ISSN:
1432-072X
Keywords:
Autotroph
;
Archaebacteria
;
Aquifex
;
Hydrogenobacter
;
Thermoproteus
;
CO2 fixation
;
Reductive citric acid cycle
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The autotrophic carbon fixation pathway was studied in the thermophilic hydrogen oxidizing eubacterium Aquifex pyrophilus and in the thermophilic sulfur reducing archaebacterium Thermoproteus neutrophilus. Neither organism contained ribulose-1,5-bisphosphate carboxylase activity suggesting that the Calvin cycle is not operating. Rather, all enzymes of the reductive citric acid cycle were found in A. pyrophilus. In T. neutrophilus ATP citrate lyase activity was detected which has not been achieved so far; this finding corroborates earlier work suggesting the presence of the reductive citric acid cycle in this archaebacterium. The reductive citric acid cycle for autotrophic CO2 fixation now has been documented in the eubacterial branches of the proteobacteria, in green sulfur bacteria, and in the thermophilic Knallgas bacteria as well as in the branch of the sulfur dependent archaebacteria.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00292082
