ARS | Publication request: IDENTIFICATION OF LACTIC ACID BACTERIA BY RIBOTYPING

Submitted to: Journal of Rapid Methods and Automation in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 25, 1995
Publication Date: N/A

Interpretive Summary: A variety of bacteria are involved in the manufacture of pickles and sauerkraut. It is important for product quality and food safety reasons that only desirable bacteria should be present in these and related vegetable products during manufacture and storage. It has been difficult, however, to tell the different organisms apart. For technical reasons, traditional biochemical tests for identifying bacteria do not work well with these organisms. To get around this problem, we have adapted a DNA "fingerprinting" method, similar to techniques used for criminal forensic studies, to identify specific bacterial organisms. This method will be useful to researchers studying both dairy and vegetable manufacturing processes, allowing a rapid and inexpensive method for identifying isolated bacteria. Use of this method may aid in the development of new bacteria for commercial application and may increase the understanding of how the bacteria participate in the current commercial dairy and vegetable processes. The method may also be used to identify the bacteria in food that cause spoilage and disease in humans. The rapid identification of both the harmful and desirable bacteria may lead to safer and better quality vegetable products.

Technical Abstract: Current methods that can be used for the identification of lactic acid bacteria (LAB) include: biochemical tests, pulsed field gel electrophoresis, and fatty acid analysis. These methods can be costly, time-consuming, and technically difficult. We are investigating the microbial ecology of vegetable fermentations and are interested in the rapid identification of LAB isolates. We have adapted a PCR-based ribotyping method for use with LAB. The PCR product(s) produced contain the sequences from the intergenic spacer regions between the rRNA genes. These products can be resolved by standard agarose or acrylamide gel electrophoresis. Using this method, we have identified PCR product electrophoresis banding patterns for the primary species of LAB found in vegetable fermentations, including those from the genera Lactobacillus, Leuconostoc, Lactococcus, and Pediococcus.