Integration of the group c phage JCL1032 of Lactobacillus delbrueckii subsp. lactis and complex phage resistance of the host.
OBJECTIVE
Sequences related to Lactobacillus delbrueckii phage JCL1032 genome integration, the maintenance of lysogeny and putative immunity genes were characterized. Phenotypic changes of the JCL1032 lysogens were investigated.


RESULTS
Integration of JCL1032 DNA into the host genome and the location of phage and bacterial attachment sites were studied by standard molecular methods. The frequency of lysogenization was 10(-7), and stable lysogeny was an even rarer phenomenon. JCL1032 integrates its genome into two distinct host genes of unknown functions. According to EOP (efficiency of plating) and adsorption tests JCL1032 lysogens showed resistance against several virulent and temperate Lactobacillus phages at different steps of phage infection.


CONCLUSIONS
Temperate JCL1032 integrates its genome into bacterial DNA with exceptionally low frequency. JCL1032 lysogens express a complex phage resistance against several Lact. delbrueckii phages. An antagonistic arms race between the temperate phage and its host is proposed.


CONCLUSIONS
This is the first time that the genome integration of a group c Lact. delbrueckii phage has been described. The characterized lysogens could facilitate studies on Lact. delbrueckii phage receptors and phage resistance mechanisms. The genetic information gained from this study benefits the development of integration vectors and phage resistant starters.
Department of Biology, University of Oulu, Oulu, Finland. kriipine@paju.oulu.fi
K-A
KA
Riipinen
L
L
Räisänen
T
T
Alatossava
D001483:Base Sequence; D002611:Cheese; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000032:analysis; D004279:DNA, Viral / Q000032:analysis; D005516:Food Microbiology; D007218:Industrial Microbiology; D048668:Lactobacillus delbrueckii / Q000276:immunology* / Q000821:virology; D008242:Lysogeny / Q000235:genetics*; D008969:Molecular Sequence Data; D039002:Prophages / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D017422:Sequence Analysis, DNA
D004269:DNA, Bacterial; D004279:DNA, Viral