E. coli Nissle 1917
A probiotic E. coli used in humans for over a century (Mutaflor). Colonizes the gut safely, making it the chassis of choice for clinical / gut biomarker biosensors.
Identity
- Species
- Escherichia coli
- Strain
- Nissle 1917 (EcN)
- NCBI taxid
- 316435
- Genome
- NZ_CP007799.1
Safety
- Biosafety level
- BSL-1
- Pathogenic
- No
- GRAS
- No
- Probiotic
- Yes — Marketed as the probiotic Mutaflor; used clinically for gastrointestinal indications.
- Biocontainment
- Engineered auxotrophies (e.g. thyA, dapA) demonstrated for gut-restricted containment.
- BSL-1 basis
- ABSA Risk Group 1; established probiotic with extensive human-safety record.
Lacks defined virulence factors of pathogenic E. coli; strong gut colonization.
Traits
- Gram
- negative
- Oxygen
- facultative
- Optimal temp
- 37 °C
- Doubling time
- ~25 min
- Spore-forming
- No
- Transformable
- Yes
Engineering
- CRISPR tooling
- Standard E. coli dCas9/CRISPRi tooling transfers to EcN.
- Common promoters
- pTet, pBAD, tetracycline / arabinose inducible, in-vivo gut-sensing promoters
- Selection markers
- KanR, CmR
- Toolkits
- SEVA, Synlogic / gut-sensor part sets (academic)
Biosensors using this chassis
Choline sensor (BetI + CRISPRi)
Detects choline, a dietary precursor of the cardiovascular-risk metabolite TMA/TMAO in the gut. The Marionette BetI sensor gates a CRISPRi circuit driving a fluorescent reporter, in the probiotic E. coli Nissle 1917.
EHEC sensor (AI-3/QseC + CRISPRi)
Detects enterohemorrhagic E. coli (EHEC) signalling via the AI-3 / host-adrenergic pathway. The QseC/QseB sensor gates a CRISPRi circuit driving a fluorescent reporter, in the probiotic gut chassis E. coli Nissle 1917.
GI bleeding sensor (heme + CRISPRa)
An ingestible sensor for heme, a marker of gastrointestinal bleeding. The validated HrtR heme sensor gates a CRISPRa circuit driving a luminescent reporter, in the probiotic E. coli Nissle 1917.
Glucose sensor (CRP/cAMP + CRISPRi)
Reports glucose via catabolite repression (CRP/cAMP). When glucose is low, cAMP-CRP activates its promoters; when glucose is high, it switches off. CRP gates a CRISPRi circuit driving a fluorescent reporter, in the probiotic E. coli Nissle 1917 — relevant to gut/metabolic monitoring.
Gut inflammation memory recorder (tetrathionate)
Records a transient gut-inflammation episode and remembers it. A recombinase memory switch, triggered by the tetrathionate sensor, flips a DNA state that persists after the signal is gone — so a single exposure is still detectable days later in stool.
Gut inflammation memory sensor (tetrathionate + CRISPRi)
An ingestible sensor for tetrathionate, a biomarker of gut inflammation. The validated TtrSR sensor gates a CRISPRi circuit driving a fluorescent reporter, in the probiotic E. coli Nissle 1917. Complements the thiosulfate sensor as a second inflammation marker.
Gut inflammation sensor (thiosulfate + CRISPRi)
An ingestible sensor for gut inflammation. The validated thiosulfate two-component sensor (ThsSR) gates a CRISPRi amplifier driving a fluorescent reporter, in the human probiotic E. coli Nissle 1917.
Gut nitric-oxide sensor (NsrR + CRISPRi)
An ingestible sensor for nitric oxide, a marker of intestinal inflammation. The native NsrR NO-sensing repressor gates a CRISPRi circuit driving a fluorescent reporter, in the probiotic E. coli Nissle 1917.
Gut sulfide sensor (CstR + CRISPRa)
An ingestible sensor for hydrogen sulfide / persulfide, a gut-microbial metabolite linked to colitis and colorectal risk. The CstR persulfide-sensing repressor gates a CRISPRa circuit driving a fluorescent reporter, in the probiotic E. coli Nissle 1917.
Oxidative-stress sensor (OxyR + CRISPRa)
An ingestible sensor for hydrogen peroxide / oxidative stress, a marker of gut inflammation. The native OxyR peroxide sensor gates a CRISPRa circuit driving a fluorescent reporter, in the probiotic E. coli Nissle 1917.
Zinc-limitation/calprotectin sensor (Zur + CRISPRa)
An ingestible sensor for host nutritional immunity: the host inflammation protein calprotectin sequesters zinc, and the Zur zinc-uptake regulator reports the resulting zinc limitation. Zur gates a CRISPRa circuit driving a fluorescent reporter, in the probiotic E. coli Nissle 1917.