The role of initial spore adhesion in pellet and biofilm formation in Aspergillus niger

Autor: Ulrike Brandt, Arno Kwade, Bert-Ewald Priegnitz, Manfred Rohde, Andreas Wargenau, Andre Fleissner, Sylvia Dietrich, Rainer Krull
Rok vydání: 2012
Předmět:
Zdroj: Fungal Genetics and Biology, 49, 1, pp. 30-8
Fungal Genetics and Biology, 49, 30-8
ISSN: 1087-1845
Popis: Item does not contain fulltext Fungi grow on a great variety of organic and inorganic materials. Colony establishment and growth on solid surfaces require adhesion of spores and hyphae to the substrate, while cell-to-cell interactions among spores and/or hyphae are a prerequisite for the development of three-dimensional mycelial structures such as pellets or biofilms. Surface adherence has been described as a two-step process, comprised of the initial attachment of ungerminated conidia followed by further adhesion of the forming germ tubes and growing hyphae. In the present study, we analyzed the contribution of adhesion of ungerminated spores to pellet and biofilm formation in Aspergillus niger. Mutants deficient in melanin biosynthesis were constructed by the deletion of the alb1 gene, encoding a polyketide synthase essential for pigment biosynthesis. Deltaalb1 conidia have an altered surface structure and changed physicochemical surface properties. Spore aggregation in liquid culture as well as spore surface attachment differ between the wild type and the mutant in a pH-dependent manner. In liquid culture further pellet formation is unaffected by altered spore-spore interactions, indicating that germ tube and hyphal adherence can compensate for deficiencies in the initial step of spore attachment. In contrast, under conditions promoting adhesion of Deltaalb1 conidia to polymer surfaces the mutant forms more stable biofilms than the wild type, suggesting that initial spore adhesion supports sessile growth.
Databáze: OpenAIRE
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