Lactobacillus helveticus DPC 4571

Lactobacilli are normal inhabitants of the gastrointestinal tract of man and animals where they are widely considered to exert a number of beneficial roles including immunomodulation, interference with enteric pathogens, and maintenance of a healthy intestinal microflora. The genus Lactobacillus presently comprises more than 50 recognized species of non pathogenic bacteria which in addition to their probiotic effects are useful to human as indispensable agents for the fermentation of foods and feed.Lactobacillus helveticus DPC 4571 is a Swiss cheese isolate that has been thoroughly investigated as a starter and adjunct culture in cheese manufacture and demonstrates a number of highly desirable traits including rapid autolysis, reduced bitterness and increased flavor notes. It has two hundred and thirteen insertion sequence (IS) elements, ten times more than other fully sequenced lactobacilli. Genome alignments revealed an unprecedented level of genome stability between the Lactobacillus species considering the number of IS elements in the L. helveticus genome. Comparative analysis also indicated that the IS elements were not the primary agents of niche adaptation for the L. helveticus genome. A clear bias towards the loss of genes reported to be important for gut colonization was observed for the cheese culture but there was no clear evidence of IS associated gene deletion and decay for the majority of genes lost. An extraordinary level of sequence diversity exists between copies of certain IS elements in the DPC 4571 genome indicating they may represent an ancient component of the L. helveticus genome. (HAMAP: LACH4)