Premium
Production of growth‐inhibiting factors by Lactobacillus delbrueckii
Author(s) -
Van De Guchte M.,
Ehrlich S.D.,
Maguin E.
Publication year - 2001
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1046/j.1365-2672.2001.01369.x
Subject(s) - lactobacillus , streptococcus thermophilus , bacteria , microbiology and biotechnology , lactobacillus delbrueckii subsp. bulgaricus , lactobacillaceae , bacteriocin , food science , biology , agar , streptococcaceae , lactic acid , ultrafiltration (renal) , chemistry , biochemistry , fermentation , antimicrobial , antibiotics , genetics
Aims: The detection of growth‐inhibiting factors produced by Lactobacillus delbrueckii . Methods and Results: A bioscreen assay was developed to study the effect of Lact. delbrueckii culture supernatant fluids on the growth of phylogenically or functionally related bacteria in broth cultures. Several growth‐inhibiting factors could be distinguished based on differential effects on different test strains, separation by ultrafiltration and sensitivity to heat, proteinase treatment or catalase addition. Conclusions:Lactobacillus delbrueckii strain VI1007 was found to produce at least three growth‐inhibiting factors, other than lactic acid, when grown under microaerobic conditions in MRS broth. These included H 2 O 2 and a bacteriocin‐like, heat‐ and proteinase‐sensitive bactericidal molecule or complex with a molecular weight greater than 50 kDa. A third factor inhibited the growth of Streptococcus thermophilus . Significance and Impact of the Study: The assay system used allows the detection of subtle interactions between strains, that are likely to be of ecological importance in mixed cultures but would go unnoticed in classical agar diffusion tests.