Relationship Between Energy Substrate Utilization and Specific Growth Rate in Aspergillus nidulans
AUTOR(ES)
Carter, B. L. A.
RESUMO
The maintenance coefficient of glucose-limited Aspergillus nidulans chemostat cultures at 30 C was 0.018 g per g (dry weight) per hr for glucose and 0.55 mmoles per g (dry weight) per hr for oxygen. These values can only be approximate because melanin was produced by the mold at low growth rates and because it is unlikely that this polymer contributed to the maintenance energy requirement although it contributed to the dry weight. Biomass (defined here as dry weight minus melanin) was used to calculate a more meaningful maintenance coefficient for glucose (0.029 g of glucose per g of biomass per hr). At the highest growth rates examined, a nonlinear relationship between growth rate and glucose utilization rate was obtained, suggesting a qualitative change in the metabolic activities of the mold at high growth rates. The oxidative capacity of the mold was highest at the highest growth rates. This observation indicates that the increased substrate utilization rate observed at the higher growth rates is a reflection of enhanced enzyme synthesis. This hypothesis was verified by assaying the specific activities of several enzymes at different growth rates. However, in contrast to all the other enzymes assayed, the activities of reduced nicotinamide adenine dinucleotide phosphate: (acceptor) oxido-reductases were highest at the lowest growth rates.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=247067Documentos Relacionados
- Relationship Between Glucose Utilization and Growth Rate in Bacillus subtilis
- L-histidine utilization in Aspergillus nidulans.
- Attached biomass growth and substrate utilization rate in a moving bed biofilm reactor
- Relationship between temperature and growth rate of bacterial cultures.
- Kinetics of Fungal Growth and Phosphatase Formation in Aspergillus nidulans