title: 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.
abstract: A Rhodobacter capsulatus 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 H2) of 1300±43mLH2L-1under continuous illumination and light-dark cycles of 30 or 60min. In contrast, R. capsulatus reduced its Paccum H2by 20% under 30:30min light-dark cycles, but tripled its poly-β-hydroxybutyrate (PHB) content (308±2mgPHB gdw-1) compared to continuous illumination. The highest PHB content by IZT culture was 178±10mgPHB gdw-1under 15:15min light-dark cycles. PCR-DGGE analysis revealed that the IZT culture was mainly composed of Rhodopseudomonas palustris 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.
authors.affiliation: Doctorado en Biotecnología, División de Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana UAM-Iztapalapa, San Rafael Atlixco 186, C.P. 09340 México, D.F., Mexico.
authors.forename: Virginia
authors.initials: V
authors.lastname: Montiel Corona
authors.affiliation: Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Avenida Vasco de Quiroga 4871, colonia Santa Fe, Delegación Cuajimalpa de Morelos, C.P. 05348 México, D.F., Mexico.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Le Borgne
authors.affiliation: Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Avenida Vasco de Quiroga 4871, colonia Santa Fe, Delegación Cuajimalpa de Morelos, C.P. 05348 México, D.F., Mexico.
authors.forename: Sergio
authors.initials: S
authors.lastname: Revah
authors.affiliation: Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana-Cuajimalpa, Avenida Vasco de Quiroga 4871, colonia Santa Fe, Delegación Cuajimalpa de Morelos, C.P. 05348 México, D.F., Mexico. Electronic address: mmorales@correo.cua.uam.mx.
authors.forename: Marcia
authors.initials: M
authors.lastname: Morales
mesh_terms: D057919:Biological Oxygen Demand Analysis; D004247:DNA / Q000737:chemistry; D058645:Denaturing Gradient Gel Electrophoresis; D005285:Fermentation; D006859:Hydrogen / Q000737:chemistry; D006885:Hydroxybutyrates / Q000737:chemistry*; D007700:Kinetics; D008027:Light; D009711:Nucleotides / Q000737:chemistry; D017440:Photoperiod; D011091:Polyesters / Q000737:chemistry* / Q000378:metabolism; D016354:Rhodobacter capsulatus / Q000378:metabolism*; D012241:Rhodopseudomonas / Q000378:metabolism; D000094122:Polyhydroxybutyrates
chemical_list: D004247:DNA; D006859:Hydrogen; D006885:Hydroxybutyrates; D009711:Nucleotides; D011091:Polyesters; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates
keywords: DFE treatment; H(2) production; IZT culture; Light-dark cycles; PHB accumulation