Lactobacillus colini was isolated from an endangered quail species. It was found as part of the intestinal microflora of the bird.

Lactic Acid Bacteria

Lactic Acid Bacteria is a category of bacteria that is composed of several genera and species of bacterial microorganisms. These bacteria are generally known for their ability to produce lactic acid as a product of glucose fermentation. They have specific characteristics which make them distinct from other species of bacteria. 

Morphological and physiological characteristics of LAB:

  • Production of lactic acid as a product of carbohydrate fermentation.
  • Rod or spherical.
  • Present singly or sometimes in pairs.
  • Facultative anaerobes; ability to survive even in the absence of oxygen.
  • Gram-positive in nature; the presence of a peptidoglycan layer and no outer lipid membrane.

Lactic Acid Bacteria

SEM image of a species of LAB

Colony characteristics:

  • Colony size ranges between 2 and 5 micrometers.
  • White or grey colonies are usually observed.
  • Non-motile 
  • Exhibit hemolysis when plated on a blood agar plate. Hemolysis is defined as the destruction of RBCs.

4 colonies of Lactic Acid Bacteria

Isolated species of Lactic Acid Bacteria.

Lactobacillus colini: An introduction

Lactobacillus colini is a species of Lactobacillus bacteria that was isolated from northern bobwhites in the year 2017. In a study that focused on isolating Lactobacillus species from the intestines of quails, this bacterium was isolated and identified. It was grown on Columbia blood agar plates. The main objective of the study was to identify the root cause behind the declination of the local quail population. The bacteria were isolated from non-diseased healthy birds to determine the nature of the relationship between the microorganism and its host. 

Culturing and isolation of L.colini

Lactobacillus colini was isolated from the cultivable bacteria present in the intestinal tracts of northern bobwhites. The bacterial culture conditions were as follows-

  • Bacteria were plated onto a Columbia agar plate with 5% sheep blood.
  • Incubated for 48 hours at room temperature. 
  • Repeated streaking of isolated colonies to obtain a pure culture.
  • The aforementioned step was followed by DNA extraction and isolation.

Colony characteristics:

  • Gram-positive when stained with the gram stain.
  • Cells are present singly or in pairs.
  • Non-spore-forming 
  • Non-motile cells
  • Colony size ranges between 1.5 and 5 mm in diameter.
  • Optimal growth occurs at room temperature and pH 5.5 in the presence of 1% NaCl.
  • Colonies are circular with a flat profile.
  • Colonies are also umbonate with irregular edges. Colonies are opaque in appearance.

Prepared culture media

Growth of Lactobacillus bacteria on a blood agar plate.

It is important to note that the Lactobacillus colini colonies had a distinct clear zone around them due to hemolysis of the blood cells present in the nutrient medium. These bacterial cells were also found to be catalase-negative.

The northern bobwhite and its intestinal microflora

Colinus virginianus, also known as the Virginia quail or the northern bobwhite, is a species of quail that is native to Mexico, Canada, and the USA. These birds are ground-dwelling and can be found throughout the year in grasslands and open fields. They are named so due to their distinct whistle calls. These birds are usually shy and reclusive and rely on their ability to camouflage to hide from predators. They are thought to be monogamous and are often found in pairs. Habitat degradation is the main reason this species is now seeing a decline in its population. 

These birds usually do not survive the nesting period due to active predation and the destruction of their natural habitats. They are omnivores and feed on small invertebrates (ticks, ants, and beetles) apart from shrubs and herbs. The intestinal microflora of these birds is very diverse. The microbiota of these birds is predominantly made up of Lactobacillus species.

Northern bobwhite

A male Virginia quail found in the wild.


Lactobacillus colini is part of the genus Lactobacillus and is found in the intestinal tract of game birds (most commonly the northern bobwhite). These bacteria help in the digestion and maintenance of gut health of their hosts and hence the nature of their relationship with their host organism can be classified as a symbiotic one. The use of this bacterial species in the context of humans is unknown as of now.

Deepika Thilakan


Tags: Lactobacillus colini

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