Hydrogen production

Abstract

The enzyme, iron hydrogenase (HydA), has industrial applications for the production of hydrogen, specifically, for catalyzing the reversible reduction of protons to molecular hydrogen. The present invention relates to the isolation of a nucleic acid sequence from the algae Scenedesmus obliquus, Chlamydomonas reinhardtii and Chlorella fusca that encodes iron hydrogenase. The invention further discloses the genomic nucleic acid, c-DNA and the protein sequences for HydA. The genes and gene products may be used in a photosynthetic process for hydrogen production which includes growing a microorganism containing the gene coding for HydA in a culture medium under illuminated conditions sufficient to accumulate an endogenous substrate; depleting a nutrient selected from the group consisting of sulfur, iron, and manganese from the medium; then allowing the culture to become anaerobic by consumption of an endogenous or exogenous substrate in the light.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Application Ser. No. 60 / 269,872, which was filed with the U.S. Patent and Trademark Office on Feb. 16, 2001.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to the isolation of a nucleic acid sequences that encode an enzyme that catalyzes the transfer of electrons to protons for the production of molecular hydrogen, and more particularly to iron hydrogenase and genes encoding for the iron hydrogenase in microscopic organisms known as unicellular green algae. [0004] 2. Prior Art [0005] Molecular hydrogen is currently being considered as a candidate for replacing or supplementing fossil fuels and as a source of clean energy. A potential method for producing hydrogen on a commercial scale is the photobiological production of hydrogen by eukaryotic organisms. Green algae respond to anaerobic stress by switching the oxidative pathway to a...

AI Technical Summary

Benefits of technology

[0009] Accordingly, it is an object of the present invention to provide a gene encoding for hydrogenase and a method for using the gene product for the microbial production of molecular hydr

Problems solved by technology

However, the activity of the hydrogenase is rapidly lost when cells are illuminated because of the immediate inactivation of the reversible hydrogenase by photosynthetically generated O2.

Although continuous purging of H2-producing cultures with inert gases has allowed for the sustained production of H2, such purging is expensive and impractical for large-scale mass cultures of algae.

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