Growth effects and assimilation of organic acids in Chemostat and Batch Cultures of Acidithiobacillus caldus

Journal Article · Sat Jan 01 04:00:00 EST 2011 · World Journal of Microbiology and Biotechnology

DOI:https://doi.org/10.1007/s11274-010-0441-4· OSTI ID:1011543

Aston, John E; Apel, William A; Lee, Brady D; Peyton, Brent M

The ability of Acidithiobacillus caldus to grow aerobically using pyruvate, acetate, citrate, 2-ketoglutarate, succinate, and malate as either an electron donor and carbon source (heterotrophic growth), or as a carbon source when potassium tetrathionate was added as an electron donor (mixotrophic growth), was tested in chemostat cultures. Under both heterotrophic and mixotrophic conditions, organic acids were added to a sub-lethal concentration (50 M). Under mixotrophic conditions, potassium tetrathionate was added to an excess concentration (10 mM). No cell growth was observed under heterotrophic conditions; however effluent cell concentrations increased over three-fold when pyruvate was coupled with potassium tetrathionate. Under these conditions, the effluent pyruvate concentration was reduced to below the detection limit (2 M), and oxygen consumption increased by approximately 100%. Although pyruvate provided a carbon source in these experiments, ambient carbon dioxide was also available to the cells. To test whether At. caldus could grow mixotrophically using pyruvate as a sole carbon source and potassium tetrathionate as an electron donor, cells were batch cultured in a medium free of dissolved inorganic carbon, and with no carbon dioxide in the headspace. These experiments showed that At. caldus was able to convert pyruvate between 65 ± 8 and 82 ± 15% of the pyruvate carbon to cellular biomass, depending on the initial pyruvate concentrations. This work is the first to identify a defined organic-carbon source, other than glucose, that At. caldus can assimilate. This has important implications, as mixotrophic and heterotrophic activity has been shown to increase mineral leaching in acidic systems.

• Research Organization: Idaho National Laboratory (INL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC07-05ID14517
• OSTI ID: 1011543
• Report Number(s): INL/JOU-09-16877
• Journal Information: World Journal of Microbiology and Biotechnology, Journal Name: World Journal of Microbiology and Biotechnology Journal Issue: 1 Vol. 27; ISSN 0959-3993
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
Acidithiobacillus caldus
BATCH CULTURE
BINDING ENERGY
BIOMASS
CARBON
CARBON DIOXIDE
CARBON SOURCES
ELECTRONS
GLUCOSE
LEACHING
ORGANIC ACIDS
OXYGEN
POTASSIUM
SENSITIVITY
VALENCE
inhibition
organic acids