Sulfuric acid hydrolysis and detoxification of red alga Pterocladiella capillacea for bioethanol fermentation with thermotolerant yeast Kluyveromyces marxianus.
One-step sulfuric acid saccharification of the red alga Pterocladiella capillacea was optimized, and various detoxification methods (neutralization, overliming, and electrodialysis) of the acid hydrolysate were evaluated for fermentation with the thermotolerant yeast Kluyveromyces marxianus. A proximate composition analysis indicated that P. capillacea was rich in carbohydrates. A significant galactose recovery of 81.1 ± 5% was also achieved under the conditions of a 12% (w/v) biomass load, 5% (v/v) sulfuric acid, 121°C, and hydrolysis for 30 min. Among the various detoxification methods, electrodialysis was identified as the most suitable for fermentable sugar recovery and organic acid removal (100% reduction of formic and levulinic acids), even though it failed to reduce the amount of the inhibitor 5-HMF. As a result, K. marxianus fermentation with the electrodialyzed acid hydrolysate of P. capillacea resulted in the best ethanol levels and fermentation efficiency.
Department of Sea Food Science, National Kaohsiung Marine University, Nan-Tzu, Kaohsiung 81143, Taiwan, R.O.C.
Chien-Hui
CH
Wu
Wei-Chen
WC
Chien
Han-Kai
HK
Chou
Jungwoo
J
Yang
Hong-Ting Victor
HT
Lin
D056804:Biofuels; D018533:Biomass; D019149:Bioreactors; D000431:Ethanol / Q000032:analysis / Q000378:metabolism*; D005285:Fermentation; D005561:Formates / Q000378:metabolism; D005662:Furaldehyde / Q000031:analogs & derivatives / Q000378:metabolism; D006868:Hydrolysis; D007716:Kluyveromyces / Q000378:metabolism*; D007982:Levulinic Acids / Q000378:metabolism; D000461:Rhodophyta / Q000737:chemistry*; D013464:Sulfuric Acids / Q000737:chemistry*
D056804:Biofuels; D005561:Formates; D007982:Levulinic Acids; D013464:Sulfuric Acids; C030544:formic acid; D000431:Ethanol; C008046:5-hydroxymethylfurfural; D005662:Furaldehyde; C033158:sulfuric acid; C032246:levulinic acid