Journal of Applied Microbiology (2020) 128, 232-241

I.L. Bisutti and D. Stephan (2020)
Influence of fermentation temperature and duration on survival and biocontrol efficacy of Pseudomonas fluorescens Pf153 freeze-dried cells
Journal of Applied Microbiology 128 (1), 232-241
Abstract:
Aim
The aim of this paper was to determine whether the quality of formulated Pseudomonas fluorescens Pf153 can be influenced by changes in fermentation conditions. In this study, the influence of the fermentation temperature on the growth and its consequence on shelf life, viability and biocontrol efficacy of freeze-dried cells of P. fluorescens Pf153 was investigated.
Methods and Results
Cells of P. fluorescens Pf153 were grown at 20 and 28°C in flasks and fermenter and harvested in the mid-log and the beginning of the stationary phase. The survival during storage of freeze-dried cells was tested at 25°C. Cells fermented at 20°C survived in storage better than those grown at 28°C, irrespective of the harvesting time. Compared to the untreated control, in in vitro tests Pf153 was in all production temperature/duration combinations significantly effective against all tested Botrytis cinerea strains. But no differences between temperature/duration combinations were found. In bioassay on detached Vicia faba leaves, it was found that young cells, when fermented at 28°C had a significant positive influence on the biocontrol efficacy.
Conclusions
These results demonstrate that fermentation parameters have an influence on the performance and quality of a formulated product.
Significance and Impact of the Study
Only limited numbers of biocontrol products based on antagonistic pseudomonads are on the market. This can be attributed to the lack of suitable formulated products with high numbers of viable cells and a good shelf life. Currently, only limited information on the influence of the fermentation on subsequent downstreaming process is available. Within this study, we focused on the influence of the two important parameters fermentation temperature and harvest time on survival, shelf life and biocontrol efficacy of P. fluorescens Pf153.
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Full text of article
Database assignments for author(s): Dietrich Stephan

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
formulation/storage of bioagents

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Botrytis cinerea
Pseudomonas fluorescens (antagonist)	Botrytis cinerea