earticle

영어

Saccharification of seaweed, Laminaria japonica (sea tangle) is an essential process for the bioethanol fermentation. The saccharification was carried out by thermal acid hydrolysis and the treatment of isolated marine bacteria, Bacillus sp. JS-1. The 10% seaweed slurry was hydrolyzed with 0.2% (v/v) H2SO4 at 121℃ for 60 min. The hydrolysate was neutralized by 5N NaOH and further degradation was carried out by the 10% (v/v, 1 g dcw/L) Bacillus sp. JS-1. The reducing sugar concentration and viscosity under the optimal saccharification process were 45.6±5.0 g/L and 24.9 cp, respectively. Total yield of the reducing sugar from Laminaria japonica was 69.1%. The isolated marine bacteria was identified as Bacillus sp. by 16s ribosomal RNA sequencing and named Bacillus sp. JS-1. SSF was carried out for the bioethanol production. Thermal acid hydrolysate of 10% Laminaria japonica slurry was fermented at 30℃, 200 rpm for 136 hr by the addition of the 4% (v/v, 0.39 g dcw/L) Bacillus sp. JS-1 and 4% (v/v, 0.45 g dcw/L) yeast. The highest ethanol concentration of 7.7 g/L with 33% of theoretical yield was obtained from 10% Laminaria japonica slurry fermented with Pichia angoporae.