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Cambridge Global Food Security

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Lactic acid-producing bacterium could reduce harmful food contamination

last modified Aug 13, 2015 11:54 AM
A new paper has potential to reduce contamination of food by harmful bacteria - using harmless bacteria biofilms.

by Joanna Wolstenholme, Communications intern

The colonisation of food by bacteria is a major issue for food security, as these bacteria often lead either to food spoiling, or are pathogenic and cause sickness in those consuming the produce. In a recent paper in Microbial Cell Factories, Jalilsood et al discuss the potential of a lactic acid producing, and biofilm forming bacterium isolate, Lactobacillus plantarum PA21, in preventing ‘negative’ (pathogenic or spoiling) bacteria from colanising food, or food processing areas.

L. plantarum forms biofilms (collections of bacteria in a secreted matrix) as well as secreting lactic acid, and the combined effect was found to prevent the growth of other, pathogenic, bacteria where L. plantarum was found. Generally, when bacteria land on a surface to colonise, it is equally as likely that they will land on an area already colanised by a biofilm as the surface itself, and so are able to integrate with the existing population of bacteria. However, with L. plantarum, this is not the case, as it was shown to severely reduce, or in some cases prevent entirely, the growth of ‘negative’ pathogenic organisms.

The authors suggest that there is the potential for cultures of L. plantarum PA21 to be sprayed on industrial food processing surfaces as a ‘house microflora’ to supress the establishment of harmful bacteria. This would lead increase the shelf life and safety of processed foods, as the risk of harmful bacterial contamination would be lowered.


For more detail, see the paper, at