Engineering [FeFe] Hydrogenase for Photosynthetic Hydrogen Production
Restricted (Penn State Only)
Author:
Mole, Eric
Area of Honors:
Chemistry
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
Alexey Silakov, Thesis Supervisor Stewart Anthony Mallory, Thesis Honors Advisor Michael J Gorka, Faculty Reader
Keywords:
hydrogenase hydrogen production photosynthesis Photosystem I
Abstract:
[FeFe] hydrogenases possess high potential as components in bio-renewable energy systems, but their inherent oxygen intolerance presents a barrier to their real-world application. The work presented here examines a fusion system between proteins in the photosystem I (PSI) complex of the photosynthesis pathway of cyanobacteria and CbHydA1, an oxygen-tolerant hydrogenase from Clostridium beijerinckii. The fusion system may represent a new and environmentally friendly method of dihydrogen (H2) gas production. Fusion constructs utilizing two different PSI proteins - the PsaC and PsaE subunits - were tested. The PsaC-CbHydA1 fusion was successfully expressed and found to oxidize dihydrogen, although at levels much lower than wild type CbHydA1. Two PsaE-CbHydA1 constructs were expressed, albeit at low concentrations. While both fusion proteins demonstrated signatures of the active cofactor (H-cluster) in FTIR spectroscopy, they did not garner any successful results from tests of their enzymatic functionality. Despite some early success, full characterization and further assays of these systems should be completed before they are fully pursued as viable alternatives to traditional industrial H2 production.