Feasibility study of hydrogen production from cellulosic hydrolyates using isolated bacterial strains

  • PhD student Yung-Chung Lo, Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan, Taiwan
  • PostDoc Shing-Der Chen, Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan, Taiwan
  • PostDoc Ganesh Saratale, Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan, India
  • PostDoc Chun-Yen Chen, Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan, Taiwan
  • Master student Wei-Chung Lu, Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan, Taiwan
  • Master student Yi-Chen Su, Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan, Taiwan
  • Dr Ming-Der Bai, Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan, Taiwan
  • Professor Jo-Shu Chang, Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan, Taiwan

    • Cellulose is the major constitute of plant biomass and highly available in agricultural waste and industrial effluents such as pulp/paper and food industry. In nature, cellulosic feedstocks are degraded by the cooperation of microorganisms where several cellulase enzymes are involved. Generation of H2 from lignocellulosic materials via dark fermentation usually requires substrate pretreatment procedures, which contribute significantly to the production cost. Therefore, it is of great demand to develop a more cost-effective and technically feasible cellulosic H2 production process. This study aimed to produce H2 fermentatively using cellulosic hydrolysates produced from microbial/enzymatic hydrolysis. Nine microbial strains were isolated from a mixed culture having high efficiency in cellulose hydrolysis. 16S rDNA sequencing and phylogenetic analysis discovered that all of those strains belong to Cellulomonas genus. Those strains were well studied in the presence of raw cellulosic materials with the measurement of the produced cellulase enzyme activities (i.e., endoglucanase, exoglucanase, cellobiase and xylanase). The results showed that the pure isolates, especially Cellulomonas uda strains, had higher hydrolysis efficiency on rice husk. The hydrolysates from rice husk were then evaluated for their potential in H2 production using several H2-producing bacterial isolates (e.g., Clostridium butyricum, Cl. pasteurianum, etc.). The feasibility of integrating cellulosic feedstock pretreatment and dark fermentation technology was also assessed to identify the commercial viability of this biomass-to-energy approach.