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Title: Development of a Rhodobacter capsulatus self-reporting model system for optimizing light-dependent, [FeFe]-hydrogenase-driven H 2 production

The photosynthetic bacterium Rhodobacter capsulatus normally photoproduces H 2 as a by-product of its nitrogenase-catalyzed nitrogen-fixing activity. Such H 2 production, however, is expensive from a metabolic perspective, requiring nearly four times as many photons as the equivalent algal hydrogenase-based system. Here we report the insertion of a Clostridium acetobutylicum [FeFe]-hydrogenase and its three attendant hydrogenase assembly proteins into an R. capsulatus strain lacking its native uptake hydrogenase. Further, this strain is modified to fluoresce upon sensing H 2. The resulting strain photoproduces H 2 and self-reports its own H 2 production through fluorescence. Furthermore, this model system represents a unique method of developing hydrogenase-based H 2 production in R. capsulatus, may serve as a powerful system for in vivo directed evolution of hydrogenases and hydrogenase-associated genes, and provides a means of screening for increased metabolic production of H 2.
 [1] ;  [2] ;  [2] ;  [3]
  1. GeneBiologics, LLC, Boulder, CO (United States)
  2. United States Air Force Academy, Colorado Springs, CO (United States)
  3. National Renewable Energy Lab. (NREL), Golden, CO (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0006-3592
Grant/Contract Number:
AC36-08GO28308; AC36-08GC28308z
Accepted Manuscript
Journal Name:
Biotechnology and Bioengineering
Additional Journal Information:
Journal Volume: 114; Journal Issue: 2; Journal ID: ISSN 0006-3592
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
09 BIOMASS FUELS; R. capsulatus H2 sensor; high-throughput screening; photobiohydrogen; nitrogenase; H2 production
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1400579