Patrisha Pham-Bugayong, left, and Giovanna Aita are studying methods to make syrup from energycane and sweet sorghum bagasse in Aita’s lab at the LSU AgCenter Audubon Sugar Institute. The syrup can be used as feedstock to generate green biofuels and chemicals. (Photo by A. Denise Attaway)

News Release Distributed 05/06/14

ST. GABRIEL, La. – Researchers at the LSU AgCenter Audubon Sugar Institute are studying ways to make syrup from energycane and sweet sorghum bagasse to be used as feedstock for the generation of green biofuels and chemicals.

Bagasse, a fibrous material left after the juice has been pressed from energycane and sweet sorghum plants, contains cellulose and hemicellulose – two components of plant matter or biomass comprised of sugar polymers. Lignin, a glue-like substance, is a third component of biomass that holds cellulose and hemicellulose together and makes it difficult for enzymes to act on these sugars.

A pretreatment process developed in Giovanna Aita’s research laboratory removes lignin from the biomass material to expose these sugars.

“Our process helps soften the bagasse or biomass material and makes these sugar polymers more reachable by enzymes,” said Aita, an LSU AgCenter associate professor leading this study. “Enzymes break down the sugar polymers found in bagasse into individual sugars to yield liquors from which syrups can be made.”

Simple sugars are building blocks for many chemicals. The challenge, however, is to separate non-sugar components, which are generated during pretreatment and enzyme hydrolysis, from simple sugars to create syrups of specific quality and purity, Aita said.

“Non-sugar components the researchers want to extract include organic acids, furaldehydes and phenolic acids, which have added value elsewhere,” she said. “Non-sugar components such as phenolic acids can be used in textiles and polymer industries, while the organic acids can be used in the food industry and furaldehydes can be used in the fuel industry.”

The researchers have characterized most of the non-sugar components and are evaluating various technologies for removing them from the liquor.

“We are trying to find a balance point,” said Patrisha Pham-Bugayong, a post-doctoral researcher in Aita’s renewable fuels and chemicals laboratory. “We want to determine which method to use so that we minimize the sugars lost in the process and thus have high sugar content in the syrup.”

This study is part of an overall project called the Sustainable Bioproducts Initiative, which involves a team of university and industry partners who are studying the production of biomass for economically viable conversion to biofuels and bioenergy.

The Initiative is made possible by a $17.2 million grant from the United States Department of Agriculture through its Agriculture and Food Research Initiative.

A. Denise Attaway