Effects of gassing, pH, quenching agents and photodynamically active compounds on photobleaching and photoinhibition of the cyanobacteriumAnabaena variabilis

✍ Scribed by G. Agel; W. Nultsch

• Publisher: Springer
• Year: 1987
• Tongue: English
• Weight: 544 KB
• Volume: 149
• Category: Article
• ISSN: 0302-8933
• DOI: 10.1007/bf00425084

✦ Synopsis

The findings presented in this paper support the suggestion that in the cyanobacterium Anabaena variabilis photobleaching is the result of an increased intracellular level of singlet molecular oxygen, whereas photoinhibition is controlled by a different molecular mechanism. Photobleaching of Anabaena trichomes can be prevented effectively by gassing with argon, nitrogen and carbon dioxide as well as by treatment with the 102 quenchers sodium azide and crocetin, and finally, with 3-(3,4-dichlorophenyl)-l,l-dimethylurea (DCMU). On the other hand, photodynamically active compounds, capable of ~Oz generation, increase photobleaching drastically. Thus, photobleaching is probably caused by singlet molecular oxygen. Photoinhibition studied with the aid of the fluorescence induction was not prevented by most of the treatments which prevent photobleaching. Therefore, different control mechanisms have to be assumed for this process.