The other is biological route, including direct biophotolysis, indirect biophotolysis, photo fermentation, hydrogen synthesis via the water-gas-shift reaction of photoheterotrophic bacteria, dark fermentation and microbial fuel cells etc. 另一类是利用生物转化途径转换制氢,包括直接生物光解,间接生物光解,光发酵,光合异养细菌水气转移反应合成氢气,暗发酵和微生物燃料电池等技术。