title: Efficacy of acidic pretreatment for the saccharification and fermentation of alginate from brown macroalgae.
abstract: This study was performed to evaluate the effectiveness of acidic pretreatment in increasing the enzymatic digestibility of alginate from brown macroalgae. Pretreatment with 1 % (w/v) sulfuric acid at 120 °C for 30 min produced oligosaccharides, mannuronic acid, and guluronic acid. Enzymatic saccharification of pretreated alginate by alginate lyases produced 52.2 % of the theoretical maximal sugar yield, which was only 7.5 % higher than the sugar yield obtained with unpretreated alginate. Mass spectrometric analyses of products of the two reactions revealed that acidic pretreatment and enzymatic saccharification produced saturated monomers (i.e., mannuronic and guluronic acid) with saturated oligosaccharides and unsaturated monomers (i.e., 4-deoxy-L-erythro-5-hexoseulose uronic acid; DEH), respectively. While DEH is further metabolized by microorganisms, mannuronic acid and guluronic acid are not metabolizable. Because of the poor efficacy in increasing enzymatic digestibility and owing to the formation of non-fermentable saturated monomers, acidic pretreatment cannot be recommended for enzymatic saccharification and fermentation of alginate.
authors.affiliation: Department of Biotechnology, Graduate School, Korea University, Seoul, 02841, Republic of Korea.
authors.forename: Damao
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Biotechnology, Graduate School, Korea University, Seoul, 02841, Republic of Korea.
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Yun
authors.affiliation: Department of Biotechnology, Graduate School, Korea University, Seoul, 02841, Republic of Korea.
authors.forename: Sooah
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Biotechnology, Graduate School, Korea University, Seoul, 02841, Republic of Korea.
authors.forename: Do Hyoung
authors.initials: do H
authors.lastname: Kim
authors.affiliation: Graduate School of Analytical Science and Technology, Asia-Pacific Glycomics Reference Site, Chungnam National University, Daejeon, 34134, Republic of Korea.
authors.forename: Nari
authors.initials: N
authors.lastname: Seo
authors.affiliation: Graduate School of Analytical Science and Technology, Asia-Pacific Glycomics Reference Site, Chungnam National University, Daejeon, 34134, Republic of Korea.
authors.forename: Hyun Joo
authors.initials: HJ
authors.lastname: An
authors.affiliation: Department of Food and Nutrition, Chungnam National University, Daejeon, 34134, Republic of Korea.
authors.forename: Jae-Han
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Environmental Analysis Division, Korea Apparel Testing & Research Institute, Seoul, 02579, Republic of Korea.
authors.forename: Nam Yong
authors.initials: NY
authors.lastname: Cheong
authors.affiliation: Department of Biotechnology, Graduate School, Korea University, Seoul, 02841, Republic of Korea. khekim@korea.ac.kr.
authors.forename: Kyoung Heon
authors.initials: KH
authors.lastname: Kim
mesh_terms: D000464:Alginates / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D002850:Chromatography, Gel; D005285:Fermentation; D020723:Glucuronic Acid / Q000378:metabolism; D006603:Hexuronic Acids / Q000378:metabolism; D000459:Phaeophyceae / Q000378:metabolism*; D012624:Seaweed / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D020723:Glucuronic Acid
keywords: Acidic pretreatment; Alginate; Brown macroalgae; Depolymerization; Saccharification