The effects of NaCl concentration on bio-hydrogen production and microbial community by dark-fermentation were evaluated. The examined NaCl concentration was varied from 0 to 5%. When NaCl concentration ranged from 0 to 3%, the hydrogen production was insignificantly affected. 4% or more NaCl concentration decreased accumulated hydrogen production and the lag time was longer. In addition, the metabolite pathway of the bacteria were shifted from butyrate to acetate by microbial community changes with high concentration of NaCl. FISH analysis was achieved to analyze the microbial community after the dark-fermentation performance. Hydrogen producing bacteria, Clostridium sp. Cluster I and Cluster XI, was dominated with 0 ~ 3% of NaCl, while Eubacteria, general bacteria, was dominated with 4 ~ 5% of NaCl. Therefore, the growth and hydrogen production of the hydrogen producing bacteria were inhibited with over 4% of NaCl.

• 장산(경희대학교 공과대학 환경공학과·환경연구센터) | Shan Zhang
• 이윤희(경희대학교 공과대학 환경공학과·환경연구센터) | Yunhee Lee
• 김태형(경희대학교 공과대학 환경공학과·환경연구센터) | Tae-Hyeong Kim
• 황선진(경희대학교 공과대학 환경공학과·환경연구센터) | Sun-Jin Hwang Corresponding author