Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2005-5-10
pubmed:abstractText
Three differently metabolically engineered strains, 2 single PHA- and Hup- mutants and one double PHA-/Hup- mutant, of the purple nonsulfur photosynthetic bacterium Rhodobacter sphaeroides RV, were constructed to improve a light-driven biohydrogen production process combined with the disposal of solid food wastes. These phenotypes were designed to abolish, singly or in combination, the competition of H2 photoproduction with polyhydroxyalkanoate (PHA) accumulation by inactivating PHA synthase activity, and with H2 recycling by abolishing the uptake hydrogenase enzyme. The performance of these mutants was compared with that of the wild-type strain in laboratory tests carried out in continuously fed photobioreactors using as substrates both synthetic media containing lactic acid and media from the acidogenic fermentation of actual fruit and vegetable wastes, containing mainly lactic acid, smaller amounts of acetic acia, and traces of higher volatile acids. With the lactic acid-based synthetic medium, the single Hup- and the double PHA-/Hup- mutants, but not the single PHA- mutant, exhibited increased rates of H2 photoproduction, about one third higher than that of the wild-type strain. With the food-waste-derived growth medium, only the single Hup- mutant showed higher rates of H2 production, but all 3 mutants sustained a longer-term H2 photoproduction phase than the wild-type strain, with the double mutant exhibiting overall the largest amount of H2 evolved. This work demonstrates the feasibility of single and multiple gene engineering of microorganisms to redirect their metabolism for improving H2 photoproduction using actual waste-derived substrates.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1436-2228
pubmed:author
pubmed:issnType
Print
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
552-65
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:15645340-Acyltransferases, pubmed-meshheading:15645340-Base Sequence, pubmed-meshheading:15645340-Biodegradation, Environmental, pubmed-meshheading:15645340-Bioreactors, pubmed-meshheading:15645340-Blotting, Southern, pubmed-meshheading:15645340-Gene Silencing, pubmed-meshheading:15645340-Genetic Engineering, pubmed-meshheading:15645340-Hydrogen, pubmed-meshheading:15645340-Lactic Acid, pubmed-meshheading:15645340-Light, pubmed-meshheading:15645340-Molecular Sequence Data, pubmed-meshheading:15645340-Mutagenesis, pubmed-meshheading:15645340-Photochemistry, pubmed-meshheading:15645340-Plasmids, pubmed-meshheading:15645340-Refuse Disposal, pubmed-meshheading:15645340-Rhodobacter sphaeroides, pubmed-meshheading:15645340-Sequence Analysis, DNA, pubmed-meshheading:15645340-Species Specificity
pubmed:articleTitle
Metabolically engineered Rhodobacter sphaeroides RV strains for improved biohydrogen photoproduction combined with disposal of food wastes.
pubmed:affiliation
EniTecnologie S.p.A., Environmental Technology Research Center, Via F. Maritano, 26-20097, San Donato Milanese, Milan, Italy.
pubmed:publicationType
Journal Article, Comparative Study