Observation of the circadian photosynthetic rhythm in cyanobacteria with a dissolved-oxygen meter

This research investigated the feasibility of employing a dissolved-oxygen (DO) meter to monitor the circadian photosynthetic rhythm of cyanobacteria. Three cyanobacteria, Synechocystis sp. PCC 6803, Synechococcus sp. PCC 7942, and Cyanothece RF-1, were used to examine the proposed method. Their circadian photosynthetic rhythms were successfully observed; moreover, the different characteristics among these rhythms were clearly exhibited. The advantage of this method is that experiments can be conducted continuously and automatically, essentially eliminating the bother of long-period assays and a large amount of the labor undertaken in conventional methods. (C) 2003 Elsevier Ireland Ltd. All rights reserved.