Lactobacillus acidophilus

Lactobacillus acidophilus (Hansen and Mocquot 1970) is one of the comparatively few species that kept the name Lactobacillus after the 2020 taxonomic revision by Zheng and co-workers, which split the old genus into 25 additional genera and united Lactobacillaceae with Leuconostocaceae. Its type strain is ATCC 4356 = DSM 20079 = JCM 1132 = CIP 76.13 = LMG 13550. The cells are Gram-positive, non-sporing rods of roughly 0.6-0.9 x 1.5-6 um occurring singly, in pairs or in short chains. Metabolically it sits in Bergey's obligately homofermentative group: hexoses go through the Embden-Meyerhof pathway to lactic acid with no gas, it grows at 45 C but not at 15 C, and its optimum is 37-42 C. That thermophilic, acid-forming character is why it has been a workhorse dairy culture since long before the probiotic category existed. Thovek supplies the material as a freeze-dried culture concentrate on a maltodextrin carrier, blended to a declared viable count of 100, 150, 200 or 300 billion CFU/g with manufacturing overage so the buyer's label claim holds to the end of shelf life. Viable count is determined by MRS pour plate under anaerobic conditions at 37 C for 72 h; where the sample also contains other lactic acid bacteria or bifidobacteria, the selective MRS-clindamycin method of ISO 20128 | IDF 192 is used, and flow-cytometric active fluorescent unit counts to ISO 19344 | IDF 232 are available on request. Every lot ships with a certificate stating the full strain designation and deposit number, which matters for India-bound and India-origin trade because FSSAI requires probiotic strains to be declared at strain level rather than species level, requires non-GMO strains, and sets a minimum of 10^8 CFU in the recommended daily serving for foods carrying added probiotic ingredients. Growth medium, not the organism, drives the allergen declaration on this species. L. acidophilus has historically been propagated on milk-based media, so a general-purpose lot can carry media-derived milk protein and is neither dairy-free nor vegan. Thovek therefore quotes a dairy-free, soy-free plant-peptone grade separately, declares the media composition and allergen status on every lot certificate, and will not issue a blanket vegan statement against a dairy-media batch. Buyers should also note that the well-known commercial designations NCFM (ATCC 700396), La-14 and DDS-1 are proprietary strains belonging to their respective owners and require a supply licence; Thovek offers documented non-proprietary strains as standard and can arrange licensed material where a brand needs a specific strain dossier.