Gluconic acid production by Aspergillus terreus.
OBJECTIVE
Aspergillus terreus produces itaconic acid at low pH but lovastatin and other secondary metabolites at higher pH in the fermentation. The utilization of glucose as a carbon substrate was investigated for secondary metabolite production by A. terreus.


RESULTS
With a starting pH of 6.5, glucose was rapidly metabolized to gluconic acid by the wild-type strain and by transformants harbouring Aspergillus niger genes encoding 6-phosphofructo-1-kinases with superior kinetic and regulatory properties for bioproduction of metabolites from glucose. On exhaustion of the glucose in batch fermentations, the accumulated gluconic acid was utilized as a carbon source.


CONCLUSIONS
A novel pathway of glucose catabolism was demonstrated in A. terreus, a species whose wild type is, without any strain development, capable of producing gluconic acid at high molar conversion efficiency (up to 0.7 mol mol(-1) glucose consumed).


CONCLUSIONS
Aspergillus terreus is a potential novel producer organism for gluconic acid, a compound with many uses as a bulk chemical. With a new knowledge of glucose catabolism by A. terreus, fermentation strategies for secondary metabolite production can be devised with glucose feeding using feedback regulation by pH.
Dowdells
C
C
beòcarta Ltd., Royal College Building, Glasgow, UK.
Jones
R L
RL
Mattey
M
M
Bencina
M
M
Legisa
M
M
Mousdale
D M
DM
D001230:Aspergillus / Q000378:metabolism*; D001709:Biotechnology / Q000379:methods; D002244:Carbon / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry; D005285:Fermentation; D005942:Gluconates / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology; D010732:Phosphofructokinase-1 / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
D003470:Culture Media; D005942:Gluconates; D011994:Recombinant Proteins; D002244:Carbon; D010732:Phosphofructokinase-1; D005947:Glucose; C030691:gluconic acid