title: High temperature and low acid pretreatment and agarase treatment of agarose for the production of sugar and ethanol from red seaweed biomass.
abstract: To obtain fermentable sugar from agarose, pretreatment of agarose by using acetic acid was conducted for short durations (10-30 min) at low acid concentrations (1-5% (w/v)) and high temperatures (110-130 °C). On testing the pretreated agarose by using an endo-β-agarase I (DagA), an exo-β-agarase II (Aga50D), and neoagarobiose hydrolase (NABH), we observed that the addition of the endo-type agarase did not increase the sugar yield. Use of the crude enzyme of Vibrio sp. EJY3 in combination with Aga50D and NABH including acetic acid pretreatment resulted in a 1.3-fold increase in the final reducing sugar yield (62.8% of theoretical maximum based on galactose and 3,6-anhydrogalactose in the initial agarose), compared to those obtained using Aga50D and NABH only after acetic acid pretreatment. The simultaneous saccharification and fermentation of pretreated agarose yielded ethanol of 37.1% theoretical maximum yield from galactose contained in the pretreated agarose.
authors.affiliation: School of Life Sciences and Biotechnology, Korea University, Seoul 136-713, Republic of Korea.
authors.forename: Hee Taek
authors.initials: HT
authors.lastname: Kim
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Yun
authors.forename: Damao
authors.initials: D
authors.lastname: Wang
authors.forename: Jae Hyuk
authors.initials: JH
authors.lastname: Chung
authors.forename: In-Geol
authors.initials: IG
authors.lastname: Choi
authors.forename: Kyoung Heon
authors.initials: KH
authors.lastname: Kim
mesh_terms: D019342:Acetic Acid / Q000494:pharmacology*; D018533:Biomass; D050260:Carbohydrate Metabolism / Q000187:drug effects; D002241:Carbohydrates / Q000096:biosynthesis*; D002855:Chromatography, Thin Layer; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation / Q000187:drug effects; D005662:Furaldehyde / Q000031:analogs & derivatives / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000494:pharmacology*; D006358:Hot Temperature; D006868:Hydrolysis / Q000187:drug effects; D012624:Seaweed / Q000187:drug effects / Q000378:metabolism*; D012685:Sepharose / Q000378:metabolism*; D014733:Vibrio / Q000201:enzymology
chemical_list: D002241:Carbohydrates; D000431:Ethanol; C008046:5-hydroxymethylfurfural; D012685:Sepharose; D005662:Furaldehyde; D006026:Glycoside Hydrolases; C019624:agarase; D019342:Acetic Acid