Teri Beattie 09005100

Lactobacilluis casei.external image Lactobacillus%20casei.jpg

Kingdom: Bacteria

Phylum: Firmicutes

Class: Bacilli

Order: Lactobacillales

Family: Lactobacillaceae

Genus: Lactobacillus

Species: Lactobacillus casei.

Lactibacillus casei is a Gram positive, rod shaped bacteria which is also anaerobic, non-sporing and non-motile. Lactobacillus casei is an acid tolerant bacteria, this means that it can survive in harsh environments. It can survive these harsh conditions as it is resistant to both gastric acid and bile. It is a faculative anaerobe which means that is can grow in both aerobic and anaerobic conditions although it develops much faster in the presence of oxygen, it is also a organotroph and its metabolism is homofermentive. It is found naturally in the intestinal tracts of animals and in fermented dairy products, although it is naturally found in the mouth and intestines of humans. Lactobacillus casei has both a wide temperature and pH range. In addition Lactobacillus casei is a mesophile which means its optimum pH is around 5.5 while its optimum temperature is around 30 to 40 degrees celsius. A Lactobacillus casei cell size is around 0.7- 1.1 x 2.0- 4.0 micrometers. Lactobacillus casei obtains most of its energy through converting glucose to lactic acid.

Lactobacillus casei helps to stabilize the distibution of microflora in the gut, this is done through antimicrobial activity, this involves creating an acidic environmeexternal image yakult_468x410.jpgnt that restrics and can stop the growth of bacteria that could cause infections in the gastrointestinal tract. Lactobacillus casei is useful in this way as it is not pathogenic, this means that it does not cause any detrimental effects and can be classed as harmless, it is also recognised as a beneficial microorganism.


Lactobacillus casei is used in yoghurts such as Yakult and Actimel, it is also found in fermented milk, fermented drinks and fermented cheese's. It is also found naturally in green olives and cucumber pickles that have been naturally fermented. Lactobacillus casei is of interest to scientists as it has been known to help diarrhoea, also other strains of this bacteria have been known to have an anti-inflammatory effect on the gut which can help IBS and IBD. It can also reduce lactose intolerance and modulate the immune system and has also been known to alleviate constipation.

Currently research on Lactobacillus casei for applications to biotechnology is being carried out, various studies such as it use in inhibiting E. coli's ability to invade intestinal epithelial cells in Crohn's disease patients. Another recent study looks at the decolourization of azo dyes by lactic acid bacteria.