Apparent Delay of Product Secretion by Product Adsorption in <i>Aspergillus niger</i>

Emmler, M.; Jungebloud, Anke; Göcke, Yvonne; Cordes, Christiana; Horn, Harald; Hempel, D. C.

doi:10.1002/elsc.200620152

Cited by 3 publications

(2 citation statements)

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“…Their application ranges from new prebiotic products commercially available to the pharmaceutical or the diagnostic sector [ 32 - 34 ]. Glucoamylase (GA, EC 3.2.1.3) is a homologous protein used for hydrolysis of starch in many industrial applications [ 35 ].…”

Section: Introductionmentioning

confidence: 99%

Morphology engineering - Osmolality and its effect on Aspergillus niger morphology and productivity

2011

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BackgroundThe filamentous fungus Aspergillus niger is a widely used strain in a broad range of industrial processes from food to pharmaceutical industry. One of the most intriguing and often uncontrollable characteristics of this filamentous organism is its complex morphology, ranging from dense spherical pellets to viscous mycelia depending on culture conditions. Optimal productivity correlates strongly with a specific morphological form, thus making high demands on process control.ResultsIn about 50 2L stirred tank cultivations the influence of osmolality on A. niger morphology and productivity was investigated. The specific productivity of fructofuranosidase producing strain A. niger SKAn 1015 could be increased notably from 0.5 to 9 U mg-1 h-1 around eighteen fold, by increasing the culture broth osmolality by addition of sodium chloride. The specific productivity of glucoamylase producing strain A. niger AB1.13, could be elevated using the same procedure. An optimal producing osmolality was shown to exist well over the standard osmolality at about 3.2 osmol kg-1 depending on the strain. Fungal morphology of all cultivations was examined by microscope and characterized by digital image analysis. Particle shape parameters were combined to a dimensionless Morphology number, which enabled a comprehensive characterization of fungal morphology correlating closely with productivity. A novel method for determination of germination time in submerged cultivations by laser diffraction, introduced in this study, revealed a decelerated germination process with increasing osmolality.ConclusionsThrough the introduction of the versatile Morphology number, this study provides the means for a desirable characterization of fungal morphology and demonstrates its relation to productivity. Furthermore, osmolality as a fairly new parameter in process engineering is introduced and found to affect fungal morphology and productivity. Osmolality might provide an auspicious and reliable approach to increase the productivity in industrial processes. Because of the predictable behavior fungal morphology showed in dependence of osmolality, a customization of morphology for process needs seems feasible.

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Section: Introductionmentioning

confidence: 99%

Morphology engineering - Osmolality and its effect on Aspergillus niger morphology and productivity

2011

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“…The absence of cell membranes or other barriers allows for fast and convenient manipulation and analysis of the reaction mixtures. In addition, mass transfer and thereby transformation rates can be up to two orders of magnitude higher in cell‐free systems, because cell walls or membranes drop as physical permeability barriers .…”

Section: General Considerations For Cell‐free Biocatalytic Reaction Cmentioning

confidence: 99%

Biosynthesis “debugged”: Novel bioproduction strategies

Guterl

Sieber

2012

Engineering in Life Sciences

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The production of chemicals from biogenic resources is widely performed using microorganisms. These often do not meet the requirements of technical processes due to the narrow limits of microbial physiology. As a consequence, alternatives are sought. Cell‐free enzymatic reaction cascades were recently proposed as next‐generation bioproduction systems. Here, we address problems of microbial systems, show potential advantages of cell‐free concepts and give an overview over the state of the technology. Furthermore, we address current challenges of the cell‐free strategy and give an outlook on future developments.

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