Free Republic (EUA)

Enzyme cocktail developed in Brazil powers production of second-generation ethanol

Publicado em 18 agosto 2020

Researchers at the Brazilian Center for Research in Energy and Materials (CNPEM) have genetically engineered a fungus to produce a cocktail of enzymes that break down the carbohydrates in biomass, such as sugarcane trash (tops and leaves) and bagasse, into fermentable sugar for industrially efficient conversion into biofuel.

The development of low-cost enzyme cocktails is one of the main challenges in producing second-generation ethanol.

Second-generation biofuels are manufactured from various kinds of nonfood biomass, including agricultural residues, wood chips and waste cooking oil. The CNPEM research group's process paves the way for optimized use of sugarcane residues to produce biofuels.

The fungus Trichoderma reesei is one of the most prolific producers of plant cell wall-degrading enzymes and is widely used in the biotechnology industry. To enhance its productivity as a biofactory for the enzyme cocktail in question, the researchers introduced six genetic modifications into RUT-C30, a publicly available strain of the fungus. They patented the process and reported it in an article published in the journal Biotechnology for Biofuels.

The bioprocess developed by the CNPEM researchers produced 80 grams of enzymes per liter, the highest experimentally supported titer so far reported for T. reesei from a low-cost sugar-based feedstock. This is more than double the concentration previously reported in the scientific literature for the fungus (37 grams per liter).

Although the platform was customized for the production of cellulosic ethanol from sugarcane residues, he added, it can break down other kinds of biomass, and advanced sugars can be used to produce other biorenewables such as plastics and intermediate chemicals.

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