One of the main challenges of second-generation biofuel production is identifying enzymes produced by microorganisms for use in a “cocktail” of enzymes to catalyze biomass hydrolysis, in which the enzymes act together to break down the carbohydrates in sugarcane trash and bagasse, for example, and convert them into simple sugars for fermentation.
A group of researchers at the University of Campinas (UNICAMP), working in partnership with colleagues at the Brazilian Biorenewables National Laboratory (LNBR) in Campinas, São Paulo State, Brazil, have discovered that Trichoderma harzianum, a fungus found in the Amazon, produces an enzyme with the potential to play a key role in enzyme cocktails.
The enzyme, which is called β-glucosidase and belongs to glycoside hydrolase family 1 (GH1), acts in the last stage of biomass degradation to produce free glucose for fermentation and conversion into ethanol. In the laboratory, however, the researchers observed that high levels of glucose inhibited the activity of β-glucosidase.
“We also found that the enzyme’s optimal catalytic activity occurred at 40 °C. This represented another obstacle to use of the enzyme because in an industrial setting, the enzymatic hydrolysis of biomass is performed at higher temperatures, typically around 50 °C,” said Clelton Aparecido dos Santos, a postdoctoral researcher at UNICAMP’s Center for Molecular Biology and Genetic Engineering (CBMEG) with a scholarship from FAPESP.
Read more at Fundação de Amparo à Pesquisa do Estado de São Paulo