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Isolation and characterization of proteinase‐ and aminopeptidase‐deficient mutants of Lactobacillus casei subsp. casei IFPL 731
Author(s) -
De Palencia P.Fernández,
MartínHernández M.C.,
Joosten H.M.L.J.,
Peláez C.
Publication year - 1997
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1046/j.1472-765x.1997.00212.x
Subject(s) - lactobacillus casei , aminopeptidase , isolation (microbiology) , microbiology and biotechnology , biology , mutant , lactobacillaceae , streptococcaceae , lactobacillus , biochemistry , fermentation , gene , leucine , amino acid , antibiotics
Proteinase‐deficient (Prt − ) and aminopeptidase‐deficient (Amp − ) variants of Lactobacillus casei subsp. casei IFPL 731 were isolated and characterized. The Prt − mutant was isolated from strains that developed poorly on glucose milk agar. The Amp − mutant was isolated on the basis of its inability to hydrolyse L ‐leucine‐β‐naphtylamide. The Prt − variant developed poorly, while in milk the Amp − variant grew at about the same rate as the parental strain. The characterization of aminopeptidase activity in more detail showed that at least two enzymes are involved The results of the present study suggest that the proteolytic system of Lactobacillus casei is subjected to a regulatory system.