Filaments of green bacterial cells

CSUN microbiologists track the genes that could turn cyanobacteria into biofuel factories

Engineering bacteria to produce complex organic molecules that can be processed into biofuel may be a key to removing fossil fuels from the global energy supply. Tantalizingly, some bacteria produce elevated quantities of potentially useful fatty compounds in “lipid droplets” under the right environmental conditions, and microbiologists at CSUN have identified genes that contribute to this behavior in one species of cyanobacterium, Nostoc punctiforme.

MSci graduate Daisy Arias, BUILD PODER alum Kevin Gomez Pinto, and Professor of Biology Michael Summers worked with collaborator Kerry Cooper at the University of Arizona to examine gene expression in a strain of N. punctiforme that they had engineered to overproduce potentially useful lipids. The DNA sequence of a gene is transcribed to messenger RNA, which can then be translated into proteins — the team measured gene expression by isolating and sequencing the messenger RNA from engineered N. punctiforme and a control strain. They also measured the two strains’ lipid production and growth rates.

This approach identified hundreds of genes that were over- or under- represented in RNA sequences from the engineered strain relative to the control; many of these had functional roles that have not been discovered yet, but many others had known roles in stress response and cellular metabolism. Tracing the roles of these specific genes in other microbes may offer clues to improving output of biofuels or other useful cellular products.

Image: Light-microscope image of Nostoc punctiforme (Eduardo Zuñinga, iNaturalist)