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Condition-aware microbial kinetics

Species Doubling Reference

Peer-reviewed starter, probiotic, and benchmark growth data for dairy and lab contexts

Literature mono-culture benchmarks. Not food safety advice, not a release criterion, and not a mixed-culture rate. These doubling times are single-organism values measured under the conditions each paper cites. Real ferments run mixed, and protocooperation between starter pairs can beat these numbers substantially. Use at your own risk. Open for the full scope limits.

Reference scope

This page summarizes literature-reported microbial growth kinetics for comparison and educational use. Real doubling behaviour varies with strain lineage, inoculum age, oxygen handling, medium composition, pH control, buffering, milk treatment and measurement method.

Monoculture reference only

The displayed td values are mono-culture or single-organism benchmarks under the cited conditions. They should not be treated as direct mixed-culture, cofermentation or symbiotic growth rates.

Cofermentation caveat. Protocooperation and cofermentation can yield effective doubling behaviour far shorter than the mono-culture values shown here, especially for starter pairs such as S. thermophilus and L. bulgaricus. A comparison chart built from independent mono-culture curves is a back-of-the-envelope overlay, not a model of what happens in a vat.

Not food safety advice

This is not a pathogen-safety model, HACCP tool, fermentation process validation, compliance reference, or substitute for direct pH, temperature, CFU or contamination testing.

Not a release criterion. Do not use this reference by itself to clear product for consumption, sale, labeling, patient use, or manufacturing decisions.

Never use this for

  • Clearing a batch, releasing product, or any decision about whether something is safe to eat, drink or administer.
  • Shelf-life determination, product claims or labelling.
  • HACCP plans, process validation or a scheduled process.
  • Predicting the behaviour of a mixed starter, a wild ferment, or any culture you have not characterised.
  • Clinical, probiotic or regulatory submissions.
  • Substituting for measurement. A doubling time from a paper is not a plate count of your vessel.

Verify independently

Check the cited papers, validate conditions against your actual substrate, strain and culture mix, and use qualified food-safety, microbiology or production guidance before using any value for safety-critical, commercial, clinical or regulatory decisions.

No warranty. No liability. No suitability claim. You assume all risk. The tool is provided as-is and as-available, without warranty of accuracy, completeness, merchantability, fitness for a particular purpose, food-safety suitability, or regulatory acceptability. To the maximum extent permitted by law, the author accepts no liability for any loss, injury, illness, damage, cost or claim arising from use of or reliance on this page, and the author and maintainers expressly disclaim responsibility for contamination events, spoiled batches, failed ferments, incorrect strain assumptions, product claims, shelf-life decisions, process release decisions, compliance failures, commercial losses, downstream damages, or any other consequence arising from use or misuse of this page.

No professional relationship. Using this page does not create any professional, advisory or food-safety relationship, and nothing on it is food-safety, microbiological, regulatory or professional advice.

Independent verification required. Check every value against the cited paper and against measurement of your own culture before acting on it. The primary literature, your own measurements and qualified professional judgement control; where this page disagrees with them, this page is wrong.

Consequential damages excluded. To the maximum extent permitted by law, in no event will the author or maintainers be liable for any direct, indirect, incidental, special, exemplary, punitive or consequential damages, including contamination events, spoiled batches, illness, recalls, regulatory exposure, or loss of use, data, profits or business interruption, however caused and on any theory of liability, whether in contract, strict liability or tort including negligence, arising out of or in connection with this page, even if advised of the possibility of such damage.

Indemnity. By using this page you agree to indemnify and hold harmless the author and maintainers against any claim, demand, loss or expense arising out of your use of it or of anything derived from it.

Severability. If any part of this notice is held unenforceable, the remainder continues to apply, and the unenforceable part is limited to the least extent necessary rather than struck out.

Bacterial Growth Database

Doubling times shown here are exponential-phase monoculture reference values. They vary with strain, substrate, oxygen, pH control, and buffering, so each card includes the reported temperature or medium-specific conditions when the paper provides them. Mixed-culture or cofermentation behavior can be materially faster than the values shown here and should not be inferred from these rows.

Entries 12 species
Scope Dairy + lab
Primary years 2000-2023

Compare Up To Six Species

Select one reported mono-culture td behavior per species. The chart normalizes all selections to the same starting abundance, plots doublings over custom time, and estimates a normalized endpoint share from independent mono-culture growth only. It is a back-of-the-envelope overlay, not a cofermentation model.

Mono-culture benchmarks overlaid, not a cofermentation model. Each curve is a single organism under one paper's conditions. Protocooperation between starter pairs such as S. thermophilus and L. bulgaricus can beat these values substantially, so this chart is a back-of-the-envelope comparison and never a release criterion.

