An Engineered Microbial Platform for Direct Biofuel Production from Brown Macroalgae

Abstract: 

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. When further engineered for ethanol synthesis, this platform enables bioethanol production directly from macroalgae via a consolidated process, achieving a titer of 4.7% volume/volume and a yield of 0.281 weight ethanol/weight dry macroalgae (equivalent to ~80% of the maximum theoretical yield from the sugar composition in macroalgae).

Author(s): 
Adam J. Wargacki
Effendi Leonard
Maung Nyan Win
Drew D. Regitsky
Christine Nicole S. Santos
Peter B. Kim
Susan R. Cooper
Ryan M. Raisner
Asael Herman
Alicia B. Sivitz
Arun Lakshmanaswamy
Yuki Kashiyama
David Baker
Yasuo Yoshikuni
Article Source: 
Science 335(6066):308-13
Category: 
Basic Biology
Uses of Seaweeds: Fuel or Energy
Uses of Seaweeds: Miscellaneous