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    Using particle size analysis to determine the hydrophobicity and suspension of fungal conidia with particular relevance to formulation of biopesticide

    Luke, B. and Nicklin, Jane and Bateman, R. (2014) Using particle size analysis to determine the hydrophobicity and suspension of fungal conidia with particular relevance to formulation of biopesticide. Biocontrol Science and Technology 25 (4), pp. 383-398. ISSN 0958-3157.

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    Fungal formulations are vital for effective biopesticide development. Good formulations help to optimise field efficacy while poor formulations result in product failure. This study aimed to produce a hydrophobicity test that would be appropriate for fungal conidia produced to a commercial quality and determine relative hydrophobicity of fungi from four different genera by using laser diffraction. A particle size analyser was used to determine the hydrophobicity of: three Metarhizium acridum samples, M. anisopliae, Beauveria bassiana, Trichoderma stromaticum, T. harzianum, T. viride and Alternaria eichhorniae conidia, by suspending the conidia in three different liquids: Shellsol T (a mineral oil), water and 0.05 % Tween 80. Hydrophobicity was determined by the size of the particles formed in each of the liquids. All the Metarhizium samples were the most hydrophobic followed by B. bassiana and A. eichhorniae. The Trichoderma samples were the least hydrophobic. As a comparison a phase exclusion assay and a salt-mediated aggregation and sedimentation (SAS) test were performed. It was not possible to get a reliable reading for the B. bassiana, A. eichhorniae and T. viride samples using the phase exclusion assay. The addition of salt in the SAS test did not affect the rate of sedimentation. It was hypothesised that conidia size affected the results of the SAS test that made A. eichhorniae the most hydrophobic conidia. Particle size analysis was a more accurate test for comparing fungi from difference genera compared to the SAS test and phase exclusion assay. PSA was also used to test three emulsions and demonstrated that different formulations had an effect on particle size.


    Item Type: Article
    Additional Information: This is an Accepted Manuscript of an article published in Biocontrol Science and Technology on 21.11.14, available online:
    Keyword(s) / Subject(s): formulation, microbial biopesticides, hydrophobicity, particle size analysis, Metarhizium, Beauveria
    School: Birkbeck Faculties and Schools > Faculty of Science > School of Natural Sciences
    Research Centres and Institutes: Structural Molecular Biology, Institute of (ISMB)
    Depositing User: Administrator
    Date Deposited: 03 Dec 2014 09:10
    Last Modified: 02 Aug 2023 17:13


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