Live update. Enter a positive duration to refresh the plot and normalized endpoint share.

Selected species 0
Fastest td n/a
Largest normalized share n/a
Temperature spread n/a

Doubling Behavior Plot

Y-axis shows doublings from the same normalized starting point. Fold change is 2doublings.

Species doubling comparison chart Normalized comparison of selected species doubling behaviors over time.

Normalized Endpoint Share

Percentages below rescale each row's independent mono-culture endpoint from the same starting abundance. They are useful for quick endpoint comparison only and are not mixed-culture composition predictions.

Primary Yogurt Starters

Fast acidifiers and proteolytic partners used to drive classic yogurt fermentation.

S. thermophilus

Streptococcus thermophilus

Starter

Fast thermophilic starter that scavenges oxygen and produces metabolites that help its symbiotic partner acidify milk.

td (model)
~15-24 min
log10 μopt
1.23 +/- 0.09 h-1
Topt
~41°C
Reference medium
Whey + yeast extract

Reported conditions

  • 36°C, pH 5.7: log10 μmax 0.759 h-1, derived td ~23.8 min
  • 40°C, pH 6.5: log10 μmax 1.186-1.247 h-1, derived td ~14.5-15.2 min
  • 44°C, pH 7.3: log10 μmax 1.087 h-1, derived td ~16.6 min

Sources

L. bulgaricus

Lactobacillus delbrueckii subsp. bulgaricus

Starter

Proteolytic thermophile that supplies peptides and drives acidification after S. thermophilus establishes the fermentation.

td
40-75 min (mean ~60)
log10 μopt
1.25 +/- 0.08 h-1
Topt
43.5°C
Reference context
MPL lactose medium / whey models

Reported conditions

  • 42°C, MPL chemically defined lactose medium: td ~60 min; 40-75 min across 22 strains
  • 44°C, pH 5.7: log10 μmax 1.013-1.330 h-1, derived td ~13.6-17.8 min
  • 48°C, pH 4.9: log10 μmax 1.024 h-1, derived td ~17.6 min

Sources

Probiotic Adjunct Cultures

Supplemental cultures used for survival, labeling, and functionality rather than sheer acidification speed.

L. acidophilus

Lactobacillus acidophilus

Probiotic

Common adjunct probiotic that grows slowly in milk during product manufacture, making it a supplemental culture rather than a primary acidification driver.

td (milk, early)
~4.6 h
td (milk, late)
~3.7 h
Apparent μ
~0.15-0.19 h-1
Test temperature
37°C

Reported conditions

  • 37°C, 11% skim milk, 5 min to 4 h: ~2.1 x 107 to ~3.8 x 107 CFU/mL, apparent td ~4.6 h
  • 37°C, 11% skim milk, 4 h to 8 h: ~3.8 x 107 to ~7.1 x 107 CFU/mL, apparent td ~4.4 h
  • 37°C, 11% skim milk, 8 h to 12 h: ~7.1 x 107 to ~1.5 x 108 CFU/mL, apparent td ~3.7 h

Sources

L. reuteri

Limosilactobacillus reuteri

Probiotic

Useful probiotic adjunct, but slower than starter cultures in conventional dairy unless the substrate is made easier to metabolize.

td (MRS)
~130 min
td (SSF)
~58 min
μmax
0.14-0.31 h-1
Test temp
37°C

Reported conditions

  • 37°C, MRS broth, pH 6.2: GT 2.17 h, μmax 0.14 h-1
  • 37°C, SSF flour blend, pH 6.0: GT 0.96 h, μmax 0.31 h-1
  • Fermentation takeaway: substrate choice cuts doubling time by more than half

Source

L. rhamnosus

Lacticaseibacillus rhamnosus

Probiotic

Widely used probiotic adjunct that grows acceptably at yogurt temperatures but usually trails the starter pair in raw acidification speed.

td (MRS)
~157 min
td (SSF)
~85 min
μmax
0.12-0.21 h-1
Test temp
37°C

Reported conditions

  • 37°C, MRS broth, pH 6.2: GT 2.61 h, μmax 0.12 h-1
  • 37°C, SSF flour blend, pH 6.0: GT 1.41 h, μmax 0.21 h-1
  • SSF lag phase: ~1.98 h before acceleration

Source

L. plantarum

Lactiplantibacillus plantarum

Probiotic

Flexible acid-tolerant adjunct that appears more often in mixed or plant fermentations, but can still be benchmarked against dairy media.

