title: Efficient ethanol production from brown macroalgae sugars by a synthetic yeast platform.
abstract: 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. The genomic integration and overexpression of the gene encoding this transporter, together with the necessary bacterial alginate and deregulated native mannitol catabolism genes, conferred the ability of an S. cerevisiae strain to efficiently metabolize DEHU and mannitol. When this platform was further adapted to grow on mannitol and DEHU under anaerobic conditions, it was capable of ethanol fermentation from mannitol and DEHU, achieving titres of 4.6% (v/v) (36.2 g l(-1)) and yields up to 83% of the maximum theoretical yield from consumed sugars. These results show that all major sugars in brown macroalgae can be used as feedstocks for biofuels and value-added renewable chemicals in a manner that is comparable to traditional arable-land-based feedstocks.
authors.affiliation: 1] Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA [2].
authors.forename: Maria
authors.initials: M
authors.lastname: Enquist-Newman
authors.affiliation: 1] Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA [2].
authors.forename: Ann Marie E
authors.initials: AM
authors.lastname: Faust
authors.affiliation: 1] Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA [2].
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Bravo
authors.affiliation: 1] Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA [2] Manus Biosynthesis Inc., 790 Memorial Drive, Suite 102, Cambridge, Massachusetts 02139 (C.N.S.S.); Calysta Energy, 1140 O'Brien Drive, Menlo Park, California 94025 (D.D.R.); Sutro Biopharma lnc., 310 Utah Avenue, Suite 150, South San Francisco, California 94080, USA (A.G.); Total New Energies USA, 5858 Horton Street, Emeryville, California 94560 (S.A.T.; V.R.).
authors.forename: Christine Nicole S
authors.initials: CN
authors.lastname: Santos
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Raisner
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Arthur
authors.initials: A
authors.lastname: Hanel
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Preethi
authors.initials: P
authors.lastname: Sarvabhowman
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Chi
authors.initials: C
authors.lastname: Le
authors.affiliation: 1] Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA [2] Manus Biosynthesis Inc., 790 Memorial Drive, Suite 102, Cambridge, Massachusetts 02139 (C.N.S.S.); Calysta Energy, 1140 O'Brien Drive, Menlo Park, California 94025 (D.D.R.); Sutro Biopharma lnc., 310 Utah Avenue, Suite 150, South San Francisco, California 94080, USA (A.G.); Total New Energies USA, 5858 Horton Street, Emeryville, California 94560 (S.A.T.; V.R.).
authors.forename: Drew D
authors.initials: DD
authors.lastname: Regitsky
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Susan R
authors.initials: SR
authors.lastname: Cooper
authors.affiliation: Department of Chemical Engineering and Materials Science, Michigan State University, 2527 Engineering Building, East Lansing, Michigan 48824-1226, USA.
authors.forename: Lars
authors.initials: L
authors.lastname: Peereboom
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Alana
authors.initials: A
authors.lastname: Clark
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Yessica
authors.initials: Y
authors.lastname: Martinez
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Joshua
authors.initials: J
authors.lastname: Goldsmith
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Min Y
authors.initials: MY
authors.lastname: Cho
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Donohoue
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Lily
authors.initials: L
authors.lastname: Luo
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Brigit
authors.initials: B
authors.lastname: Lamberson
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Pramila
authors.initials: P
authors.lastname: Tamrakar
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Kim
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Villari
authors.affiliation: 1] Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA [2] Manus Biosynthesis Inc., 790 Memorial Drive, Suite 102, Cambridge, Massachusetts 02139 (C.N.S.S.); Calysta Energy, 1140 O'Brien Drive, Menlo Park, California 94025 (D.D.R.); Sutro Biopharma lnc., 310 Utah Avenue, Suite 150, South San Francisco, California 94080, USA (A.G.); Total New Energies USA, 5858 Horton Street, Emeryville, California 94560 (S.A.T.; V.R.).
authors.forename: Avinash
authors.initials: A
authors.lastname: Gill
authors.affiliation: 1] Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA [2] Manus Biosynthesis Inc., 790 Memorial Drive, Suite 102, Cambridge, Massachusetts 02139 (C.N.S.S.); Calysta Energy, 1140 O'Brien Drive, Menlo Park, California 94025 (D.D.R.); Sutro Biopharma lnc., 310 Utah Avenue, Suite 150, South San Francisco, California 94080, USA (A.G.); Total New Energies USA, 5858 Horton Street, Emeryville, California 94560 (S.A.T.; V.R.).
authors.forename: Shital A
authors.initials: SA
authors.lastname: Tripathi
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Padma
authors.initials: P
authors.lastname: Karamchedu
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Carlos J
authors.initials: CJ
authors.lastname: Paredes
authors.affiliation: 1] Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA [2] Manus Biosynthesis Inc., 790 Memorial Drive, Suite 102, Cambridge, Massachusetts 02139 (C.N.S.S.); Calysta Energy, 1140 O'Brien Drive, Menlo Park, California 94025 (D.D.R.); Sutro Biopharma lnc., 310 Utah Avenue, Suite 150, South San Francisco, California 94080, USA (A.G.); Total New Energies USA, 5858 Horton Street, Emeryville, California 94560 (S.A.T.; V.R.).
authors.forename: Vineet
authors.initials: V
authors.lastname: Rajgarhia
authors.affiliation: Statoil ASA, Statoil Research Centre, Arkitekt Ebbells vei 10, Rotvoll, 7005 Trondheim, Norway.
authors.forename: Hans Kristian
authors.initials: HK
authors.lastname: Kotlar
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Bailey
authors.affiliation: Department of Chemical Engineering and Materials Science, Michigan State University, 2527 Engineering Building, East Lansing, Michigan 48824-1226, USA.
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Miller
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Nicholas L
authors.initials: NL
authors.lastname: Ohler
authors.affiliation: Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA.
authors.forename: Candace
authors.initials: C
authors.lastname: Swimmer
authors.affiliation: 1] Bio Architecture Lab Inc., 604 Bancroft Way, Suite A, Berkeley, California 94710, USA [2] BALChile S.A., Badajoz 100, Oficina 1404, Las Condes, Santiago 7550000, Chile [3] BAL Biofuels S.A., Badajoz 100, Oficina 1404, Las Condes, Santiago 7550000, Chile.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yoshikuni
mesh_terms: D000464:Alginates / Q000378:metabolism; D000693:Anaerobiosis; D001203:Ascomycota / Q000235:genetics / Q000378:metabolism; D056804:Biofuels / Q000600:supply & distribution*; D001709:Biotechnology; D050260:Carbohydrate Metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism*; D019143:Evolution, Molecular; D005285:Fermentation; D005816:Genetic Complementation Test; D005818:Genetic Engineering; D020723:Glucuronic Acid / Q000378:metabolism; D006603:Hexuronic Acids / Q000378:metabolism; D008353:Mannitol / Q000378:metabolism; D000459:Phaeophyceae / Q000235:genetics / Q000378:metabolism*; D011801:Quinic Acid / Q000378:metabolism; D015203:Reproducibility of Results; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D012624:Seaweed / Q000235:genetics / Q000378:metabolism; D014574:Uronic Acids / Q000378:metabolism
chemical_list: D000464:Alginates; D056804:Biofuels; D002352:Carrier Proteins; D006603:Hexuronic Acids; D014574:Uronic Acids; D011801:Quinic Acid; D000431:Ethanol; D008353:Mannitol; D020723:Glucuronic Acid