Membrane Proteins of Photosynthesis: Structure - Function - Biotechnology

Abstract

Prerequisite for the structural and functional investigation of membrane proteins of photosynthesis, i.e. photosystem 1 (PS 1), photosystem 2 (PS2) and the cytochrom b₆fcomplex (b₆f) is the mass production of such complexes in appropriate systems. Mesophilic (i.e. Synechocystis PCC 6803) and thermophilic (i.e. Synechococcus elongatus) cyanobacteria can be grown in mass culture under controlled conditions in a new developed 25 L photobioreactor especially designed for these organisms; its main features are an illumination unit on wheels and the use of transparent polyamid foil instead of glass which enables a safe in situ sterilisation. Under pH-, light, gas-mixing and temperature-controlled condition the yield of cells can be more than doubled, resulting in more than 100 g cells (wet weight) out of 25 L culture in about 3 days. This set-up may be interesting for various applications in biotechnology involving cyanobacteria and green algae.