Bioreactor as the root cause of the "manganese effect" during Aspergillus niger citric acid fermentations.

ABSTRACT: High-yield citric acid production by the filamentous Ascomycete fungus Aspergillus niger requires a combination of extreme nutritional conditions, of which maintaining a low manganese (II) ion concentration (<5 μg L^-1) is a key feature. Technical-scale production of citric acid predominantly uses stainless-steel tank fermenters, but glass bioreactors used for strain improvement and manufacturing process development also contain stainless steel components, in which manganese is an essential alloying element. We show here that during citric acid fermentations manganese (II) ions were leaching from the bioreactor into the growth media, resulting in altered fungal physiology and morphology, and significant reduction of citric acid yields. The leaching of manganese (II) ions w

SUBMITTER: Fekete E 

PROVIDER: S-EPMC9386146 | biostudies-literature | 2022

REPOSITORIES: biostudies-literature