Charting the Microbiome of Oilcane: A Study by Researchers

In a new collaboration, scientists at the Center for Advanced Bioenergy and Bioproduct Innovation (CABBI) have identified the types of microbes that associate with engineered oil mold. Further exploration of the microbiome of the oil container may reveal opportunities to benefit from plant-microbe interactions in these feedstocks, which may increase oil yield for sustainable bioenergy production.

In terms of biomass, sugarcane is the most produced crop in the world, and it’s not hard to see why; It provides the feedstock for 26% of the world’s bioethanol and 80% of global sugar production.

A particular type of engineered sugarcane, called oil cane, accumulates 30 to 400 times more energy-dense triglycerides (TAG) than wild-type sugarcane, making it an ideal crop for biofuel production. By studying this feedstock that converts natural sugars to produce oil, researchers can provide sustainable alternatives to plant fossil fuels.

One way researchers are looking to improve crops is to manage the microbiome. Understanding the interactions between plants and the microorganisms that live on and within them may help us develop agricultural management practices that can increase crop yield and resilience. While the sugarcane microbiome has been studied, the oilcane microbiome has historically been uncharted territory.

In a collaboration of CABBI’s Sustainability and Feedstock Production subjects, researchers explored differences in microbiome structure between several wild-type oil and sugarcane accessions. Iowa State researcher Jihoon Yang and assistant professor Adina Howe led the project from the sustainability side, while University of Florida biologist Baskaran Kannan and Professor Freddy Alpeter were lead materials.

The study published in Biotechnology for biofuels and bioproductsexamined the microbes of four different oil-cane accessions (developed by Altpeter’s team at the University of Florida) in comparison to unmodified sugarcane.

The team planted both these reeds and the engineered oil in the same soil. Once grown, they took samples of microbes from leaves, stems, roots, root soil, and loose soil. Using sophisticated sequencing and bioinformatics tools, the team found that each strain of oil cane had different microbiomes than unmodified sugar cane.

Interestingly, the largest differences in microbiome composition were observed in oil intakes that significantly expressed the transgene WRI1. WRI1 is known as the ‘master regulator’ of lipid biosynthesis and contributes to important changes in the gene expression profile, affecting the plant’s ability to synthesize energy-dense TAG.

This study showed that metabolically engineered oilseed accessions that differ in their gene expression will correlate with distinct microbiomes, suggesting that metabolic differences in oil cane (compared to sugarcane) play a role in determining the composition of the plant microbiome.

The researchers hypothesize that the oil field’s association with specific soil microbes may benefit the plant in some way, as it often does in other plants. The team hopes to direct more research toward understanding how the unique microbiomes of certain oilfield species interact with their host plants.

“Insights in this area could lead to breakthroughs in managing the oil industry, where farmers can tailor plant-microbe interactions to improve their crop and oil production,” Howe said.

Alpeter added, “Further research may also lead to a customized microbiome that could enhance agricultural performance and yield from a metabolically modified oil industry.”