Evaluation of 2,3-butanediol production from red seaweed Gelidium amansii hydrolysates using engineered Saccharomyces cerevisiae.

Hyper thermal (HT) acid hydrolysis of red seaweed Gelidium amansii was performed using 12% (w/v) slurry and an acid mix concentration of 180 mM at 150 °C for 10 min. Enzymatic saccharification when using a combination of Celluclast 1.5 L and Ctec2 at a dose of 16 U/mL led to the production of 12.0 g/L of reducing sugar with an the efficiency of enzymatic saccharification (Es) of 13.2%. After the enzymatic saccharification, 2,3-butanediol (2,3-BD) fermentation was carried out using an engineered S. cerevisiae strain. The use of HT acid-hydrolyzed medium with 1.9 g/L of 5-HMF showed a reduction in the lag time from 48 to 24 h. The 2,3-BD concentration and yield at 72 h were 14.8 g/L and 0.30, respectively. Therefore, HT acid hydrolysis and the use of the engineered S. cerevisiae strain can enhance the overall 2,3-BD yields from G. amansii seaweed.