Where’s the lignin in sugarcane bagasse?

Sugarcane: more precise measurements to locate lignin

Léo RamosSugarcane: more precise measurements to locate ligninLéo Ramos

With the aid of confocal optical microscopy, a group of researchers with the São Carlos Institute of Physics (IFSC), at the University of São Paulo (USP), has successfully identified minimum concentrations of lignin in sugarcane bagasse, which is valuable information when it comes to converting biomass into cellulosic ethanol. One of the steps in the chemical pretreatment of bagasse used to produce second-generation ethanol is the removal of lignin, which increases the rigidity of the plant cell wall and interferes with access to the cellulose, thereby hampering the breakdown of sugars. “We applied fluorescent confocal microscopy to map the exact place where the lignin is located in the wall of the sugarcane fiber,” explains Francisco Eduardo Gontijo Guimarães, a researcher involved in the project led by Igor Polikarpov, of IFSC-USP. They believe this will make it possible to assess whether the chemical pretreatments used in the conversion process are effective. “Most of the methods now in use can measure lignin concentrations no lower than 9%, while we’ve already reached 1%,” Guimarães underscores. Using confocal microscopy, Polikarpov’s team has also measured single cell fibers; this represents an advance over current methods, which measure the group of fibers.