Article Summary 15: Light, Photosynthesis Help Bacteria Invade Fresh Produce

Light, Photosynthesis Help Bacteria Invade Fresh Produce. Science Daily [Internet]. 2009 Sept 29 [cited 2009 Sept 29]. Available from: http://www.sciencedaily.com/releases/2009/09/090928172524.htm

Research shows that a bacteria called Salmonella enterica, a common cause of food poisoning, is showing up more and more on fresh produce like lettuce, tomatoes, and peppers. Studies also show that this bacteria does not just stick to the surface of the produce. Rather, it burrows itself deep into lettuce leaves through plant pores called stomata. By hiding here, the bacteria will not be able to wash away with water.

In a study published this week, researchers in Israel and Tel-Aviv studied the role of light and photosynthesis on the ability of salmonella to infiltrate lettuce leaves through the stomata pores. In order to examine this, they exposed lettuce leaves to bacteria in the dark, in the light, and in the dark after being exposed to light for 30 minutes. Incubation in the light, or in the dark after exposure to the light resulted in masses of bacteria near the stomata and inner leaf tissue. On the contrary, the bacteria was scattered across the surface of the leaf when the lettuce was exposed to bacteria in the dark (where no photosynthesis took place, and the stomata stayed closed).

Now that we know how bacteria enters lettuce, it could have implications on how we need to handle and store fresh produce during harvest, in transit, or while on store shelves. Additionally, we may need to develop new types of sanitizers that will work more effectively.