Biocontrol Science and Technology (2015) 25, 1269-1284

I.L. Bisutti, K. Hirt and D. Stephan (2015)
Influence of different growth conditions on the survival and the efficacy of freeze-dried Pseudomonas fluorescens strain Pf153
Biocontrol Science and Technology 25 (11), 1269-1284
Abstract: High viability, storability and tolerance to variable environmental conditions are key factors in the development of microbial biological control agents (BCAs). The efficacy of microbial BCAs is influenced by the culture conditions and formulation process. Therefore, we investigated the influence of diverse growth conditions on the survival during freeze-drying and on the biocontrol efficacy of Pseudomonas fluorescens strain Pf153. Culture time, temperature and media, mild heat shock and pH change influenced the bacterium viability after freeze-drying. The best survival rate was reached by cultivation in King's broth for 16 or 20 h. Growth temperatures of 25 and 30°C and a mild heat shock at 35°C for one hour influenced the survival rate positively. In all bioassays against Botrytis cinerea on Vicia faba leaves, Pf153 showed a significant increased efficacy compared to the untreated control. No differences of the efficacy between fresh and freeze-dried cells were observed. Furthermore, a growth temperature of 20°C increased the efficacy of Pf153 against B. cinerea. These results underline that the quality of the formulated product can be improved by manipulating the fermentation process.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
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	Broad/faba bean (Vicia faba)
Pseudomonas fluorescens (antagonist)	Botrytis cinerea	Broad/faba bean (Vicia faba)