Morphological regulation of Aspergillus niger to improve citric acid production by chsC gene silencing

2018 ◽  
Vol 41 (7) ◽  
pp. 1029-1038 ◽  
Author(s):  
Xiaowen Sun ◽  
Hefang Wu ◽  
Genhai Zhao ◽  
Zhemin Li ◽  
Xihua Wu ◽  
...  
Keyword(s):  
Citric Acid ◽  
Aspergillus Niger ◽  
Gene Silencing ◽  
Acid Production ◽  
Citric Acid Production

scholarly journals The Effect of Lipids on Citric Acid Production by an Aspergillus niger Mutant

1963 ◽  
Vol 30 (3) ◽  
pp. 365-379 ◽  
Author(s):  
N. F. MILLIS ◽  
B. H. TRUMPY ◽  
B. M. PALMER
Keyword(s):  
Citric Acid ◽  
Aspergillus Niger ◽  
Acid Production ◽  
Citric Acid Production

Optimization of Trace Metals Concentration on Citric Acid Production by Aspergillus niger NRRL 2001

2007 ◽  
Vol 1 (3) ◽  
pp. 246-253 ◽  
Author(s):  
A. A. Guilherme ◽  
G. A. S. Pinto ◽  
S. Rodrigues
Keyword(s):  
Citric Acid ◽  
Trace Metals ◽  
Aspergillus Niger ◽  
Acid Production ◽  
Citric Acid Production

EFFECT OF FERROCYANIDE ON GROWTH AND CITRIC ACID PRODUCTION BY ASPERGILLUS NIGER

1966 ◽  
Vol 12 (5) ◽  
pp. 901-907 ◽  
Author(s):  
H. Horitsu ◽  
D. S. Clark
Keyword(s):  
Citric Acid ◽  
Aspergillus Niger ◽  
Acid Production ◽  
Krebs Cycle ◽  
Acid Formation ◽  
Citric Acid Production ◽  
Resting Cells ◽  
Acid Yield ◽  
Beet Molasses ◽  
Inhibition Of Growth

Ferrocyanide at concentrations of less than 30 p.p.m. (the amount tolerated in citric acid fermentation of beet molasses) had no measurable effect on citric acid production or on the oxidation of glucose or Krebs cycle compounds by resting cells of Aspergillus niger or on the growth rate of this organism during submerged fermentation of beet molasses. Concentrations above 30 p.p.m., however, stimulated citric acid formation in resting cells, but markedly inhibited cell development in growing cells. This inhibition of growth was the main cause of the detrimental effect of high concentrations of ferrocyanide on citric acid formation in molasses; good growth throughout the fermentation was essential to high acid yield, inhibition of growth could be released at any time during the fermentation by addition of sufficient ZnSO4 to reduce the ferrocyanide content to below 30 p.p.m. No evidence that ferrocyanide favors citric acid accumulation by blocking a reaction in the Krebs cycle was found.

scholarly journals The effects of external Mn2+ concentration on hyphal morphology and citric acid production are mediated primarily by the NRAMP-family transporter DmtA in Aspergillus niger

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Balázs Fejes ◽  
Jean-Paul Ouedraogo ◽  
Erzsébet Fekete ◽  
Erzsébet Sándor ◽  
Michel Flipphi ◽  
...  
Keyword(s):  
Citric Acid ◽  
Aspergillus Niger ◽  
Acid Production ◽  
Parent Strain ◽  
Transmembrane Protein ◽  
Citric Acid Production ◽  
High Yield ◽  
Industrial Biotechnology ◽  
High Sequence Identity ◽  
Hyphal Morphology

Abstract Background Citric acid, a commodity product of industrial biotechnology, is produced by fermentation of the filamentous fungus Aspergillus niger. A requirement for high-yield citric acid production is keeping the concentration of Mn2+ ions in the medium at or below 5 µg L−1. Understanding manganese metabolism in A. niger is therefore of critical importance to citric acid production. To this end, we investigated transport of Mn2+ ions in A. niger NRRL2270. Results we identified an A. niger gene (dmtA; NRRL3_07789), predicted to encode a transmembrane protein, with high sequence identity to the yeast manganese transporters Smf1p and Smf2p. Deletion of dmtA in A. niger eliminated the intake of Mn2+ at low (5 µg L−1) external Mn2+ concentration, and reduced the intake of Mn2+ at high (> 100 µg L−1) external Mn2+ concentration. Compared to the parent strain, overexpression of dmtA increased Mn2+ intake at both low and high external Mn2+ concentrations. Cultivation of the parent strain under Mn2+ ions limitation conditions (5 µg L−1) reduced germination and led to the formation of stubby, swollen hyphae that formed compact pellets. Deletion of dmtA caused defects in germination and hyphal morphology even in the presence of 100 µg L−1 Mn2+, while overexpression of dmtA led to enhanced germination and normal hyphal morphology at limiting Mn2+ concentration. Growth of both the parent and the deletion strains under citric acid producing conditions resulted in molar yields (Yp/s) of citric acid of > 0.8, although the deletion strain produced ~ 30% less biomass. This yield was reduced only by 20% in the presence of 100 µg L−1 Mn2+, whereas production by the parent strain was reduced by 60%. The Yp/s of the overexpressing strain was 17% of that of the parent strain, irrespective of the concentrations of external Mn2+. Conclusions Our results demonstrate that dmtA is physiologically important in the transport of Mn2+ ions in A. niger, and manipulation of its expression modulates citric acid overflow.

Sign in / Sign up

Export Citation Format

Share Document