BioChem - DOS

Effect of light-dark cycles on hydrogen and poly-β-hydroxybutyrate production by a photoheterotrophic culture and Rhodobacter capsulatus using a dark fermentation effluent as substrate

Bioresource technology : biomass, bioenergy, biowastes, conversion technologies, biotransformations, production technologies

Montiel Corona, Virginia; Le Borgne, Sylvie; Revah, Sergio; Morales, Marcia

<P><B>Abstract</B></P> <P>A <I>Rhodobacter capsulatus</I> strain and a photoheterotrophic culture (IZT) were cultivated to produce hydrogen under different light-dark cycles. A dark fermentation effluent (DFE) was used as substrate. It was found that IZT culture had an average cumulative hydrogen production (Paccum H<SUB>2</SUB>) of 1300&plusmn;43mLH<SUB>2</SUB> L<SUP>&minus;1</SUP> under continuous illumination and light-dark cycles of 30 or 60min. In contrast, <I>R. capsulatus</I> reduced its Paccum H<SUB>2</SUB> by 20% under 30:30min light-dark cycles, but tripled its poly-&beta;-hydroxybutyrate (PHB) content (308&plusmn;2mgPHB gdw<SUP>&minus;1</SUP>) compared to continuous illumination. The highest PHB content by IZT culture was 178&plusmn;10mgPHB gdw<SUP>&minus;1</SUP> under 15:15min light-dark cycles. PCR-DGGE analysis revealed that the IZT culture was mainly composed of <I>Rhodopseudomonas palustris</I> identified with high nucleotide similarity (99%). The evaluated cultures might be used for hydrogen and PHB production. They might provide energy savings by using light-dark cycles and DFE valorization.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Photoperiods might offer energy savings in H<SUB>2</SUB> production by photofermentation. </LI> <LI> IZT culture kept H<SUB>2</SUB> production under both continuous lighting and photoperiods. </LI> <LI> H<SUB>2</SUB> production by <I>R. capsulatus</I> declined under photoperiods. </LI> <LI> <I>R. capsulatus</I> tripled and IZT doubled PHB accumulation under photoperiods. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

2017

Elsevier

0960-8524

226

pp.238-246

10.1016/j.biortech.2016.12.021

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART77106209

Light-dark cycles; H2 production; PHB accumulation; IZT culture; DFE treatment