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The waste product from salted Undaria pinnatifida (sea mustard) processing was fermented to produce bioethanol by Saccharomyces cerevisiae KCCM 1129 at laboratory and pilot development unit (PDU) scales. Thermal acidic hydrolysis of salted U. pinnatifida was conducted with 75 mM HSO at 121℃ for 60 min and the addition of 1.4 KNU/mL Termamyl 120L. A total monosaccharide concentration of 19.3 g/L and 32.2% conversion from 59.9 g/L total carbohydrate using 130 g dw/L salted U. pinnatifida were achieved. Ethanol fermentations in 5 and 500 L fermenters were carried out to produce 8.5 g/L of ethanol with an ethanol yield (Y) of 0.44 at 24 h and 7.9 g/L with Y of 0.41 at 18 h, respectively. The fermentation time of the PDU-scale reaction was reduced due to differences in the impeller type and geometry of the fermenters. [ABSTRACT FROM AUTHOR]

Highlights: [•] Thermal acid hydrolysis and enzymatic saccharification resulted in 43.5g/L sugars. [•] Ethanol concentration of 20.5g/L was obtained using S. stipitis KCTC 7228. [•] Glucose uptake increased at HMF concentrations <5g/L in the fermentation medium. [•] HMF was converted to 2,5-bis-hydroxymethylfuran by S. stipitis KCTC 7228. [Copyright &y& Elsevier]

Hyper thermal (HT) acid hydrolysis of Kappaphycus alvarezii , a red seaweed, was optimized to 12% (w/v) seaweed slurry content, 180 mM H 2 SO 4 at 140 °C for 5 min. The maximum monosaccharide concentration of 38.3 g/L and 66.7% conversion from total fermentable monosaccharides of 57.6 g/L with 120 g dw/L K. alvarezii slurry were obtained from HT acid hydrolysis and enzymatic saccharification. HT acid hydrolysis at a severity factor of 0.78 efficiently converted the carbohydrates of seaweed to monosaccharides and produced a low concentration of inhibitory compounds. The levels of ethanol production by separate hydrolysis and fermentation with non-adapted and adapted Kluyveromyces marxianus to high concentration of galactose were 6.1 g/L with ethanol yield ( Y EtOH ) of 0.19 at 84 h and 16.0 g/L with Y EtOH of 0.42 at 72 h, respectively. Development of the HT acid hydrolysis process and adapted yeast could enhance the overall ethanol fermentation yields of K. alvarezii seaweed. [ABSTRACT FROM AUTHOR]