Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Search research articles

Related Experiment Videos

Plasmid-mediated reduced phage sensitivity in Streptococcus lactis KR5.

B R Froseth¹, S K Harlander, L L McKay

¹Department of Food Science and Nutrition, University of Minnesota, St. Paul 55108.

Journal of Dairy Science

|February 1, 1988

Summary

Plasmid DNA in Streptococcus lactis KR5 is linked to phage insensitivity. Curing plasmids increased phage sensitivity, indicating their role in defense mechanisms against bacteriophages in dairy streptococci.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Scanning Electron Microscopy of Microbial Attachment to Milk Contact Surfaces <sup>1</sup>.

Journal of food protection·2019

Same author

Characterization of the Highly Autolytic Lactococcus lactis subsp. cremoris Strains CO and 2250.

Applied and environmental microbiology·2006

Same author

Influence of calcium and phosphorus, lactose, and salt-to-moisture ratio on Cheddar cheese quality: changes in residual sugars and water-soluble organic acids during ripening.

Journal of dairy science·2006

Same author

Identification of a gene cluster encoding Krebs cycle oxidative enzymes linked to the pyruvate carboxylase gene in Lactococcus lactis ssp. lactis C2.

Journal of dairy science·2000

Same author

Classification of a bacterial isolate, from pozol, exhibiting antimicrobial activity against several gram-positive and gram-negative bacteria, yeasts, and molds.

Journal of food protection·2000

Same author

Characterization of AbiR, a novel multicomponent abortive infection mechanism encoded by plasmid pKR223 of Lactococcus lactis subsp. lactis KR2.

Applied and environmental microbiology·2000

Area of Science:

Microbiology
Molecular Biology
Bacteriophage Research

Background:

Bacteriophage (phage) resistance is crucial for industrial dairy starter cultures like Streptococcus lactis.
The genetic basis for phage insensitivity in S. lactis KR5 was previously unknown.

Purpose of the Study:

To investigate the role of plasmid DNA in the phage insensitivity of Streptococcus lactis KR5.
To identify specific plasmids conferring resistance or sensitivity to phages.

Main Methods:

Plasmid curing using novobiocin treatment.
Protoplast transformation with pooled plasmid DNA.
Agarose gel electrophoresis and restriction endonuclease digestion.

Main Results:

Related Experiment Videos

Plasmid curing led to increased phage sensitivity.
Transformation yielded lactose-positive, phage-sensitive, or lactose-negative, phage-insensitive transformants.
The 27-Mdal plasmid band comprised two plasmids (26 Mdal, pBF61; 29 Mdal, pBF62) linked to phage insensitivity and lactose metabolism, respectively.
pBF61 encoded a restriction/modification system and a plaque size reduction mechanism.

Conclusions:

Plasmid DNA plays a significant role in the phage insensitivity of Streptococcus lactis.
Specific plasmids, like pBF61, confer reduced phage sensitivity through defined molecular mechanisms.