its mutation list.
Consultation & Scoping
Define target trait and pressure
Baseline Phenotyping
Find the current tolerance ceiling
Campaign Design
Mode, ramp profile, replicates
Evolution Run
Monitored passaging or continuous run
Isolation & Validation
Clone picking, stability testing
Characterization & Delivery
Mutation report + stocks
01 · Platform Capability
02 · Typical Campaign Metrics
| Campaign duration | 4–16 weeks, pressure-dependent |
| Generations accumulated | 100–1,000+ |
| Parallel lineages | 3–8 per condition |
| Endpoint clones characterized | 5–20 per lineage |
| Host coverage | Bacteria, yeast, fungi, microalgae |
03 · Deliverables & Documentation
| Adapted strain | Glycerol stocks of endpoint clones |
| Population archive | Frozen intermediate passages |
| Phenotype report | Growth, tolerance ceiling, productivity |
| Mutation report | Variant list with frequencies |
| Campaign record | Mode, ramp profile, monitoring traces |
An evolution campaign is only as good as its starting point. Alongside the culture, we need to know where your strain currently stops performing.
| Required | Optional | Not Accepted |
|---|---|---|
|
|
|
| Growth curve in your reference medium | Sets the unstressed control and doubling time |
| Inhibitory concentration of the target stress | Defines where the ramp begins |
| Parent genome sequence | Separates evolved mutations from pre-existing variants |
| Product or reporter assay | Tracks productivity alongside growth |
| Process medium sample | Allows evolution under the actual downstream condition |
Storage & Shipping: Ship glycerol stocks on dry ice, or send stabilized agar slants at ambient temperature with cushioning. Send at least two independent vials so a campaign can be restarted without a second shipment, and avoid temperature excursions that reduce viability before the run begins. If a hydrolysate or process medium is supplied, ship it separately and note any preservative added. Contact our team via the contact form before dispatch for biosafety clearance.
No Target List Required
Polygenic traits such as tolerance and feedstock flexibility are reached through selection, so a campaign can start before anyone knows which genes are involved.
All Four Cultivation Modes
Serial batch, chemostat, turbidostat, and auxostat operation run on the same platform, so the mode follows the trait rather than the equipment on hand.
Pressure Matched To Your Process
Campaigns can be run in your own hydrolysate or process medium, so the strain adapts to the conditions it will meet downstream instead of a simplified laboratory proxy.
Ramping That Responds To The Culture
Stress levels are adjusted from live monitoring data rather than a fixed calendar, keeping lineages between the two ways campaigns fail — extinction and stagnation.
Replicate Lineages, Not Single Winners
Running several lineages in parallel shows whether an adaptation is reproducible, and mutations recurring across independent lines are the ones worth transferring.
Mutations Mapped, Not Just Strains
Endpoint resequencing and optional reverse engineering identify the causal variants, turning an evolved isolate into a defined edit you can reapply to other backgrounds.
"We sent our own hydrolysate along with the strain, and the campaign was run in that medium rather than a synthetic substitute. The adapted isolate performed on the first attempt in our pilot fermentation, which almost never happens."
Dr. E. L.
Bioprocess Engineer
USA
"The chemostat campaign on a limiting carbon source gave us the uptake improvement we had failed to engineer for two years. Being able to read the dilution-rate history alongside the sequencing data made the result easy to defend internally."
Dr. T. N.
Metabolic Engineer
USA
"Six parallel lineages under the same solvent ramp told us far more than a single line would have. Two independent lineages converged on the same locus, and that convergence is what convinced us to build the edit into our production host."
Dr. C. A.
Synthetic Biologist
USA
"Our previous attempt at adaptive evolution died out twice because the stress steps were too aggressive. Here the ramp was driven by the growth signal, and the culture stayed viable through the entire ascent."
Dr. N. H.
Principal Scientist
USA
"Combining thermal and osmotic pressure in one gradient produced a starter culture that holds up in high-gravity conditions. Testing the two stresses separately had never reproduced that behavior."
Dr. M. B.
Fermentation Specialist
Germany
"The frozen archive of intermediate passages turned out to be the most useful deliverable. When we wanted to understand when the phenotype appeared, we could go back and re-test the population at each stage."
Dr. A. V.
