ISSN:
1573-0972
Keywords:
Aspergillus niger
;
citric acid
;
glycolytic rate
;
oxalic acid
;
solid state fermentation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Abstract A study was performed to understand the physiology and biochemical mechanism of citric acid accumulation during solid state fermentation of sweet potato using Aspergillus niger Yang No.2. A low citrate-producing mutant was isolated followed by a comparative study of the fermentation process and selected physiological and biochemical parameters. In contrast with the parent strain, the mutant strain displayed lower concentrations, yields and production rates of citric acid, accompanied by higher concentrations, yields and production rates of oxalic acid. In addition, the mutant utilized starch at a lower rate although higher concentrations of free glucose accumulated in the cultures. Biochemical analyses revealed lower rates of glucose uptake and hexokinase activity of the mutant strain in comparison with the parent strain. It is proposed that, in common with submerged fermentation, over-production of citric acid in solid state fermentation is related to an increased glucose flux through glycolysis. At low glucose fluxes, oxalic acid is accumulated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008993622446
Permalink
