Characterization of Hydrogen Metabolism in the Multicellular Green Alga Volvox carteri

• Published in: PloS one Vol. 10; no. 4; p. e0125324
• Main Authors: Cornish, Adam J, Green, Robin, Gärtner, Katrin, Mason, Saundra, Hegg, Eric L
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 30.04.2015; Public Library of Science (PLoS)
• Subjects: 08 HYDROGEN; Algae; Algal Proteins - chemistry; Algal Proteins - genetics; Algal Proteins - metabolism; Amino Acid Sequence; Anaerobic conditions; Aquatic plants; BASIC BIOLOGICAL SCIENCES; Biohydrogen; Biological activity; Biological evolution; Chemical properties; Chlamydomonas reinhardtii; Chlorophyta; Cloning, Molecular; Clostridium; Clusters; Energy sources; Fermentation; Gene Expression Profiling; Gene Order; Genes; Genomes; Genomics; Hydrogen; Hydrogen - metabolism; Hydrogenase; Hydrogenase - chemistry; Hydrogenase - genetics; Hydrogenase - metabolism; Metabolism; Microorganisms; Molecular Sequence Data; Multigene Family; Proteins; Sequence Alignment; Volvox; Volvox - genetics; Volvox - metabolism; Volvox carteri; United States > US; East Lansing Michigan; Michigan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0125324

Hydrogen gas functions as a key component in the metabolism of a wide variety of microorganisms, often acting as either a fermentative end-product or an energy source. The number of organisms reported to utilize hydrogen continues to grow, contributing to and expanding our knowledge of biological hydrogen processes. Here we demonstrate that Volvox carteri f. nagariensis, a multicellular green alga with differentiated cells, evolves H2 both when supplied with an abiotic electron donor and under physiological conditions. The genome of Volvox carteri contains two genes encoding putative [FeFe]-hydrogenases (HYDA1 and HYDA2), and the transcripts for these genes accumulate under anaerobic conditions. The HYDA1 and HYDA2 gene products were cloned, expressed, and purified, and both are functional [FeFe]-hydrogenases. Additionally, within the genome the HYDA1 and HYDA2 genes cluster with two putative genes which encode hydrogenase maturation proteins. This gene cluster resembles operon-like structures found within bacterial genomes and may provide further insight into evolutionary relationships between bacterial and algal [FeFe]-hydrogenase genes.