| Lactobacillus | - Gram-positive, non-sporeforming regular rods
- non motile, coccobacilli or long rods
- occur as single cells or in chains
- aerotolerant anaerobes
- mesophilic, some psychrotrophs
- homolactic or heterolactic fermentation
- found in plants, milk, meat, feces |
| Lactobacillus examples | - food bioprocessing: L. delbrueckii subsp. bulgaricus, L. helveticus, L. plantarum - probiotic: Lactobacillus acidophilus, L. casei subsp. casei, L. reuteri - food spoilage: L. sake (hydrogen sulfide in vacuum-packaged beef) - foo biopreservation: some species produce bacteriocins used as food biopreservatives |
| Carnobacterium | - prev. classified as Lactobacillus - similar in most characeristics - gram-positive, non-sporeforming regular rods - differences: unable to grow on acetate medium, synthesize oleic acid, facultative anaerobes, heterofermentative - spoilage organism - can grow in refrigerated meats - some strains produce bacteriocins |
| Brochothrix | - gram-positive, non-sporeforming regular rods
- similar in many characteristics to lactobacilli
- non motile rods
- facultative anaerobes
- meat spoilage organism
- homofermentative
- grow in refrigerated vacuum-packaged meat and meat products |
| Listeria | - gram-positive, non-sporeforming regular rods
- short motile rods
- single or in short chains
- facultative anaerobes
- psychrotrophic
- grow rapidly at 7-10 C
- ubiquitous in the environment and food processing areas |
| Listeria example | Listeria monocytogenes: human pathogen, can grow in monocytes (white blood cells), can cross the placental barrier and infect the human fetus |