Research Director
USA
Lignocellulosic Biorefining
Furfural, HMF, acetate tolerance
Organic Acids
Low-pH titer and survival
Biofuels & Solvents
Alcohol and solvent tolerance
Non-Native Substrates
Methanol, glycerol, xylose uptake
Probiotics & Starters
Acid, bile, drying survival
High-Gravity Fermentation
Osmotic and thermal load
An oxidation-deficient derivative of Pseudomonas taiwanensis VLB120 was evolved under HMF selection pressure using robotics-assisted adaptive laboratory evolution. Passaging was automated in microtiter-scale cultures and triggered whenever scattered-light intensity crossed a fixed threshold, giving seven serial passages across roughly one week and about 40 generations. Final cultures reached the transfer threshold in a mean of 14.7 h, more than twice as fast as the starting cultures, and isolated clones grew in the presence of 8 mM HMF where the unevolved parent did not grow at all. Whole-genome sequencing found loss-of-function mutations in the transcriptional regulator mexT in every evolved clone, and reverse engineering of mexT variants reproduced the tolerance, tracing the benefit to shutdown of the mexEF-oprN efflux pump. The study shows how automated passaging, online growth monitoring, and endpoint resequencing turn a short campaign into a causally explained trait.

A thermotolerant Candida tropicalis isolate was put through repetitive long-term cultivation with a gradual temperature increase in medium containing 200 g/L glucose, so heat and osmotic load acted together. Seven-day passages carried the culture from 40°C up to 44.5°C, and the single surviving lineage yielded the adapted strain X-17.2b. Fermenting 160 g/L glucose at 37°C, the adapted strain reached 60.7 g/L ethanol against 46.5 g/L for the parent — a 30.7% gain accompanied by 15.6% higher glucose consumption — and it still produced 27.8 g/L at 42°C where the parent managed 14.9 g/L. Tolerance to ethanol, furfural, and HMF improved as well. This is the multi-factor stress gradient strategy in practice: stacking two industrially relevant pressures in one campaign yields a strain fit for the process rather than for a single laboratory variable.

Turn Evolved Mutations Into Defined Edits
Variants recovered from a campaign can be rebuilt in a clean production background through directed evolution and targeted engineering, so the gain travels with the strain.
Serial batch suits tolerance traits and stress ramps because the population repeatedly re-enters exponential growth. A chemostat is the right choice when the goal is affinity for a limiting substrate, a turbidostat when you want maximum specific growth rate under steady-state selection, and an auxostat when selection should track a controlled variable such as pH. We confirm the mode after baseline phenotyping.
Stress is raised in steps rather than set at a target value from the outset, and each step is gated on the measured growth response. If a lineage slows beyond a defined margin, the pressure is held or reduced until growth recovers. Parallel lineages provide additional insurance, since losing one line does not end the campaign.
Most campaigns run 4–16 weeks and accumulate 100–1,000 or more generations, depending on doubling time and how steeply the pressure rises. Short automated campaigns can produce measurable tolerance gains in a week when the selection is strong, while substrate-affinity work in continuous culture generally needs longer.
Endpoint clones are isolated, passaged without the selection pressure, and re-tested to confirm the phenotype persists. Whole-genome resequencing then identifies the underlying mutations, and candidate variants can be reverse engineered into the parent background to demonstrate that they alone reproduce the trait.
Yes, and it usually gives a better outcome than a synthetic proxy. Real hydrolysates and process media contain inhibitor mixtures that no single-compound challenge reproduces. Send a representative sample with the culture and note any preservative, and we will characterize it before designing the ramp.
They can, through multi-factor stress gradient evolution. Two or more pressures — for example temperature together with high sugar loading — are ramped in parallel so the population adapts to the combination. Strains selected this way often outperform strains evolved against each stress separately when placed in a real fermentation.
The mutation report is the bridge to the rest of the platform. Causal variants can be rebuilt in a clean host through our Strain Directed Evolution service, explored more broadly with Mutant Library Construction, or ranked across many isolates by High-Throughput Screening.
Tell us the condition where your strain currently stops performing—our team will design the cultivation mode, the stress ramp, and the readout around it.
Diversity generation
Million-scale discovery
Iterative enhancement
Industrial robustness
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