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Development of a Rhodobacter capsulatus self‐reporting model system for optimizing light‐dependent, [FeFe]‐hydrogenase‐driven H 2 production
Author(s) -
Wecker Matt S.A.,
Beaton Stephen E.,
Chado Robert A.,
Ghirardi Maria L.
Publication year - 2017
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.26076
Subject(s) - rhodobacter , hydrogenase , nitrogenase , strain (injury) , chemistry , biochemistry , clostridium acetobutylicum , biology , enzyme , nitrogen fixation , mutant , gene , organic chemistry , nitrogen , ethanol , anatomy , butanol
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 (Ghirardi et al., 2009 Photobiological hydrogen‐producing systems. Chem Soc Rev 38(1):52–61). 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. 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 . Biotechnol. Bioeng. 2017;114: 291–297. © 2016 Wiley Periodicals, Inc.