Pseudomonas reptilivora

Pseudomonas reptilivora is a fluorescent, yellow-green, Gram-negative, rod-shaped, non-spore-forming, multiple polar flagellated, motile bacterium that is pathogenic to reptiles. It was originally isolated in Gila monsters (Heloderma suspectum), horned lizards (Phrynosoma solare), and chuckawallas (Sauromalus ater).^[1] The type strain is ATCC 14836.

Pseudomonas reptilivora
Scientific classification
Domain:	Bacteria
Kingdom:	Pseudomonadati
Phylum:	Pseudomonadota
Class:	Gammaproteobacteria
Order:	Pseudomonadales
Family:	Pseudomonadaceae
Genus:	Pseudomonas
Species:	P. reptilivora
Binomial name
Pseudomonas reptilivora Caldwell and Ryerson 1940

Gluconic Acid Production by Pseudomonas reptilivora

P. reptilivora has demonstrated a remarkable ability to convert glucose into gluconic acid, a valuable organic acid widely used in the food, pharmaceutical, and eco-friendly cleaning industries. This bioconversion occurs through an oxidative process catalyzed by membrane-bound dehydrogenases, particularly pyrroloquinoline quinone (PQQ)-dependent glucose dehydrogenase.^[2]

Metabolic Pathway

Gluconic acid is synthesized via direct oxidation of glucose in the periplasmic space, bypassing central metabolic pathways which is further oxidized to 2-ketogluconic acid by gluconic acid dehydrogenase, however, another enzyme (2-ketogluconate dehydrogenase) transforms 2-ketogluconic acid into 5-ketogluconic acid at an optimal pH 5.5 and 6.0.^[3]

The enzymatic reaction follows:

Glucose + O₂ → Gluconic acid + H₂O₂ ^[2]

Gluconic acid → 2-ketogluconic acid → 5-ketogluconic acid ^[2][3]

Biotechnological Relevance

Gluconic acid produced by P. reptilivora offers several advantages:

• High specificity: The conversion produces minimal byproducts, simplifying downstream purification.
• Mild process conditions: No extreme temperatures or harsh chemicals are needed.
• Low-cost substrates: It can be produced from glucose, glycerol, or agro-industrial carbohydrate-rich wastes.
• Experimental Evidence: In controlled fermentations with glucose concentrations of 1–5% (w/v).

P. reptilivora B-6bs has shown: High conversion yields of glucose to gluconic acid within 48 hours. Co-production of 5-keto-D-gluconate, a secondary product formed by further oxidation. Sensitivity to oxygen transfer rates, with higher productivity observed at 3.3 vvm compared to 2.5 vvm. Production has been confirmed through UV-Vis spectrophotometry and thin-layer chromatography (TLC) techniques.^[2]

Known strains of Pseudomonas reptilivora

• P. reptilivora ^[1]
• P. reptilivora M8 produces antibiotics.^[4]
• P. reptilivora B-6 produces 2-ketogluconic acid.^[5]
• P. reptilivora B-6bs produces 5-ketogluconic acid, proline, glutamic acid and gluconic acid ^[2]