title: Acid pretreatment and enzymatic saccharification of brown seaweed for polyhydroxybutyrate (PHB) production using Cupriavidus necator.
abstract: The brown seaweed Sargassum sp. was used as a feedstock to produce polyhydroxybutyarte (PHB) using Cupriavidus necator PTCC 1615. In order to release monomeric sugars, dilute acid hydrolysis of Sargassum sp. biomass was followed by enzymatic saccharification. In addition, the effect of different nitrogen sources was evaluated for PHB production. The fermentation of hydrolysate with the ammonium sulfate as selected nitrogen source resulted PHB yield of 0.54±0.01g/g reducing sugar. Then, NaCl was used as external stress factor which was added to the media. Addition of 8g/L NaCl had a positive impact on high PHB yield of 0.74±0.01g/g reducing sugar. Increasing trend of NaCl concentration to 16g/L was found to inhibit the production of PHB. Based on obtained results using 20g/L of reducing sugar, at desired condition the highest cell dry weight and PHB concentrations were 5.36±0.22 and 3.93±0.24g/L, respectively. The findings of this study reveal that Sargassum sp. is a promising feedstock for biopolymer production. The characteristics of produced PHB were analyzed by FTIR, differential scanning calorimetry and1H NMR.
authors.affiliation: Biotechnology Research Laboratory, Faculty of Chemical Engineering, Babol Noshirvani University of Technology, Babol, Iran.
authors.forename: Nahid
authors.initials: N
authors.lastname: Azizi
authors.affiliation: Biotechnology Research Laboratory, Faculty of Chemical Engineering, Babol Noshirvani University of Technology, Babol, Iran. Electronic address: najafpour8@gmail.com.
authors.forename: Ghasem
authors.initials: G
authors.lastname: Najafpour
authors.affiliation: Department of Environmental Science, Faculty of Natural Resources, Tarbiat Modares University (TMU), Nour, Iran.
authors.forename: Habibollah
authors.initials: H
authors.lastname: Younesi
mesh_terms: D018533:Biomass; D001709:Biotechnology; D002480:Cellulase / Q000378:metabolism*; D020118:Cupriavidus necator / Q000187:drug effects / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis / Q000187:drug effects; D011091:Polyesters / Q000378:metabolism*; D012624:Seaweed / Q000737:chemistry*; D012965:Sodium Chloride / Q000494:pharmacology; D000073893:Sugars / Q000378:metabolism*
chemical_list: D011091:Polyesters; D000073893:Sugars; C107955:poly(4-hydroxybutanoate); D012965:Sodium Chloride; D002480:Cellulase
keywords: Cupriavidus necator; Hydrolysis; Macroalgae; Osmotic stress; Polyhydroxybutyrate