title: Bioenergetics of lactate vs. acetate outside TCA enhanced the hydrogen evolution levels in two newly isolated strains of the photosynthetic bacterium Rhodopseudomonas.
abstract: Two local hydrogen-evolving strains of purple nonsulfur bacteria have been isolated, characterized, and identified as Rhodopseudomonas sp. TUT (strains Rh1 and Rh2). Lactate followed by succinate and malate supported the highest amounts of H2 production, growth (O.D.660nm, proteins and bacteriochlorphyll contents), nitrogenase activity, and uptake hydrogenase; the least of which was acetate. Alginate-immobilized cells evolved higher hydrogen amounts than free cell counterparts. Rh1 was more productive than Rh2 at all circumstances. Lactate-dependent hydrogen evolution was more than twice that of acetate, due to ATP productivity (2/-1, respectively), which is limiting to the nitrogenase activity. The preference of lactate over other acids indicates the feasibility of using these two strains in hydrogen production from dairy wastewater.
authors.affiliation: Botany and Microbiology Department, Faculty of Science, Assiut University, Assiut, Egypt.
authors.forename: Amal W
authors.initials: AW
authors.lastname: Danial
authors.affiliation: Botany and Microbiology Department, Faculty of Science, Assiut University, Assiut, Egypt.
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Abdel Wahab
authors.affiliation: Botany and Microbiology Department, Faculty of Science, Menia University, Menia, Egypt.
authors.forename: Houssam H
authors.initials: HH
authors.lastname: Arafat
authors.affiliation: Botany and Microbiology Department, Faculty of Science, Assiut University, Assiut, Egypt, Phone: 00201010890861, Fax: 0020 88 2342708.
authors.forename: Refat
authors.initials: R
authors.lastname: Abdel-Basset
mesh_terms: D019342:Acetic Acid / Q000378:metabolism / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000464:Alginates / Q000737:chemistry; D001429:Bacteriochlorophylls / Q000096:biosynthesis; D018914:Cells, Immobilized / Q000187:drug effects* / Q000378:metabolism; D004734:Energy Metabolism; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006859:Hydrogen / Q000378:metabolism*; D006864:Hydrogenase / Q000096:biosynthesis; D007700:Kinetics; D019344:Lactic Acid / Q000378:metabolism / Q000494:pharmacology*; D008293:Malates / Q000378:metabolism / Q000494:pharmacology; D009591:Nitrogenase / Q000096:biosynthesis; D010788:Photosynthesis / Q000502:physiology; D012241:Rhodopseudomonas / Q000187:drug effects* / Q000378:metabolism; D019802:Succinic Acid / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000464:Alginates; D001429:Bacteriochlorophylls; D006603:Hexuronic Acids; D008293:Malates; D019344:Lactic Acid; D006859:Hydrogen; C030298:malic acid; D020723:Glucuronic Acid; D000255:Adenosine Triphosphate; D019802:Succinic Acid; D006864:Hydrogenase; D009591:Nitrogenase; D019342:Acetic Acid