Photobiohydrogen production and high-performance photobioreactor - Solar Energy Sciences and Engineering Applications - page 345

Table 11.2.1 Characteristics of different photobiohydrogen production microorganisms.

Classifications Microorganisms Strains Characteristics

Photoautotrophic
microorganisms

Green algae Chlamydomonas reinhardti

Scenedesmus obliquus
Platymonas subcordiformis

Carbon-free hydrogen production
Short growth cycle
High theoretical energy conversion
efficiency

Cyanobacteria Anabaena cylindrica
Nostoc muscorum
Plectonema boryanum
Oscillotoria limnetica
Aphanothece halophytica

Simple nutritional requirements
Inexpensive cultivation
Separating hydrogen and oxygen
evolution

Photoheterotrophic
microorganisms

Photosynthetic
bacteria

Rhodospirillum rubrum
Rhodobacter sphaeroides
Rhodopseudomonas palustris

Use of a wide range of the solar
spectrum
Lack of oxygen-evolving activity
Ability to consume organic
substrates derived from wastes

Figure 11.2.1 The photosynthetic system of green algae (Akkerman et al., 2002).

and absorbed by the antenna pigment; it is then transferred to the P680 reaction centre.
Subsequently, the strong oxidant generated after the excitation of P680 reaction centre
induces the splitting of water into oxygen, protons and electrons. Oxygen goes into the
mitochondria through the chloroplast membrane and is consumed by the respiration of
mitochondrial, and in the meantime supplied carbon dioxide is fixed. Protons are left in
the lumen while electrons are used to reduce the reaction center and transported to plas-
toquinone (PQ) after renewed excitations. Then, protons are picked up from stroma
producing fully reduced plastoquinone (PQH 2 ) that is diffused to the cytochrome com-
plex (Cyt b 6 f), via which electrons are transferred to the water-soluble electron carrier