Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Yogurt Bacteria Type

Name: Melly
Status: student
Grade: n/a
Location: Outside U.S.
Country: Malaysia
Date: Winter 2013-14


Question: Why bacteria in yogurt is gram positive?



Replies:
Hello Melly,

The bacteria in yogurt such as Lactobacillus acidophilus La-5 are able to fight against gram negative e coli bacteria (Enterohemorrhagic Escherichia coli). The gram positive yogurt bacteria may simply be strong enough to crowd out other species. I hope this helps.

http://www.ncbi.nlm.nih.gov/pubmed/?term=Yogurt+Containing+Bioactive+Molecules+Produced+by+Lactobacillus+acidophilus+La-5+Exerts+a+Protective+Effect+against+Enterohemorrhagic+Escherichia+coli+in+Mice

Andrea


Gram negative bacteria have an outer lipid membrane that can have toxic properties and is permeable to small molecules. Gram positive bacteria are composed of 90 percent peptidoglycan, which is not as permeable. Teichoic acids are embedded in the cell wall to make it negatively charged. The chemical composition and cell surface properties of the gram positive cell wall help lactobacillus to be resistant to acidic conditions.

Judy L



Click here to return to the Molecular Biology Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 223
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: November 2011
Weclome To Newton

Argonne National Laboratory