Previous Article | Next Article ![]()
Appl. Environ. Microbiol., Jul 1997, 2702-2707, Vol 63, No. 7
K Erlandson and CA Batt
A hydrophobic grid membrane filtration (HGMF) colony hybridization assay
was developed that allows strain-specific differentiation of defined
bacterial populations. The randomly amplified polymorphic DNA (RAPD)
fingerprinting technique was used to identify potential signature nucleic
acid sequences unique to each member of a commercial cheese starter culture
blend. The blend consisted of two closely related Lactococcus lactis subsp.
cremoris strains, 160 and 331, and one L. lactis subsp. lactis strain, 210.
Three RAPD primers (OPX 1, OPX 12, and OPX 15) generated a total of 32
products from these isolates, 20 of which were potential strain-specific
markers. Southern hybridization analyses revealed, that the RAPD-generated
signature sequences OPX15-0.95 and a 0.36-kb HaeIII fragment of OPX1-1.0b
were specific for strains 331 and 210, respectively, within the context of
the test starter culture blend. These strain-specific probes were used in a
HGMF colony hybridization assay. Colony lysis, hybridization, and
nonradioactive detection parameters were optimized to allow specific
differentiation and quantitation of the target strains in the mixed starter
culture population. When the 210 and 331 probes were tested at their
optimal hybridization temperatures against single cultures, they detected
100% of the target strain CFUs, without cross-reactivity to the other
strains. The probes for strains 210 and 331 also successfully detected
their targets in blended cultures even with a high background of the other
two strains.
Copyright © 1997, American Society for Microbiology
Strain-specific differentiation of lactococci in mixed starter culture populations using randomly amplified polymorphic DNA-derived probes
Institute of Food Science, Cornell University, Ithaca, New York 14853, USA.
This article has been cited by other articles:
| J. Bacteriol. | Microbiol. Mol. Biol. Rev. | Eukaryot. Cell | All ASM Journals |
|---|