td (MRS)
~124 min
td (SSF)
~82 min
μmax
0.15-0.22 h-1
Test temp
37°C

Reported conditions

  • 37°C, MRS broth, pH 6.2: GT 2.06 h, μmax 0.15 h-1
  • 37°C, SSF flour blend, pH 6.0: GT 1.37 h, μmax 0.22 h-1
  • SSF adaptation: no clear lag phase reported

Source

L. casei / paracasei

Casei group reference

Probiotic

Commercial labels often collapse this group, so the reference combines paracasei kinetics with a whey-based casei benchmark where helpful.

td (MRS)
~99 min
td (SSF)
~66 min
μmax
0.18-0.30 h-1
Test temp
37°C

Reported conditions

  • 37°C, MRS broth, pH 6.2: L. paracasei GT 1.65 h, μmax 0.18 h-1
  • 37°C, SSF flour blend, pH 6.0: L. paracasei GT 1.10 h, μmax 0.27 h-1
  • 37°C, whey + lactose: L. casei μmax 0.299 h-1 in deproteinized cheese whey, derived td ~139 min

Sources

L. gasseri

Lactobacillus gasseri

Probiotic

Human-origin probiotic adjunct studied for gut and urogenital applications rather than fast dairy acidification. It is a comparatively slow grower whose doubling time depends strongly on substrate and pH.

td (fruit juice)
~148 min
td (SVF, pH 4.5)
~4.6-6.3 h
μmax
0.11-0.28 h-1
Test temperature
37-44°C

Reported conditions

  • 44°C, passion fruit juice, pH 7.5: μmax 0.280 h-1, generation time ~2.47 h (~148 min)
  • 44°C, passion fruit + 15% green tea, pH 7.5: μmax 0.187 h-1, generation time ~3.71 h (~223 min)
  • 37°C, simulated vaginal fluid, pH 4.5 (anaerobic): μ 0.11-0.15 h-1 across intestinal and urogenital isolates, derived td ~4.6-6.3 h

Sources

B. coagulans

Bacillus coagulans thermophilic probiotic benchmark

Probiotic

Spore-forming thermophilic adjunct whose apparent growth speed is strongly substrate-dependent: rich MRS can be near starter-adjacent, while low-cost molasses slows sharply.

td (MRS)
60-64 min
td (molasses)
~5.0 h
reported μ
0.14-0.69 h-1
Test temperature
50°C

Reported conditions

  • 50°C, MRS broth: μmax 0.65-0.69 h-1, td ~60-64 min
  • 50°C, glucose/yeast extract/tryptone medium: μ 0.45-0.48 h-1, td ~87-92 min in droplets and flasks
  • 50°C, 1% molasses: μmax 0.14 h-1, td ~5.0 h; 3-5% molasses had no measured 24 h growth in the cited screen

Sources

B. animalis subsp. lactis

BB-12-type bifidobacterial benchmark

Probiotic

Anaerobic bifidobacterial adjunct used for probiotic positioning rather than fast dairy acidification, with growth strongly tied to substrate and oxygen handling.

td
~106 min
μmax
~0.39 h-1
Test temp
37°C
Condition
Anaerobic fortified MRS broth

Reported conditions

  • 37°C, fortified MRS broth with glucose: μmax 0.40 +/- 0.03 h-1, td ~104 min
  • 37°C, fortified MRS broth with lactose: μmax 0.38 +/- 0.03 h-1, td ~109 min
  • Interpretation: practical benchmark is about 100-110 min under anaerobic broth conditions

Source

Kinetic Benchmarks

Reference organisms that help anchor how fast or slow the yogurt-relevant cultures are by comparison.

E. coli K-12

Rich-medium laboratory benchmark

Benchmark

Standard lab comparator for very rapid growth in rich broth; included as a ceiling for what fast bacterial doubling looks like.

td
~20 min
derived μ
~2.08 h-1
Test temp
37°C
Medium
LB broth

Reported conditions

  • 37°C, rich medium: classic textbook-like doubling near 20 min

Source

L. monocytogenes

Listeria monocytogenes

Benchmark

Food-safety benchmark that tolerates cold storage and broad environmental stress, making it a useful contrast to fermentation-focused organisms.

td (37°C)
43.55-48.61 min
Fast test temp
37°C
Cold growth
Possible near 0-4°C
Medium
BHI broth

Reported conditions

  • 37°C, BHI: doubling time 43.55-48.61 min
  • 14°C, diluted BHI: doubling times 12.4-19.9 h reported for food-environment isolates
  • Cold storage risk: growth can still occur during refrigeration rather than fully stopping

Sources