Genus/species: Lactobacillus jensenii
Gram Stain: Positive
Morphology:
- Cell: rod-shaped, 0.6-0.8 m x 2.0-4.0, Single or short chains, non-spore forming
- Colony: small, smooth, circular, translucent, non-pigmented
- Liquid Growth:
Physiological Traits:
Grows on Blood agar, facultatively heterofermentative; prefers no O2 but can tolerate small amounts of oxygen; grows in presence of 1.5% NaCl but not 3% NaCl. Lactic acid produced from glucose without gas. Catalase- and Oxidase- negative, Produces H2O2
Ecological Traits:
Found mainly in lower female genital tract. Composes 23% of natural vaginal microflora. Found on grapes at time of harvest.
Distinguishing Features:
- Hydrolysis of arginine
- Production of D-lactate (only)
- Readily ferments amygdalin, cellobiose, galactose, D-mannose, salicin, sucrose, and trehalose. (11-90% of strains can ferment arabinose, esculin, gluconate, maltose, mannitol, melibiose, ribose, and sorbitol)
- Cannot ferment lactose, melexitose, mannitol, sorbitol, arabinose, or xylose
- Presence of meso-DAP in peptidoglycan.
Role in wine:
Lactobacillus jensenii can metabolize sorbate in wine and produce off-odors that contribute a “geranium odor.”
Sensitivities:
- SO2:Yes. pH dependent
- Sorbate: Can metabolize
- DMDC: Yes; >50 ppm
- pH: Present in greater concentrations above pH 3.5
- Acids: No data
- Ethanol: In one study different species within Lactobacillus show widely varying tolerances to EtOH
- Anaerobiosis: Sensitive to O2; in presence of O2 acetate is formed rather than lactate
- Heat: Can tolerate temperatures up 45º C
References:
- Edinger, W.D. and D.F. Splittstoesser. Sorbate tolerance by lactic acid bacteria associated with grapes and wine. J. Food Sci. 51:1077-1078. (1986)
- Gold, R.S., M.M. Meagher, R. Hutkins, and T. Conway. Ethanol tolerance and carbohydrate metabolism in lactobacilli. J. Ind. Microbiol. 10:45-54. (1992)