On the origin of the electrostatic surface potential of Aspergillus niger spores in acidic environments

Wargenau, Andreas; Fleißner, André; Bolten, Christoph J.; Rohde, Manfred; Kampen, Ingo; Kwade, Arno

doi:10.1016/j.resmic.2011.07.006

Cited by 38 publications

(32 citation statements)

References 33 publications

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“…The same applies to the conidia of A. niger, which even appear to possess negative surface potentials down to a pH of 2 [10,12,20]. In our previous study [19], we traced this particular behavior to the presence of a melanin-containing surface coating on top of the outer spore wall. It was found that the zeta potential of the spores at pH 2 was shifted from a negative to positive values when the amount of melanin pigments was reduced by the preceding pigment extraction at higher pH values.…”

Section: Discussionmentioning

confidence: 83%

“…contribution from the spore wall. However, as discussed in our previous paper [19], the thickness of the surface coating may also change with the solution pH. This assumption is based on the observation that partial ionization of melanin-associated carboxyl groups is accompanied by an irreversible release of melanin pigments.…”

Section: Influence Of the Ph Value On The Potential Distribution At Nmentioning

confidence: 94%

“…An electrostatic model of the spore surface was built in accordance with our previous findings [19]. The model consists of a planar plate covered by an ionpenetrable coating of thickness δ.…”

Section: Electrostatic Surface Modelmentioning

confidence: 99%

“…(note that the two latter quantities were estimated from the results of titration and extraction experiments [19]). b + (z) and b − (z) were chosen to equal unity for all values of z unless stated otherwise.…”

Section: Determination Of Potential Distributionsmentioning

confidence: 99%

“…In a previous study, we investigated the origin of the electric surface charge of A. niger spores under acidic conditions [19]. In these investigations, the typical electrophoretic behavior of the spores, which is characterized by negative mobilities over a wide range of pH values [10,12,20], was traced to the presence of melanin pigments.…”

Section: Introductionmentioning

confidence: 99%

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Linking aggregation of Aspergillus niger spores to surface electrostatics: a theoretical approach

Wargenau¹,

Kampen²,

Kwade³

2013

Biointerphases

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The effect of medium pH on conidial aggregation during submerged cultivation of Aspergillus niger is considered to originate from the electrostatic surface properties of the spores. As previously shown, these properties are greatly influenced by the presence of a melanin-containing surface coating covering the outer spore wall layer. The present study was designed to elucidate the impact of such a coating on the spores' surface potential and their electrostatic repulsion under acidic conditions. A Poisson-Boltzmann model was proposed and potential profiles across the surface coating of noninteracting and interacting spores were calculated. The surface potentials thus obtained were in line with the observed pH dependence of the zeta potential. This dependence was consistent with the outcome of aggregation experiments. Apparently contradictory results regarding the zeta potential and the aggregation behavior of the spores were obtained when the ionic strength was varied. However, both of these observations could be explained by the model.

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Section: Discussionmentioning

confidence: 83%

Section: Influence Of the Ph Value On The Potential Distribution At Nmentioning

confidence: 94%

Section: Electrostatic Surface Modelmentioning

confidence: 99%

Section: Determination Of Potential Distributionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Linking aggregation of Aspergillus niger spores to surface electrostatics: a theoretical approach

Wargenau¹,

Kampen²,

Kwade³

2013

Biointerphases

Self Cite

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Aspergillus niger Pellets Absorbed Bacillus sp. Isolated from Soybean Wastewater Sludge

Ningning

Wu²,

Zhang

2015

Lecture Notes in Electrical Engineering

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The filamentous fungal pellet—relationship between morphology and productivity

Veiter¹,

Rajamanickam²,

Herwig³

2018

Appl Microbiol Biotechnol

180

133

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Filamentous fungi are used for the production of a multitude of highly relevant biotechnological products like citric acid and penicillin. In submerged culture, fungi can either grow in dispersed form or as spherical pellets consisting of aggregated hyphal structures. Pellet morphology, process control and productivity are highly interlinked. On the one hand, process control in a bioreactor usually demands for compact and small pellets due to rheological issues. On the other hand, optimal productivity might be associated with less dense and larger morphology. Over the years, several publications have dealt with aforementioned relations within the confines of specific organisms and products. However, contributions which evaluate such interlinkages across several fungal species are scarce. For this purpose, we are looking into methods to manipulate fungal pellet morphology in relation to individual species and products. This review attempts to address (i) how variability of pellet morphology can be assessed and (ii) how morphology is linked to productivity. Firstly, the mechanism of pellet formation is outlined. Subsequently, the description and analysis of morphological variations are discussed to finally establish interlinkages between productivity, performance and morphology across different fungal species.

show abstract

On the origin of the electrostatic surface potential of Aspergillus niger spores in acidic environments

Cited by 38 publications

References 33 publications

Linking aggregation of Aspergillus niger spores to surface electrostatics: a theoretical approach

Linking aggregation of Aspergillus niger spores to surface electrostatics: a theoretical approach

Aspergillus niger Pellets Absorbed Bacillus sp. Isolated from Soybean Wastewater Sludge

The filamentous fungal pellet—relationship between morphology and productivity

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