The metabolome of the model species Chlamydomonas reinhardtii has been analyzed during 120 h of sulfur depletion to induce anaerobic hydrogen (H₂) production, using NMR spectroscopy, gas chromatography coupled to mass spectrometry, and TLC. The results indicate that these unicellular green algae consume freshly supplied acetate in the medium to accumulate energy reserves during the first 24 h of sulfur depletion. In addition to the previously reported accumulation of starch, large amounts of triacylglycerides were deposited in the cells. During the early 24- to 72-h time period fermentative energy metabolism lowered the pH, H₂ was produced, and amino acid levels generally increased. In the final phase from 72 to 120 h, metabolism slowed down leading to a stabilization of pH, even though some starch and most triacylglycerides remained. We conclude that H₂ production does not slow down due to depletion of energy reserves but rather due to loss of essential functions resulting from sulfur depletion or due to a build-up of the toxic fermentative products formate and ethanol.

Item Type:	Refereed Article
Keywords:	metabolome, chlamydomonas reinhardtii, anaerobic hydrogen production, green algae
Research Division:	Biological Sciences
Research Group:	Plant biology
Research Field:	Plant physiology
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the biological sciences
UTAS Author:	Smith, SM (Professor Steven Smith)
ID Code:	101475
Year Published:	2009
Web of Science® Times Cited:	111
Deposited By:	Plant Science
Deposited On:	2015-06-24
Last Modified:	2016-09-30
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