Lactobacillus gigeriorum was first isolated from the crop of chickens in the early 1980s by the Institut National de Recherche Agronomique, in Nantes, France.
The genus Lactobacillus: An overview
Bacterial species belonging to this genus are generally known for their probiotic benefits and acidophilic nature. They are industrially significant and are used in the fermentation and culinary industries. These bacteria possess very distinct characteristics that make them easy to identify and isolate. They are ubiquitously present both around us and within us. These bacterial species make up a large part of both human and animal gastrointestinal gut microflora; they improve digestion and maintain the pH of the gut. Bacteria belonging to this genus are rarely parasitic and usually form a symbiotic relationship with the host organism.
- Range from white to brown
- Gram-positive in nature; thick peptidoglycan cell wall and absence of an outer lipid membrane.
SEM of a species of Lactobacillus
Physiological and metabolic characteristics
- Non-spore forming
- Occur singly and never as a cluster.
- Produce lactic acid as a by-product of glucose fermentation.
- Resistant to low pH conditions.
- Some Lactobacillus species can form capsules around themselves and remain dormant under stressful environmental conditions.
- Typically, round in shape.
- Umbonate; the presence of a protrusion along the edge of the colony.
- Rough texture
- Raised profile; convex.
- Irregular edges.
Lactobacillus spp as viewed under a microscope.
Lactobacillus gigeriorum: An introduction
Lactobacillus gigeriorum was first isolated in the 1980s by French scientists. This bacterium was isolated from the crop of a chicken and was grown on a nutrient agar medium. Its characteristics matched that of bacterial species belonging to the genus Lactobacillus, hence, it was classified as such.
Morphological and physiological characteristics
- Facultative anaerobes
- Rod-shaped with a slight curvature
- Occurrence of bacteria singly or in pairs.
- Non-spore forming
- Punctiform; shaped like a small dot.
- White in color
- Shiny and opaque in appearance
- Half-raised profile
- Irregular edges
- Rough texture with an irregular contour.
Optimal growth conditions
Homofermentative analogs of this bacterial species are grown under the following conditions-
- Optimal growth is observed at room temperature.
- pH range of 4-7
- MRS agar medium
- 0.3% (weight/volume) NaCl
Under the aforementioned conditions, optimal growth of L. gigeriorum is observed. This bacterial species mainly produces D-lactic acid as a by-product of metabolism. It does not produce ethanol during glucose fermentation.
Structure of D-lactic acid
Where is Lactobacillus gigeriorum isolated from?
Lactobacillus gigeriorum was first isolated from the crop of chickens. The main purpose of the crop in chickens is to store food for up to 12 hours. As chickens are at the bottom of the food chain, they have developed certain defense mechanisms which allow them to “eat and run” as they are easy prey for most carnivores. The feed stays in the crop and moves into the gizzard slowly throughout the day. It is located at the base of the esophagus and attached to the glandular stomach of the bird. If the food in the crop is stored for too long and not moved into the stomach for digestion, it can get spoiled and lead to infections.
A chicken with a visibly full crop (seen as a bulge)
Lactobacillus gigeriorum is a bacterial species that is still being studied. It has not yet been confirmed whether this species possesses any probiotic abilities. However, studies have shown that these bacteria might aid the digestion of feed in the crop of chickens.