Toggle Main Menu Toggle Search

Open Access padlockePrints

Investigation of potential reasons for bacterial survival on 'ready-to-eat' leafy produce during exposure to gaseous ozone

Lookup NU author(s): Shreya Wani, Emeritus Professor Jerry Barnes, Dr Ian Singleton


Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


Fresh leafy produce, such as lettuce and coriander, are subject to post-harvest microbial contamination and decay. Because of increasing pesticide resistance and consumer pressures, alternative residue-free treatments, such as ozone, are being actively explored and encouraged to reduce microbial loads and curb spoilage of crops in storage/transit. However, several researchers have reported that a component of the bacterial population on leaf surfaces is resistant to ozone treatment. To investigate the potential reasons for this bacterial survival, confocal microscopy was used to visualise microbes on leaf surfaces before and after ozone treatment. Direct observation (live/dead cell staining) of cells after ozone exposure showed that some cells were still alive; this included cells in small colonies as well as individual cells. We hypothesised that cell (colony) age and prior stress (cold) contributes to, or is responsible for, the ozone resistance observed. Interestingly, cells derived from older agar-grown colonies (7-12-day-old) and cold stressed cells of a Pseudomonas sp. (isolated from coriander) showed higher ozone resistance than that of control cells (4-day-old colonies). These findings suggest that a range of factors are responsible for ozone resistance and further work to improve our understanding of the mechanisms of ozone resistance may lead to improved methods to reduce microbial spoilage of fresh produce. (C) 2015 Published by Elsevier By.

Publication metadata

Author(s): Wani S, Barnes J, Singleton I

Publication type: Article

Publication status: Published

Journal: Postharvest Biology and Technology

Year: 2016

Volume: 111

Pages: 185-190

Print publication date: 01/01/2016

Online publication date: 30/08/2015

Acceptance date: 13/08/2015

ISSN (print): 0925-5214

ISSN (electronic): 1873-2356

Publisher: Elsevier


DOI: 10.1016/j.postharvbio.2015.08.007


Altmetrics provided by Altmetric


Funder referenceFunder name
AHDB/Horticulture Development Company (HDC)
FV 386