ORCID

Abstract

Achromobacter aegrifaciens NCCB 38021 was grown heterotrophically on succinate versus exochemolithoheterotrophically on succinate with thiosulfate as auxiliary electron donor. In batch culture, no significant differences in specific molar growth yield or specific growth rate were found for the two growth conditions, but in continuous culture in the succinate-limited chemostat, the maximum specific growth yield coefficient increased by 23.3% with thiosulfate present, consistent with previous studies of endo- and exochemolithoheterotrophs and thermodynamic predictions. Thiosulfate oxidation was coupled to respiration at cytochrome c551, and thiosulfate-dependent ATP biosynthesis occurred. Specific activities of cytochrome c-linked thiosulfate dehydrogenase (E.C. 1.8.2.2) and two other enzymes of sulfur metabolism were significantly higher in exochemolithoheterotrophically grown cell extracts, while those of succinyl-transferring 2-oxoglutarate dehydrogenase (E.C. 1.2.4.2), fumarate hydratase (E.C. 4.2.1.2) and malate dehydrogenase (NAD+, E.C. 1.1.1.37) were significantly lower—presumably owing to less need to generate reducing equivalents during Krebs’ cycle, since they could be produced from thiosulfate oxidation.

Publication Date

2020-09-28

Publication Title

Archives of Microbiology

ISSN

0302-8933

Acceptance Date

2020-09-02

Deposit Date

2024-06-04

Embargo Period

2021-09-28

First Page

561

Last Page

578

Additional Files
Fig 1.eps (704 kB)
FINAL Fig 2.eps (511 kB)
FINAL Fig 3.eps (4801 kB)
FINAL Fig 5.eps (350 kB)
FINAL Fig 6.eps (1116 kB)
FINAL Fig 4.tif (655 kB)
Download

Additional Files

Fig 1.eps (704 kB)

FINAL Fig 2.eps (511 kB)

FINAL Fig 3.eps (4801 kB)

FINAL Fig 5.eps (350 kB)

FINAL Fig 6.eps (1116 kB)

FINAL Fig 4.tif (655 kB)

Share

COinS