Efficient ethanol production from brown macroalgae sugars by a synthetic yeast platform.

The increasing demands placed on natural resources for fuel and food production require that we explore the use of efficient, sustainable feedstocks such as brown macroalgae. The full potential of brown macroalgae as feedstocks for commercial-scale fuel ethanol production, however, requires extensive re-engineering of the alginate and mannitol catabolic pathways in the standard industrial microbe Saccharomyces cerevisiae. Here we present the discovery of an alginate monomer (4-deoxy-L-erythro-5-hexoseulose uronate, or DEHU) transporter from the alginolytic eukaryote Asteromyces cruciatus.

Implementation of stable and complex biological systems through recombinase-assisted genome engineering.

Evaluating the performance of engineered biological systems with high accuracy and precision is nearly impossible with the use of plasmids due to phenotypic noise generated by genetic instability and natural population dynamics. Minimizing this uncertainty therefore requires a paradigm shift towards engineering at the genomic level. Here, we introduce an advanced design principle for the stable installment and implementation of complex biological systems through recombinase-assisted genome engineering (RAGE).

An engineered microbial platform for direct biofuel production from brown macroalgae.

Prospecting macroalgae (seaweeds) as feedstocks for bioconversion into biofuels and commodity chemical compounds is limited primarily by the availability of tractable microorganisms that can metabolize alginate polysaccharides. Here, we present the discovery of a 36-kilo-base pair DNA fragment from Vibrio splendidus encoding enzymes for alginate transport and metabolism. The genomic integration of this ensemble, together with an engineered system for extracellular alginate depolymerization, generated a microbial platform that can simultaneously degrade, uptake, and metabolize alginate.