Light–dark duration alternation effects on Rhodobacter sphaeroides growth, membrane properties and bio-hydrogen production in batch culture. (22nd March 2015)

• Record Type: Journal Article
• Authors: Sargsyan, Harutyun; Gabrielyan, Lilit; Hakobyan, Lilit; Trchounian, Armen
• Is Part Of: International journal of hydrogen energy. Volume 40:Number 11(2015)
• Page Start: 4084
• Page End: 4091
• Publication Date: 2015-03-22
• Subjects: Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2015.01.163
• Languages: English
• ISSNs: 0360-3199

Abstract

<abstract xml:lang="en" abstract-type="author" id="abs0010"> <title id="sectitle0010">Abstract</title> <sec> <p id="abspara0010">The effects of light–dark duration alternation on bacterial growth and hydrogen (H<sub>2</sub>) production performance of <italic>Rhodobacter sphaeroides</italic> MDC 6522 from Armenian mineral springs were firstly investigated in batch culture. Five types of light–dark duration were applied: 1st culture was illuminated continuously (control); 2nd and 3rd cultures were illuminated after inoculation during 24–48 h, then dark conditions were applied; 4th and 5th cultures were illuminated after 24–48 h dark period. <italic>R. sphaeroides</italic> did not grow well in the dark conditions, but growth and H<sub>2</sub> production were restored upon illumination. When culture was illuminated after 24 h dark period, H<sub>2</sub> yield was maintained at a constant high level during 96–144 h, and duration of photo-fermentation was delayed up to 144 h, compared to the control. When culture was illuminated till H<sub>2</sub> production started (48 h), and then dark conditions were applied, H<sub>2</sub> production ability of <italic>R. sphaeroides</italic> persisted during the growth up to 120 h, whereas in the control cells H<sub>2</sub> production was not observed. Moreover, the results indicated that light–dark alternation affected the formation of photosynthetic pigments and membrane H<sup>+</sup> conductance. This study is of significant for understanding of bacterial metabolism regulation mechanisms and for application of purple bacteria in H<sub>2</sub> production biotechnology.</p> </sec> </abstract>