title: 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).
authors.affiliation: Bio Architecture Lab, 604 Bancroft Way, Suite A, Berkeley, CA 94710, USA.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Wargacki
authors.forename: Effendi
authors.initials: E
authors.lastname: Leonard
authors.forename: Maung Nyan
authors.initials: MN
authors.lastname: Win
authors.forename: Drew D
authors.initials: DD
authors.lastname: Regitsky
authors.forename: Christine Nicole S
authors.initials: CN
authors.lastname: Santos
authors.forename: Peter B
authors.initials: PB
authors.lastname: Kim
authors.forename: Susan R
authors.initials: SR
authors.lastname: Cooper
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Raisner
authors.forename: Asael
authors.initials: A
authors.lastname: Herman
authors.forename: Alicia B
authors.initials: AB
authors.lastname: Sivitz
authors.forename: Arun
authors.initials: A
authors.lastname: Lakshmanaswamy
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kashiyama
authors.forename: David
authors.initials: D
authors.lastname: Baker
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yoshikuni
mesh_terms: D000464:Alginates / Q000737:chemistry / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D056804:Biofuels; D001692:Biological Transport; D018533:Biomass; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005798:Genes, Bacterial; D005947:Glucose / Q000378:metabolism; D020723:Glucuronic Acid / Q000737:chemistry / Q000378:metabolism; D006603:Hexuronic Acids / Q000737:chemistry / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism; D008353:Mannitol / Q000378:metabolism; D060847:Metabolic Engineering; D053858:Metabolic Networks and Pathways; D016366:Open Reading Frames; D000459:Phaeophyceae / Q000378:metabolism*; D011133:Polysaccharide-Lyases / Q000235:genetics / Q000378:metabolism; D012624:Seaweed / Q000378:metabolism*; D014733:Vibrio / Q000201:enzymology* / Q000235:genetics
chemical_list: D000464:Alginates; D001426:Bacterial Proteins; D056804:Biofuels; D002352:Carrier Proteins; D006603:Hexuronic Acids; D019344:Lactic Acid; D000431:Ethanol; D008353:Mannitol; D020723:Glucuronic Acid; D011133:Polysaccharide-Lyases; C016158:poly(beta-D-mannuronate) lyase; D005947:Glucose