The present invention provides an improved Streptococcus thermophilus. The invention is based on the surprising finding that a putative lantibiotic operon in Streptococcus thermophilus is required for community formation. The operon is a 6.4 kb region that comprises three open reading frames: a lantibiotic biosynthesis protein (dehydratase—SWISSPROT REF: Q5M6E4), a lantiobiotic biosynthesis protein (cyclase—SWISSPROT REF: Q5M6E3) and a lantibiotic efflux protein (permease—SWISSPROT REF: Q70C59). Inhibiting the function of this operon inhibits community formation. Streptococcus thermophilus with a reduced ability to form communities are useful in the processing, producing or manufacturing of dairy products, in particular cheese, where Streptococcus thermophilus are often used as a starter culture.
