Marine microorganisms reveal new gene clusters for hydrogen production

Genomic studies of hydrogen-producing bacteria reveal completely new gene clusters that can produce large quantities of hydrogen.

The Vibrionidae are a family of marine bacteria known for their bioluminescence, but are also famous for including cholera pathogens in their numbers.

The Bibrionidae were not attractive subjects in biofuel production, but rather emerged as a potential solution of green energy by fermenting the ability to produce such large quantities of hydrogen gas, a family that is another unique feature, and by breaking down a substance called formation into carbon dioxide and hydrogen.

The team currently includes Professor Tomo Sawabe from the Faculty of Fisheries Science at Hokkaido University. Ramesh Kumar Natarajan from the National Institute of Interdisciplinary Science and Technology in India. Fabiano Thompson of the Federal University of Rio de Janeiro, Brazil, used genomic sequencing to investigate the mechanisms behind this biochemical feat.

Their findings can be found in the Journal Current Microbiology.

Researchers examined 16 known vibrionidae species that are often found in symbiotic relationships with deep-sea animals. They focused on the sequence and structure of the HYF-type-forming hydrogen lyloise (FHL) gene cluster.

The hydrogenase enzymes in this gene cluster catalyze hydrogen and carbon dioxide disruption of formation. This complex is in much smaller amounts than the Bibrionaceae family, but is also found in E. coli, another bacteria that can produce hydrogen through fermentation.

“These analyses reveal the relationship between the unexpected diversity of FHL gene clusters and the functioning of gene clusters and hydrogen production capacity,” explains Sawabe.

The team discovered two new types of FHL gene clusters in the family Vibrionidae, bringing the total number of FHL gene clusters in these bacteria to six. They suggest that this diversity in cluster structure has been adapted and evolved to occupy the scope of the ecological niche, and is a consequence of species differentiation of the Bibrionidae family.

This study also found differences in hydrogen fermentation and production associated with various FHL gene clusters. Biblioporteria, found in wild rice living in the marine species Vibriotritonius and mangroves, showed the highest levels of hydrogen production, while Biblioaerogen and Bibliomangrovies were the lowest.

The level of hydrogen production and how well the bacteria formed correlated with how well they worked with the cells.

“These genotypes enhance formation metabolism as an important factor in maintaining fermentable hydrogen production in certain groups of vibrio,” concludes Sawabe.

The findings support the researchers’ suggestion that several species have been driven to evolve higher hydrogen production due to the need to detoxify formation from the environment.

The findings also highlight the evolution of hydrogen fermentation in other bacterial species such as E. coli.